Products 1.
Separ Separat atio ion n of pig pig iro iron n and and slag slag (Pro (Proce cess ss & Conditions)
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Pig Pig iro iron n (co (comp mpos osit itio ion, n, facto actors rs aff affecti ecting ng quality)
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Slag Slag (Pro (Prope pert rtie ies, s, com compo posi siti tion on,, uses uses))
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Calcu Calcula lati tion on for 1 ton ton of hot hot met metal al (how (how much much ore, coke, flux and slag generation)
SEPARATION OF PIG IRON AND SLAG
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Blast furnace slag is a combination of silica and other non-ferrous components of iron ore, ash from coke used as a reducing material, and limestone auxiliary material. limestone may seem unrelated to the production of iron, but it is an essential auxiliary material. material. During the process of reducing iron ore it is necessary to remove slag. The added limestone fuses with non ferrous components ,lowers their melting point making it easier to separate from iron. Also its specific gravity is less than that of pig iron, during the heating process the molten slag rises above the pig iron allowing it to be easily separated and recovered .
SEPARATION OF PIG IRON AND SLAG
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Blast furnace slag is a combination of silica and other non-ferrous components of iron ore, ash from coke used as a reducing material, and limestone auxiliary material. limestone may seem unrelated to the production of iron, but it is an essential auxiliary material. material. During the process of reducing iron ore it is necessary to remove slag. The added limestone fuses with non ferrous components ,lowers their melting point making it easier to separate from iron. Also its specific gravity is less than that of pig iron, during the heating process the molten slag rises above the pig iron allowing it to be easily separated and recovered .
Ruchit Ruchitaa Deulka Deulkar r (13118075)
Separation of pig iron and slag •
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1) 2) 3) 4) 5) 6) 7) 8)
Condition The slag must have the affinity for absorbing impurities i.e. gangue from charge along with other deleterious impurities which affect the quality of hot metal Reduct Reduction ion in the activity activity of other metal metal oxide oxide . Lowering the M.P. M.P. of unwanted unwanted materials materials . Solubili Solubility ty :- Two phases phases –value –value and and slag shoul should d be immiscib immiscible le into into each each other. Sufficient Sufficient differe difference nce in the specific specific gravities gravities of the two phases like like slag and metal. Slag should should have have no solubili solubility ty for metal metal value. value. Slag should should have have sufficien sufficientt fluidity fluidity The melting melting point point of the slag is to to be neith neither er too too high high nor nor too too low low The final slag is to be be fluid enough enough so that it is possible to drain drain it through through tap hole
SEPARATION OF PIG IRON AND SLAG
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Blast furnace slag is a combination of silica and other non-ferrous components of iron ore, ash from coke used as a reducing material, and limestone auxiliary material. limestone may seem unrelated to the production of iron, but it is an essential auxiliary material. material. During the process of reducing iron ore it is necessary to remove slag. The added limestone fuses with non ferrous components ,lowers their melting point making it easier to separate from iron. Also its specific gravity is less than that of pig iron, during the heating process the molten slag rises above the pig iron allowing it to be easily separated and recovered .
Ruchit Ruchitaa Deulka Deulkar r (13118075)
Separation of pig iron and slag •
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1) 2) 3) 4) 5) 6) 7) 8)
Condition The slag must have the affinity for absorbing impurities i.e. gangue from charge along with other deleterious impurities which affect the quality of hot metal Reduct Reduction ion in the activity activity of other metal metal oxide oxide . Lowering the M.P. M.P. of unwanted unwanted materials materials . Solubili Solubility ty :- Two phases phases –value –value and and slag shoul should d be immiscib immiscible le into into each each other. Sufficient Sufficient differe difference nce in the specific specific gravities gravities of the two phases like like slag and metal. Slag should should have have no solubili solubility ty for metal metal value. value. Slag should should have have sufficien sufficientt fluidity fluidity The melting melting point point of the slag is to to be neith neither er too too high high nor nor too too low low The final slag is to be be fluid enough enough so that it is possible to drain drain it through through tap hole
Separation of pig iron and slag Condition The slag must have the affinity for absorbing impurities i.e. gangue from charge along with other deleterious impurities which affect the quality of hot metal 1) Reduct Reduction ion in the activity activity of other metal metal oxide oxide . 2) Lowering the M.P. M.P. of unwanted unwanted materials materials . 3) Solubili Solubility ty :- Two phases phases –value –value and and slag shoul should d be immiscib immiscible le into into each each other. 4) Sufficient Sufficient differe difference nce in the specific specific gravities gravities of the two phases like like slag and metal. 5) Slag should should have have no solubili solubility ty for metal metal value. value. 6) Slag should should have have sufficien sufficientt fluidity fluidity 7) The melting melting point point of the slag is to to be neith neither er too too high high nor nor too too low low 8) The final slag is to be be fluid enough enough so that it is possible to drain drain it through through tap hole As temperature increases viscosity decreases so fluidity increases , this shows that temperature in blast furnace for separation process of pig iron iron and slag can not be only decided by melting point of slag but also by fluidity of slag. •
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Md Tan anve veer er Al Alam am (13 (1311 1180 8043) 43)
PIG IRON It is the molten iron extracted from iron ore by Blast Furnace. During the process of smelting, the liquid iron absorbs and combines with a considerable considerable quantity of carbon, sulphur, silicon, phosphorus, and manganese from the ore and coke. Some of the carbon is chemically combined with the iron in the form of iron carbide, while the remainder exists as a form of free carbon called graphite. Compositions – Iron Iron (Fe) (Fe) – 93.1 93.1 - 95.4% 95.4% Carbon Carbon (C) – 3.5 - 4.5% 4.5% Mangan Manganese ese (Mn) (Mn) – 0.4 0.4 - 1.0% 1.0% Silico Silicon n (Si) (Si) – 0.5 0.5 - 1.2% 1.2% Phosphor Phosphorus us (P) (P) – 0.15% 0.15% Sulfur Sulfur (S) (S) – 0.04% 0.04% •
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Silica and other constituents constituents of dross(Mn ,P ,S ,etc), which makes Pig Iron very very brittle and not useful directly as a material except for limited applications.
Pig iron is graded according to the appearance of its fracture. It is used in puddling furnaces, and more more recently recently into steel. steel.
PIG IRON It is the molten iron extracted from iron ore by Blast Furnace. During the process of smelting, the liquid iron absorbs and combines with a considerable considerable quantity of carbon, sulphur, silicon, phosphorus, and manganese from the ore and coke. Some of the carbon is chemically combined with the iron in the form of iron carbide, while the remainder exists as a form of free carbon called graphite. Compositions – Iron Iron (Fe) (Fe) – 93.1 93.1 - 95.4% 95.4% Carbon Carbon (C) – 3.5 - 4.5% 4.5% Mangan Manganese ese (Mn) (Mn) – 0.4 0.4 - 1.0% 1.0% Silico Silicon n (Si) (Si) – 0.5 0.5 - 1.2% 1.2% Phosphor Phosphorus us (P) (P) – 0.15% 0.15% Sulfur Sulfur (S) (S) – 0.04% 0.04% •
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Silica and other constituents constituents of dross(Mn ,P ,S ,etc), which makes Pig Iron very very brittle and not useful directly as a material except for limited applications.
Pig iron is graded according to the appearance of its fracture. It is used in puddling furnaces, and more more recently recently into steel. steel. Pig iron can also be used to to produce produce gray iron. iron. Some pig iron grades are suitable for producing ductile iron. Gaurav Singh (13118025)
Factors affecting pig iron qualities •
Conc. Of Carbon : Increase in the concentration of carbon leads to occurrence of graphite phase, now increase in graphite phase increases the brittleness of pig iron and act as a source of cracks and fracture fracture..
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Conc. Of Sulphur : Lowering the sulphur content of pig iron gives cleaner and better cast products free from pin holes, holes, surface dross and improvement in mechanical properties.
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Conc. Of Phosphorous: It leads to formation of steadite (Fe3P) which solidifies at grain boundaries. Steadite is a har ard d, brittle constitute which reduces toughness and ductility and can’t be elim elimin inat ated ed by heat heat trea treatm tmen ent. t.
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Conc. Of Manganese: Manganese: Mn along with S&P segregate segregate at at grain boundaries and affect the impact strength decreases elongation
Factors affecting pig iron qualities •
Conc. Of Carbon : Increase in the concentration of carbon leads to occurrence of graphite phase, now increase in graphite phase increases the brittleness of pig iron and act as a source of cracks and fracture fracture..
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Conc. Of Sulphur : Lowering the sulphur content of pig iron gives cleaner and better cast products free from pin holes, holes, surface dross and improvement in mechanical properties.
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Conc. Of Phosphorous: It leads to formation of steadite (Fe3P) which solidifies at grain boundaries. Steadite is a har ard d, brittle constitute which reduces toughness and ductility and can’t be elim elimin inat ated ed by heat heat trea treatm tmen ent. t.
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Conc. Of Manganese: Manganese: Mn along with S&P segregate segregate at at grain boundaries and affect the impact strength decreases elongation percent and also fatigue strength. strength. Vishal Kumar Rana (13118107)
SLAG – slag is the by-product left over after a hot metal has been separated from iron ore. Slag is usually a mixture of metal oxides and silicon dioxide.
Weight Percent (wt%) Slag Constituent Lime (CaO) Magnesia (MgO) Silica (Si02) Alumina(Al203) Sulfur (S) Iron Oxide (Fe0) Manganese Oxide (MnO) Na2O + K2O
GLOBAL 32 to 45 5 to 15 32 to 42 7 to 16 1 to 2 0.1 to 1.5 0.2 to 1.0 0 to1
INDIAN 30 to 35 2 to 4 29 to 36 24 to 29 0.8 to 1.2 0.5 to 2.5 0.5 to 1.3 0 to1
SLAG PROPERTIES – The slag should be fluid (viscosity) so that it can be removed easily during tapping. This ratio should be 1.1-1.2 for best slagging. Basicity -
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SLAG – slag is the by-product left over after a hot metal has been separated from iron ore. Slag is usually a mixture of metal oxides and silicon dioxide.
Weight Percent (wt%) Slag Constituent Lime (CaO) Magnesia (MgO) Silica (Si02) Alumina(Al203) Sulfur (S) Iron Oxide (Fe0) Manganese Oxide (MnO) Na2O + K2O
GLOBAL 32 to 45 5 to 15 32 to 42 7 to 16 1 to 2 0.1 to 1.5 0.2 to 1.0 0 to1
INDIAN 30 to 35 2 to 4 29 to 36 24 to 29 0.8 to 1.2 0.5 to 2.5 0.5 to 1.3 0 to1
SLAG PROPERTIES – The slag should be fluid (viscosity) so that it can be removed easily during tapping. This ratio should be 1.1-1.2 for best slagging. Basicity Its density is lower than that of the hot metal, so we can easily separate it. It has good permeability (in slag formation zone) and also has appropiate melting temperature temperature (neither too high nor too low), Low surface tension, High diffusivity. High internal friction values and particle interlocking properties, which gives it a higher strength. Low surface surface tension, tension, Hi h diffusivi diffusivitt , Oxidatio Oxidation n otenti otential. al. NITIN PATEL 1311805 13118050 0 •
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SLAG APPLICATIONS Operational uses (in blast furnace):
Air-cooled slag
• Shields molten steel against atmospheric oxidation. • Acts as a thermal barrier to prevent heat losses. • Shields the refractory lining particularly in electric arc furnace. • Control heat transfer from the post combustion flame.
The molten slag flows into a cooling yard, where it is cooled slowly by natural cooling and by spraying with water. This results in a crystalline, rock-like aircooled slag. Common uses are as aggregates in ready-mix concrete, precast concrete, hot mix asphalt aggregate. Crushed and graded - for concrete aggregates, concrete sand, glass insulation wool. •
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USES (after tapping): When it is ejected from a blast furnace, the slag is molten at a temperature of approximately 1,500 ℃. Depending on the cooling method used, it is classified either as air-cooled slag or granulated slag.
Granulated slag The molten slag is cooled rapidly by jets of pressurized water, resulting in a vitreous, granulated slag. The principal use is as Cement replacement (when ground), replacing 30-50% of Portland Cement in 'normal' concrete, but can replace up to 70% in •
SLAG APPLICATIONS Operational uses (in blast furnace):
Air-cooled slag
• Shields molten steel against atmospheric oxidation. • Acts as a thermal barrier to prevent heat losses. • Shields the refractory lining particularly in electric arc furnace. • Control heat transfer from the post combustion flame.
The molten slag flows into a cooling yard, where it is cooled slowly by natural cooling and by spraying with water. This results in a crystalline, rock-like aircooled slag. Common uses are as aggregates in ready-mix concrete, precast concrete, hot mix asphalt aggregate. Crushed and graded - for concrete aggregates, concrete sand, glass insulation wool. •
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USES (after tapping): When it is ejected from a blast furnace, the slag is molten at a temperature of approximately 1,500 ℃. Depending on the cooling method used, it is classified either as air-cooled slag or granulated slag.
Granulated slag The molten slag is cooled rapidly by jets of pressurized water, resulting in a vitreous, granulated slag. The principal use is as Cement replacement (when ground), replacing 30-50% of Portland Cement in 'normal' concrete, but can replace up to 70% in specialist applications such as marine concrete. Other uses include, glass making, trace elements in agriculture, concrete block manufacture. used as raw material cast stone, glass, fertilizer, enamel, ceramic, etc. •
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RAVI SHANKAR YADAV (13118072)
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Mass Calculations for 1 tonne of hot metal Mass flow diagram Appropriate compositions have been given which are to be used in calculations :
Blast Furnace
Mass Calculations for 1 tonne of hot metal Mass flow diagram Appropriate compositions have been given which are to be used in calculations :
Blast Furnace
The calculations are based on individual mass balance of different elements involved in the Blast furnace process wherein the total elemental input from all sources is equated with total corresponding elemental output ( product + waste ) as shown in example on next slide. Ritvik Vipra, MMED 13118106 Kotipalli Mahitha , MMED 13118036
Mass Calculations for 1 tonne of hot metal Coke consumption is 800Kg per tonne of hot metal.
Mass Balances: Amount of ore Fe- Balance: Feore = Fehot metal (85/100)*(112/160)* x = 1000*(95/100) x = 1596.64 Kg = Amount of Ore required
Carbon Balance: Ccoke + Cflux = CB.F gas + Chot-metal 0.85*800=0.95*299.37*(12/100)=C B.Fgas +0.0036* 1000
CB.F gas= 678.12 kg = 56.51 Kmoles CO molar fraction = 28/(12+28) = 0.7 CO2 molar fraction = 12/(12+28) = 0.3 Amount of CO and CO2 present is 39.56 and 16.94 moles respectively.
Amount of flux
Amount of slag
Ca Balance: (95/100)*(40/100)* z = y *(40/100)*(40/56) z = 0.75 y Al2O3 Balance: (5/100)* x = (20/100)* y y = 399.16 Kg = Amount of Slag Produced By substituting y value z can be found, z = 299.37 K = Amount of Flux to be added
Oxygen Balance(in moles): Oxygen supplied (with air blast) = Oxygen required to produce CO,CO2 - Oxygen supplied through ore = (39.56*(0.5) +16.94) – 950*(48/112)*(1/32) Oxygen in air blast = 24.01 Kmol So ,Nitrogen in air blast =24.01*(79/21)=90.32
Mass Calculations for 1 tonne of hot metal Coke consumption is 800Kg per tonne of hot metal. Amount of flux
Mass Balances:
Ca Balance: (95/100)*(40/100)* z = y *(40/100)*(40/56) z = 0.75 y Al2O3 Balance: (5/100)* x = (20/100)* y y = 399.16 Kg = Amount of Slag Produced By substituting y value z can be found, z = 299.37 K = Amount of Flux to be added
Amount of ore Fe- Balance: Feore = Fehot metal (85/100)*(112/160)* x = 1000*(95/100) x = 1596.64 Kg = Amount of Ore required
Carbon Balance: Ccoke + Cflux = CB.F gas + Chot-metal 0.85*800=0.95*299.37*(12/100)=C B.Fgas +0.0036* 1000
CB.F gas= 678.12 kg = 56.51 Kmoles CO molar fraction = 28/(12+28) = 0.7 CO2 molar fraction = 12/(12+28) = 0.3 Amount of CO and CO2 present is 39.56 and 16.94 moles respectively.
Amount of slag
Oxygen Balance(in moles): Oxygen supplied (with air blast) = Oxygen required to produce CO,CO2 - Oxygen supplied through ore = (39.56*(0.5) +16.94) – 950*(48/112)*(1/32) Oxygen in air blast = 24.01 Kmol So ,Nitrogen in air blast =24.01*(79/21)=90.32
Total B.F Top Gas = 90.32+39.56+16.94 = 146.82 Kmol = 146.82 * 22.4 Nm3 = 3289 Nm3 Ritvik Vipra, MMED Volume of B.F Top gas = 3289 Nm3 13118106 Kotipalli Mahitha , MMED 13118036
DIRECT(SOLID-CARBON) and INDIRECT REDUCTION OF IRON ORE IN BLAST FURNACE Rakesh kumar,MT-3,13118067 DIRECT (SOLID CARBON INDIRECT (GASEOUS REACTIONS INVOLVED:REDUCTION) CARBON REDUCTION) Indirect reduction:Reaction between preheated and Here Fe2O3 reacts with CO with 1) 3Fe2O3 + CO = 2Fe3O4 + CO2 partially reduced FeO with solid intermediate products Fe3O4 2) Fe3O4 + CO = 3FeO + CO2 carbon and FeO to form Fe 3) FeO + CO = Fe + CO2 Its endothermic reaction, al though ,It requires carbon 1/3 amount of each mole of Fe
Its exothermic reaction , but CO comes from coke ,equilibrium limitation prevent complete combustion to CO
Its fuel-saving carbon reduction
As exothermic ,it yields large thermal energy
It occurs at lower part of blast furnace . It is responsible for 3540% reduction.
It takes place approximately in stack. It is responsible for 6065% of reduction of ore .
Since some of the heat generated by gaseous reduction (or more accurately by the combustion of coke to CO) can be used to
Direct reduction:1) FeO + C = Fe +CO Calculation in terms of coke:Indirect reduction:Fe2O3+7.5C+3.75O=2Fe+4.5CO+3CO2 2 moles of Fe:7.5 moles of carbon So for 1 kg fe ,0.803kg of carbon Direct reduction:Fe2O3+2.33C+3O=2Fe+1.28CO+.85CO2
DIRECT(SOLID-CARBON) and INDIRECT REDUCTION OF IRON ORE IN BLAST FURNACE Rakesh kumar,MT-3,13118067 DIRECT (SOLID CARBON INDIRECT (GASEOUS REACTIONS INVOLVED:REDUCTION) CARBON REDUCTION) Indirect reduction:Reaction between preheated and Here Fe2O3 reacts with CO with 1) 3Fe2O3 + CO = 2Fe3O4 + CO2 partially reduced FeO with solid intermediate products Fe3O4 2) Fe3O4 + CO = 3FeO + CO2 carbon and FeO to form Fe 3) FeO + CO = Fe + CO2 Its endothermic reaction, al though ,It requires carbon 1/3 amount of each mole of Fe
Its exothermic reaction , but CO comes from coke ,equilibrium limitation prevent complete combustion to CO
Its fuel-saving carbon reduction
As exothermic ,it yields large thermal energy
It occurs at lower part of blast furnace . It is responsible for 3540% reduction.
It takes place approximately in stack. It is responsible for 6065% of reduction of ore .
Since some of the heat generated by gaseous reduction (or more accurately by the combustion of coke to CO) can be used to compensate for the heat requirements of fuel-saving carbon reduction. Both types of reaction are therefore encountered in the blast furnace
Direct reduction:1) FeO + C = Fe +CO Calculation in terms of coke:Indirect reduction:Fe2O3+7.5C+3.75O=2Fe+4.5CO+3CO2 2 moles of Fe:7.5 moles of carbon So for 1 kg fe ,0.803kg of carbon Direct reduction:Fe2O3+2.33C+3O=2Fe+1.28CO+.85CO2 2moles of Fe :2.33 moles of C So for 1 kg Fe,0.23kg of C is required
Temperature profile of the blast furnace
It can be seen that the softening/melting zone is located in an area where temperatures are between 2100 and 2600°F. The temperature differences in the furnace are large. Ore burden start melting at 2100°F .Different iron oxide formation depending on the temperature is shown in the diagram .
By Harsh Vardhan Singh
Temperature profile of the blast furnace
By Harsh Vardhan Singh
It can be seen that the softening/melting zone is located in an area where temperatures are between 2100 and 2600°F. The temperature differences in the furnace are large. Ore burden start melting at 2100°F .Different iron oxide formation depending on the temperature is shown in the diagram .
Kadiyam Yaswant Reddy ; Enrollment No.13118035;Pressure Profile of Blast Furnace. •
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Pressure profile of Blast Furnace is Mainly dependent on hot blast intake velocity and amount, top gas exit velocity and amount, amount of CO and CO2 produced in different Zones of the Blast Furnace, the amount of CO and CO2 consumed in the reduction reactions and Boudouard Reaction respectively and the amount of moisture levels near tuyeres that produce water gas. Chemical Kinetics and Thermodynamics of the above processes are studied to know the Gaseous production rates and temperatures at different Zones that govern the Pressures in different zones of Blast Furnace. •
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Several mathematical models have been developed to find the pressure profile of the Blast Furnace. This method can be verified and modified accordingly, further the relevance of equations available for estimation can be improved with experience. Method using the analogy of gas flow to electrical conductivity with the use of electrically conductive paper. This method is Time consuming but can be useful for the zones where Mathematical Equations are unavailable for assumptions.
Kadiyam Yaswant Reddy ; Enrollment No.13118035;Pressure Profile of Blast Furnace. •
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Pressure profile of Blast Furnace is Mainly dependent on hot blast intake velocity and amount, top gas exit velocity and amount, amount of CO and CO2 produced in different Zones of the Blast Furnace, the amount of CO and CO2 consumed in the reduction reactions and Boudouard Reaction respectively and the amount of moisture levels near tuyeres that produce water gas. Chemical Kinetics and Thermodynamics of the above processes are studied to know the Gaseous production rates and temperatures at different Zones that govern the Pressures in different zones of Blast Furnace. •
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Several mathematical models have been developed to find the pressure profile of the Blast Furnace. This method can be verified and modified accordingly, further the relevance of equations available for estimation can be improved with experience. Method using the analogy of gas flow to electrical conductivity with the use of electrically conductive paper. This method is Time consuming but can be useful for the zones where Mathematical Equations are unavailable for assumptions. The pressure profile given here is developed using several Mathematical models and appropriate assumptions. It is showing minimum possible errors.
Deadman Zone •
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Deadman zone(coke) is the packed coke bed with dense skin structure in the lower zone of blast furnace occupying a region extending from the hearth up to the tuyers and a roughly conical region above the t uyers up into the bosh Depending on the force and pressure distribution along the l ower zone of blast furnace as well as the angle of repose for the coke bed which is exposed towards the preheated air(with PCI,natural gas) formation of conical shaped almost stagnant zone,deadman zone(containing pile of coke) takes place. Deadman coke may float or sit in the hearth depending o n the force balance between buoyancy of the coke and weight of burden actually applied on the deadman
Deadman Zone •
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Deadman zone(coke) is the packed coke bed with dense skin structure in the lower zone of blast furnace occupying a region extending from the hearth up to the tuyers and a roughly conical region above the t uyers up into the bosh Depending on the force and pressure distribution along the l ower zone of blast furnace as well as the angle of repose for the coke bed which is exposed towards the preheated air(with PCI,natural gas) formation of conical shaped almost stagnant zone,deadman zone(containing pile of coke) takes place. Deadman coke may float or sit in the hearth depending o n the force balance between buoyancy of the coke and weight of burden actually applied on the deadman
Madhur Gupta(13118038)
How to avoid deadman zone? 1. 2. 3. 4. 5.
Get coarse and good coke to the hearth Large lump size of central coke (+60 mm) High wind rate and oxygen enrichment Reduced oil rate and possibly increased fuel rate Reduced bottom cooling
For renewal of deadman: cyclic movements of the bed caused by the casting cycle may help in deadman renewal particles that enter the deadman in the centre, descend them deep down into the stagnant bed,and then, with the up-and-down movements of the bed will lead them towards the raceaway. •
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schematic showing deadman coke
How to avoid deadman zone? 1. 2. 3. 4. 5.
Get coarse and good coke to the hearth Large lump size of central coke (+60 mm) High wind rate and oxygen enrichment Reduced oil rate and possibly increased fuel rate Reduced bottom cooling
For renewal of deadman: cyclic movements of the bed caused by the casting cycle may help in deadman renewal particles that enter the deadman in the centre, descend them deep down into the stagnant bed,and then, with the up-and-down movements of the bed will lead them towards the raceaway. •
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schematic showing deadman coke
Abhishek Grover(13118003) ow o measure empera ure an pressure in blast furnace
By Divyansh Gothwal
There is an ongoing effort to reduce pig iron production cost which requires furnace productivity improvement, coke and fuel rate reductions and longer furnace campaign life – often while dealing with poorer raw material quality. To meet the objectives and the limitations, the blast furnace process has to be transparent and it has to be modelled accurately.
ow o measure empera ure an pressure in blast furnace
By Divyansh Gothwal
There is an ongoing effort to reduce pig iron production cost which requires furnace productivity improvement, coke and fuel rate reductions and longer furnace campaign life – often while dealing with poorer raw material quality. To meet the objectives and the limitations, the blast furnace process has to be transparent and it has to be modelled accurately.
Gas flow control in blast furnace
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Rishabh Thakur
Blast furnace is a counter current reactor in which the burden descends as the hot blast gasifies the coke at the tuyeres producing carbon-monoxide which flows upwards heating and reducing the burden materials. This gas is distributed through the coke layers in the cohesive zone and into the granular coke and ore layers. When the burden is charged into the blast furnace, it pushes the coarse coke particles on the top of the coke layer towards the centre . This effect is called the coke push. The optimized gas flow in a modern furnace operated at high productivity and low coke rate has the inverted V shaped melting zone .However the gas escaping through the ore-free centre leaves the furnace with low utilization . This loss of unused gas should be minimised . If the central gas flow is too high, there is a too small gas flow along the wall for heating ,reduction and melting of the ore burden and consequently the root of the melting zone comes close to the tuyeres . In this process the reductant rate will be high and there is high chance of tuyere damage. Therefore it is essential that the gas flowing through the centre distributes itself through the burden layers. Therefore the permeability of the centre coke column must not be too high , which means that the diameter of the central coke column must not be too wide. If the central gas flow is blocked (partially),a relatively large part of the gas escapes along the wall and is cooled down. The result is the part of the gas is cooled down low in the furnace and the reduction reactions slow down. In this situation, the central gas flow is small and heat losses are hig h . Gas flow
Gas flow control in blast furnace
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Rishabh Thakur
Blast furnace is a counter current reactor in which the burden descends as the hot blast gasifies the coke at the tuyeres producing carbon-monoxide which flows upwards heating and reducing the burden materials. This gas is distributed through the coke layers in the cohesive zone and into the granular coke and ore layers. When the burden is charged into the blast furnace, it pushes the coarse coke particles on the top of the coke layer towards the centre . This effect is called the coke push. The optimized gas flow in a modern furnace operated at high productivity and low coke rate has the inverted V shaped melting zone .However the gas escaping through the ore-free centre leaves the furnace with low utilization . This loss of unused gas should be minimised . If the central gas flow is too high, there is a too small gas flow along the wall for heating ,reduction and melting of the ore burden and consequently the root of the melting zone comes close to the tuyeres . In this process the reductant rate will be high and there is high chance of tuyere damage. Therefore it is essential that the gas flowing through the centre distributes itself through the burden layers. Therefore the permeability of the centre coke column must not be too high , which means that the diameter of the central coke column must not be too wide. If the central gas flow is blocked (partially),a relatively large part of the gas escapes along the wall and is cooled down. The result is the part of the gas is cooled down low in the furnace and the reduction reactions slow down. In this situation, the central gas flow is small and heat losses are hig h . Gas flow control is based on keeping the balance between central and wall gas flow to the optimum .
Slag-Hot metal separation •
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The liquid iron and slag collect in the furnace hearth well below the tuyeres .Iron and slag do not mix: slag has a lower specific gravity than hot iron and floats on the iron. The implication of this is that the droplets of iron pass through a layer of slag. Iron and slag come close to thermal and chemical equilibrium. A modern blast furnace has at least two tapholes ,with furnaces as big as 14 m hearth diameter equipped with up to 4 tapholes . The iron is cast into the main runner system or trough . Iron and slag can be separated easily because they do not mix due to difference in their specific gravities . Iron and slag flows through the main trough to a skimmer, which allows the iron to flow through, but diverts the slag to the slag runner .The slag is then usually granulated by water or dumped into slag pits . The
Rishabh Parihar
Slag runners
runner Skimmer plate
TLC
Cast House Layout
Slag-Hot metal separation •
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Rishabh Parihar
The liquid iron and slag collect in the furnace hearth well below the tuyeres .Iron and slag do not mix: slag has a lower specific gravity than hot iron and floats on the iron. The implication of this is that the droplets of iron pass through a layer of slag. Iron and slag come close to thermal and chemical equilibrium. A modern blast furnace has at least two tapholes ,with furnaces as big as 14 m hearth diameter equipped with up to 4 tapholes . The iron is cast into the main runner system or trough . Iron and slag can be separated easily because they do not mix due to difference in their specific gravities . Iron and slag flows through the main trough to a skimmer, which allows the iron to flow through, but diverts the slag to the slag runner .The slag is then usually granulated by water or dumped into slag pits . The iron is collected into torpedo ladle car(TLCs).Two torpedoes are located at each iron runner and can be filled using a tilting runner , which allows the operator to exchange a torpedo during a cast.
Slag runners
runner Skimmer plate
TLC
Cast House Layout
At present Bhilai Steel Plant has 7 blast furnaces and 8 th is under construction. BLAST FURNACE No-> DIMENSION
1,2,3
4,5,6
(Fe~64% size: 10-40mm) 3
Useful Volume (top of the Hearth to stock level)
1033 m
Working Volume (Tuyere to stock level)
886 m3
Full Height , mm No of Tuyeres
Charging Materials Iron ore Lumps
7 3
1719 m
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3
2355 m
Sinter
(Fe~50% Size:5-40mm)
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Coke
1491 m3
(C:75-80% Ash:15-16%)
2105 m3
+
Limestone
(CaO~38%+MgO+SiO2)
+
28750
31250
32350
14
18
24
LD Slag
(CaO + MgO + SiO2)
+
Mn Ore
(Mn:30%min Size:25-80mm)
Installation of a new furnace (BF-8) of capacity 8,030 t/d hot metal production (about 4060 m3 useful volume) at a separate location along with a new stock house and new material handling facilities. BSP's hot metal production is going to reach 7.5 MT per annum by its installation.
+
Quartzite
(SiO2 ~96% Size:25-30mm + Al2O3) +
CDI Coal
(Ash:9-11% FC:56% VM:28%)
Manvendra Singh Lodha: 13118041
At present Bhilai Steel Plant has 7 blast furnaces and 8 th is under construction. BLAST FURNACE No-> DIMENSION
1,2,3
4,5,6
Charging Materials Iron ore Lumps
7
(Fe~64% size: 10-40mm) 3
Useful Volume (top of the Hearth to stock level)
1033 m
Working Volume (Tuyere to stock level)
886 m3
3
1719 m
+
3
2355 m
Sinter
(Fe~50% Size:5-40mm)
+
Coke
1491 m3
(C:75-80% Ash:15-16%)
2105 m3
+
Limestone
(CaO~38%+MgO+SiO2)
+
Full Height , mm No of Tuyeres
28750
31250
32350
14
18
24
LD Slag
(CaO + MgO + SiO2)
+
Mn Ore
(Mn:30%min Size:25-80mm)
Installation of a new furnace (BF-8) of capacity 8,030 t/d hot metal production (about 4060 m3 useful volume) at a separate location along with a new stock house and new material handling facilities. BSP's hot metal production is going to reach 7.5 MT per annum by its installation.
+
Quartzite
(SiO2 ~96% Size:25-30mm + Al2O3) +
CDI Coal
(Ash:9-11% FC:56% VM:28%)
Manvendra Singh Lodha: 13118041
PRODUCTION: Production capacity of Bhilai Steel Plant is 3.153 MT of saleable steel annually. It also specializes in production of other products such as wire rods and merchant products. The main Products of blast furnace are liquid hot metal and the liquid slag which is obtained by dumping iron ore, coke and limestone from the top and preheated air blown into the bottom. Hot Metal : 4.080MT/year Slag volume: Saleable Pig Iron: 0.63MT/year Avg.: 620.00 kg/THM Total Hot Metal Capacity : 4.71 MT / year Range: 521 – 704 kg/THM
COKE CONSUMPTION: Coke consumption is amount(in Kgs) of coke consumed per tonne of hot metal in the Blast Furnace (kg/THM). Coke consumption rate is 450 – 460 Kg/THM which is reduced by achieving maximum CDI rate. Without CDI, coke consumption is 550-650 kg/THM.
Major facilities:3 sintering machines ,7 blast furnaces, coke oven,use of CDI and coal tar ,pellets plant,2 slag granulation plant,2 steel melting shops ,refractory,2 material plant and different mills etc.
MADE BY: NAVEEN KUMAR
ROURKELA STEEL PLANT •
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Rourkela Steel Plant in Rourkela, Odisha is the first integrated steel plant in the public sector in India. It was the first steel plant in Asia to use the LD (Linz-Donawitz) process of steel-making. RSP presently has the capacity to produce 4.5 million tonnes of hot metal, 4.2 million tonnes of crude steel and 3.9 million tonnes of saleable steel. The capacity of Rourkela Steel Plant (RSP) is expected to rise to 10.8 MTPA by 2025.
PRODUCTION: Production capacity of Bhilai Steel Plant is 3.153 MT of saleable steel annually. It also specializes in production of other products such as wire rods and merchant products. The main Products of blast furnace are liquid hot metal and the liquid slag which is obtained by dumping iron ore, coke and limestone from the top and preheated air blown into the bottom. Hot Metal : 4.080MT/year Slag volume: Saleable Pig Iron: 0.63MT/year Avg.: 620.00 kg/THM Total Hot Metal Capacity : 4.71 MT / year Range: 521 – 704 kg/THM
COKE CONSUMPTION: Coke consumption is amount(in Kgs) of coke consumed per tonne of hot metal in the Blast Furnace (kg/THM). Coke consumption rate is 450 – 460 Kg/THM which is reduced by achieving maximum CDI rate. Without CDI, coke consumption is 550-650 kg/THM.
Major facilities:3 sintering machines ,7 blast furnaces, coke oven,use of CDI and coal tar ,pellets plant,2 slag granulation plant,2 steel melting shops ,refractory,2 material plant and different mills etc.
MADE BY: NAVEEN KUMAR
ROURKELA STEEL PLANT •
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Rourkela Steel Plant in Rourkela, Odisha is the first integrated steel plant in the public sector in India. It was the first steel plant in Asia to use the LD (Linz-Donawitz) process of steel-making. RSP presently has the capacity to produce 4.5 million tonnes of hot metal, 4.2 million tonnes of crude steel and 3.9 million tonnes of saleable steel. The capacity of Rourkela Steel Plant (RSP) is expected to rise to 10.8 MTPA by 2025. There exist 5 different blast furnace of which Furnace-1 and Furnace-2 are inactive. Furnance-1 is being re-builded and is expected to complete in 2017. Furnace 5 “Durga” is the biggest blast furnace operating in the country.
Furnace – 3 ,Rourkela Steel Plant •
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Size : Working Volume of the furnace is measured 995 cubic meters where as useful volume is measured 1139 cubic meters. Production : 1200 tonnes per day. Charge Materials : Iron Ore; coke; sinter; Nut coke; Quartzite. Coke consumption : 530 kg per tonne of hot metal. No. of tuyeres : 18
By – Diwakar Panna, En. 13118022
Furnace – 4 ,Rourkela Steel Plant •
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Size : Working Volume of the furnace is measured 1448 cubic meters where as useful volume is measured 1658 cubic meters. Production : 2200 tonnes per day. Charge Materials : Iron Ore; coke; sinter; Nut coke; Quartzite; CDI(Coal Dust Injection) Rate of CDI consumption is 60 kg per tonne of hot metal. Coke consumption : 476 kg per tonne of hot metal. No. of
ROURKELA STEEL PLANT •
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Rourkela Steel Plant in Rourkela, Odisha is the first integrated steel plant in the public sector in India. It was the first steel plant in Asia to use the LD (Linz-Donawitz) process of steel-making. RSP presently has the capacity to produce 4.5 million tonnes of hot metal, 4.2 million tonnes of crude steel and 3.9 million tonnes of saleable steel. The capacity of Rourkela Steel Plant (RSP) is expected to rise to 10.8 MTPA by 2025. There exist 5 different blast furnace of which Furnace-1 and Furnace-2 are inactive. Furnance-1 is being re-builded and is expected to complete in 2017. Furnace 5 “Durga” is the biggest blast furnace operating in the country.
Furnace – 3 ,Rourkela Steel Plant •
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Size : Working Volume of the furnace is measured 995 cubic meters where as useful volume is measured 1139 cubic meters. Production : 1200 tonnes per day. Charge Materials : Iron Ore; coke; sinter; Nut coke; Quartzite. Coke consumption : 530 kg per tonne of hot metal. No. of tuyeres : 18
By – Diwakar Panna, En. 13118022
Furnace – 4 ,Rourkela Steel Plant •
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Size : Working Volume of the furnace is measured 1448 cubic meters where as useful volume is measured 1658 cubic meters. Production : 2200 tonnes per day. Charge Materials : Iron Ore; coke; sinter; Nut coke; Quartzite; CDI(Coal Dust Injection) Rate of CDI consumption is 60 kg per tonne of hot metal. Coke consumption : 476 kg per tonne of hot metal. No. of tuyers : 21
Furnace – 5 ,Rourkela Steel Plant •
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Size : Working Volume of the furnace is measured 3470 cubic meters where as useful volume is measured 4060 cubic meters. Production : 7924 tonnes per day. Charge Materials : Iron Ore; coke; sinter; Nut coke; Quartzite; CDI(Coal Dust Injection); and Pallet (generally used in monsoon season for 2-3 months) Rate of CDI consumption can be maximum 200 kg per tonne of hot metal but average is 150 kg per THM Coke consumption : 400 kg per tonne of hot metal. No. of tuyeres : 36
By – Arpit Agrawal (13118012) JINDAL STEEL PLANT
Founded by O.P. Jindal in 1952. In terms of tonnage, it is the third largest steel producer in India. Leading player in steel, power, mining, oil and gas and infrastructure in India. Products : Rails, Wire Rods, Parallel flange beams and columns, Sponge iron, Mild steel, mild steel slabs, ferro chrome, iron ore, structural, hot rolled plates and coils and coal based sponge iron plant. Steel plants in Chattisgarh, Odisha, Jharkhand. • •
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Furnace – 4 ,Rourkela Steel Plant •
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Size : Working Volume of the furnace is measured 1448 cubic meters where as useful volume is measured 1658 cubic meters. Production : 2200 tonnes per day. Charge Materials : Iron Ore; coke; sinter; Nut coke; Quartzite; CDI(Coal Dust Injection) Rate of CDI consumption is 60 kg per tonne of hot metal. Coke consumption : 476 kg per tonne of hot metal. No. of tuyers : 21
Furnace – 5 ,Rourkela Steel Plant •
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Size : Working Volume of the furnace is measured 3470 cubic meters where as useful volume is measured 4060 cubic meters. Production : 7924 tonnes per day. Charge Materials : Iron Ore; coke; sinter; Nut coke; Quartzite; CDI(Coal Dust Injection); and Pallet (generally used in monsoon season for 2-3 months) Rate of CDI consumption can be maximum 200 kg per tonne of hot metal but average is 150 kg per THM Coke consumption : 400 kg per tonne of hot metal. No. of tuyeres : 36
By – Arpit Agrawal (13118012) JINDAL STEEL PLANT
Founded by O.P. Jindal in 1952. In terms of tonnage, it is the third largest steel producer in India. Leading player in steel, power, mining, oil and gas and infrastructure in India. Products : Rails, Wire Rods, Parallel flange beams and columns, Sponge iron, Mild steel, mild steel slabs, ferro chrome, iron ore, structural, hot rolled plates and coils and coal based sponge iron plant. Steel plants in Chattisgarh, Odisha, Jharkhand. • •
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Jindal Steel And Power Plant Jharkhand (Patratu) 6 MTPA steel plant and a 1320 MW captive power plant (CPP) The wire rod and bar mills are equipped with the latest technology to offer superior quality products like wire rods, TMT, rounds, angles RCS. Blast furnace capacity: 4019 m 3 Basic oxygen furnace of 2 x 200 tonne capacity Plant Facilities: Coke and by-product plant: 1.9 MTPA capacity Sinter plant: 490.5 m 2 capacity Oxygen plant of 2 x 1300 tonnes/day capacity Lime and dolomite calcination plant: 3 x 600 tonnes/day capacity •
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Vertika Bansal 13118104
Chattisgarh Integrated Steel Plant (Raigarh, Tamnar, Raipur) Production Capacity: 3 MTPA steel (world’s largest coal-based sponge iron manufacturing facility at Raigarh) and 1000 MW of thermal power at Tamnar. Charge Material : DRI from DRI plant (1.32 MTPA). Coke consumption is around 0.8 MTPA. No. of tuyers : 30-32 The plant has a Coal-based sponge iron plant, Modern rail and universal beam mill, India's first plate mill and a cement plant. The Jindal Cement plant at Raigarh runs on slag and fly ash. The plant was established to •
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JINDAL STEEL PLANT
Founded by O.P. Jindal in 1952. In terms of tonnage, it is the third largest steel producer in India. Leading player in steel, power, mining, oil and gas and infrastructure in India. Products : Rails, Wire Rods, Parallel flange beams and columns, Sponge iron, Mild steel, mild steel slabs, ferro chrome, iron ore, structural, hot rolled plates and coils and coal based sponge iron plant. Steel plants in Chattisgarh, Odisha, Jharkhand. • •
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Jindal Steel And Power Plant Jharkhand (Patratu) 6 MTPA steel plant and a 1320 MW captive power plant (CPP) The wire rod and bar mills are equipped with the latest technology to offer superior quality products like wire rods, TMT, rounds, angles RCS. Blast furnace capacity: 4019 m 3 Basic oxygen furnace of 2 x 200 tonne capacity Plant Facilities: Coke and by-product plant: 1.9 MTPA capacity Sinter plant: 490.5 m 2 capacity Oxygen plant of 2 x 1300 tonnes/day capacity Lime and dolomite calcination plant: 3 x 600 tonnes/day capacity •
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Vertika Bansal 13118104
Chattisgarh Integrated Steel Plant (Raigarh, Tamnar, Raipur) Production Capacity: 3 MTPA steel (world’s largest coal-based sponge iron manufacturing facility at Raigarh) and 1000 MW of thermal power at Tamnar. Charge Material : DRI from DRI plant (1.32 MTPA). Coke consumption is around 0.8 MTPA. No. of tuyers : 30-32 The plant has a Coal-based sponge iron plant, Modern rail and universal beam mill, India's first plate mill and a cement plant. The Jindal Cement plant at Raigarh runs on slag and fly ash. The plant was established to manage solid waste generated from steel and power plants and to process them into cement (known as Portland Slag Cement). •
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Odisha Proposed Integrated Steel Plant (Angul, Barbil and Tensa)
Production Capacity: 12.5 MTPA steel and 2500 MW of power(Angul).The pellet plant at Barbil has a total capacity of 9 MTPA. The iron ore mine at Tensa produces 3.11 MTPA sponge grade iron ore. Coal gasification plant to produce 225,000 nm3/hr of syn gas. Technology : DRI-BF-EAF route would be adopted for steel production. Has a unique feature of using syn gas from the coal gasification plants as reductant. Used for first time in the world and has the advantage of using high ash coal. Major Facilities include : Coal washery, Sinter plant, Pellet plant, coke oven and byproduct plant, coal gasification plant, DRI plant ,BF, Steel Melting Shop, Power plant. •
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Pallavi Jha 13118052
TISCO Jamshedpur ,Jharkhand The plant was built up by the famous industrialist J.N. Tata in 1907 where the production of pig iron was started in 1908 and of steel in 1911. It is the second largest and the only private sector steel plant in the country
Chattisgarh Integrated Steel Plant (Raigarh, Tamnar, Raipur) Production Capacity: 3 MTPA steel (world’s largest coal-based sponge iron manufacturing facility at Raigarh) and 1000 MW of thermal power at Tamnar. Charge Material : DRI from DRI plant (1.32 MTPA). Coke consumption is around 0.8 MTPA. No. of tuyers : 30-32 The plant has a Coal-based sponge iron plant, Modern rail and universal beam mill, India's first plate mill and a cement plant. The Jindal Cement plant at Raigarh runs on slag and fly ash. The plant was established to manage solid waste generated from steel and power plants and to process them into cement (known as Portland Slag Cement). •
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Odisha Proposed Integrated Steel Plant (Angul, Barbil and Tensa)
Production Capacity: 12.5 MTPA steel and 2500 MW of power(Angul).The pellet plant at Barbil has a total capacity of 9 MTPA. The iron ore mine at Tensa produces 3.11 MTPA sponge grade iron ore. Coal gasification plant to produce 225,000 nm3/hr of syn gas. Technology : DRI-BF-EAF route would be adopted for steel production. Has a unique feature of using syn gas from the coal gasification plants as reductant. Used for first time in the world and has the advantage of using high ash coal. Major Facilities include : Coal washery, Sinter plant, Pellet plant, coke oven and byproduct plant, coal gasification plant, DRI plant ,BF, Steel Melting Shop, Power plant. •
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Pallavi Jha 13118052
TISCO Jamshedpur ,Jharkhand The plant was built up by the famous industrialist J.N. Tata in 1907 where the production of pig iron was started in 1908 and of steel in 1911. It is the second largest and the only private sector steel plant in the country
Description-The plant has basic open hearth furnaces, acid Bessemer conveners and basic tilting open hearth furnaces for the manufacture of pig iron and steel. With the help of electric furnaces it is making high grade carbon steel which is used for structural fit-tings and tin plates. Products-Railway wheels, tires and axles, bars, rods, sheets, corrugated sheets, wires, steel castings, nails, nuts, bolts and tinplates. Special alloy steel produced by the plant is used for making bullet-proof armor plates and for armor-piercing bullets.
Power consumtion- 3,494.30 M.KWH By: Rakesh Meena 13118068
Jharkhand Integrated Steel Plant (Jamshedpur)
Production Capacity (per annum):1.9 million tones of pig iron, 2 million tones of ingot steel and 3 million tones of saleable steel No of blast furnaces- 9(A-I) Volume of blast furnace(avg)- 4000 cubic meter Avg Capacity of B.F.- 2.4 mtpa to 3.15 mtpa Charge Material(per annum)- 27.45 lakh tones of iron ore,24.45 lakh
TISCO Jamshedpur ,Jharkhand The plant was built up by the famous industrialist J.N. Tata in 1907 where the production of pig iron was started in 1908 and of steel in 1911. It is the second largest and the only private sector steel plant in the country
Description-The plant has basic open hearth furnaces, acid Bessemer conveners and basic tilting open hearth furnaces for the manufacture of pig iron and steel. With the help of electric furnaces it is making high grade carbon steel which is used for structural fit-tings and tin plates. Products-Railway wheels, tires and axles, bars, rods, sheets, corrugated sheets, wires, steel castings, nails, nuts, bolts and tinplates. Special alloy steel produced by the plant is used for making bullet-proof armor plates and for armor-piercing bullets.
Power consumtion- 3,494.30 M.KWH By: Rakesh Meena 13118068
Jharkhand Integrated Steel Plant (Jamshedpur)
Production Capacity (per annum):1.9 million tones of pig iron, 2 million tones of ingot steel and 3 million tones of saleable steel No of blast furnaces- 9(A-I) Volume of blast furnace(avg)- 4000 cubic meter Avg Capacity of B.F.- 2.4 mtpa to 3.15 mtpa Charge Material(per annum)- 27.45 lakh tones of iron ore,24.45 lakh tones of coal,5 lakh tones of limestone,2.62 lakh tones of dolomite, 90,000 tones of manganese and Ferro-manganese, and 40,000 tones of quartzite. Coke consumption:24.45 lakhs tones per annum No. of tuyeres : 30-32
Proposed Integrated Steel Plant •
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A 6 MTPA capacity plant in Kalinganagar, Odisha, India. An expansion of the capacity of its plant in Jharkhand from 6.8 to 10 million tones per annum. 5 MTPA capacity plant in Chhattisgarh, India . By: Pritish Topno:13118064
Jharkhand Integrated Steel Plant (Jamshedpur)
Production Capacity (per annum):1.9 million tones of pig iron, 2 million tones of ingot steel and 3 million tones of saleable steel No of blast furnaces- 9(A-I) Volume of blast furnace(avg)- 4000 cubic meter Avg Capacity of B.F.- 2.4 mtpa to 3.15 mtpa Charge Material(per annum)- 27.45 lakh tones of iron ore,24.45 lakh tones of coal,5 lakh tones of limestone,2.62 lakh tones of dolomite, 90,000 tones of manganese and Ferro-manganese, and 40,000 tones of quartzite. Coke consumption:24.45 lakhs tones per annum No. of tuyeres : 30-32
Proposed Integrated Steel Plant •
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A 6 MTPA capacity plant in Kalinganagar, Odisha, India. An expansion of the capacity of its plant in Jharkhand from 6.8 to 10 million tones per annum. 5 MTPA capacity plant in Chhattisgarh, India . By: Pritish Topno:13118064
1.Coaking Coal and Non-Coking Coal 2.Coal to coke process and by-produ cts in co ke oven plant 3.Impurities in coal and how to remove 4.Speciality about Australian -New Zealand coal and w eathering effect
Presented b y: Brajesh kumar Harish Parihar Pulkit Khandelw al Shubhankar Rajpo ot Shreya Ankit Kumar Anuj Agarw al
1.Coaking Coal and Non-Coking Coal 2.Coal to coke process and by-produ cts in co ke oven plant 3.Impurities in coal and how to remove 4.Speciality about Australian -New Zealand coal and w eathering effect
Presented b y: Brajesh kumar Harish Parihar Pulkit Khandelw al Shubhankar Rajpo ot Shreya Ankit Kumar Anuj Agarw al
Used in manufacturing steel, where carbon mu st be as volatile-free and ash-free as possib le.
Coking coal is also h eated to pr oduc e coke, a hard p orou s material which is used to blast in fu rnaces for t he extraction of ir on from the iron o re.
Coking coal is con verted to c oke by drivin g of f impu rities to leave almost pure carbon.
The physi cal properti es of co king c oal cause the coal to soften, liquefy and then re-solidify i nto hard but porous lumps w hen heated in the absence of air.
The coking pr ocess consist s of heating coki ng coal to around 10001100C in the absence of oxygen t o drive off the volatile compo unds . This pro cess results in a hard poro us material - coke.
Used in manufacturing steel, where carbon mu st be as volatile-free and ash-free as possib le.
Coking coal is also h eated to pr oduc e coke, a hard p orou s material which is used to blast in fu rnaces for t he extraction of ir on from the iron o re.
Coking coal is con verted to c oke by drivin g of f impu rities to leave almost pure carbon.
The physi cal properti es of co king c oal cause the coal to soften, liquefy and then re-solidify i nto hard but porous lumps w hen heated in the absence of air.
The coking pr ocess consist s of heating coki ng coal to around 10001100C in the absence of oxygen t o drive off the volatile compo unds . This pro cess results in a hard poro us material - coke.
Coke is produc ed in a coke battery which is c ompo sed of many coke ovens st acked in rows i nto w hich coal is loaded. Harish Parihar
No c oking properties.
Mainly used as thermal coal for pow er generation .
Has a higher ash content.
Used in industr ies like cement, fertilizer, glass, ceramic, p aper, chemical and bric k manufacturing.
Indian Non Coking Coal is classified on the basis of Gross Calorific Value (GCV) which
No c oking properties.
Mainly used as thermal coal for pow er generation .
Has a higher ash content.
Used in industr ies like cement, fertilizer, glass, ceramic, p aper, chemical and bric k manufacturing.
Indian Non Coking Coal is classified on the basis of Gross Calorific Value (GCV) which consist s of 17 GCV bands
Brajesh Kumar
This Conversion can be easil y Comprehended by an Understandi ng of These Zones Different Temperature Zones for Transformation of Coal to Coke : 1. 375 *C-475 *C - Coal decomposes to fo rm Plastic Layer 2. 475 *C-600 *C - Marked Evolution of Tar and Aromatic Compou nds and Hydro-Carbons 3. 600*C-1100*C – Coke Stabili zation Phase Now this Incandescent Coke is pu shed fro m the Oven and th en Wet
This Conversion can be easil y Comprehended by an Understandi ng of These Zones Different Temperature Zones for Transformation of Coal to Coke : 1. 375 *C-475 *C - Coal decomposes to fo rm Plastic Layer 2. 475 *C-600 *C - Marked Evolution of Tar and Aromatic Compou nds and Hydro-Carbons 3. 600*C-1100*C – Coke Stabili zation Phase Now this Incandescent Coke is pu shed fro m the Oven and th en Wet or Dry Quenched prio r to it s shi pment to B last-Furnace.
Figure : Incandescent coke in the oven waiting to be "pushed".
Pulkit
- Saturated raw gas coming from t he coke oven battery con tains around 46 % to 48 % water vapour. - Raw cok e oven gas also con tains various c ontaminants, which give coke oven gas its un ique characteristics . These cons ist of 1. Tar components 2. Tar acid gases (phenolic gases) 3. Tar base gases (pyridine bases) 4. Benzene, toluene and xylene (BTX), lig ht oil and other aromatics 5. Naphthalene 6. Ammoni a gas 7. Hydrog en sulfi de gas 8. Hydrog en cyanide gas 9 Ammonium chloride
- Saturated raw gas coming from t he coke oven battery con tains around 46 % to 48 % water vapour. - Raw cok e oven gas also con tains various c ontaminants, which give coke oven gas its un ique characteristics . These cons ist of 1. Tar components 2. Tar acid gases (phenolic gases) 3. Tar base gases (pyridine bases) 4. Benzene, toluene and xylene (BTX), lig ht oil and other aromatics 5. Naphthalene 6. Ammoni a gas 7. Hydrog en sulfi de gas 8. Hydrog en cyanide gas 9. Ammonium chloride 10. Carbon di sulp hide
Shubhankar
To determine the nature of coal, tw o types of analys is are don e: Proximate Analysi s : determines moi sture content , volatil e matter ,fixed carbon and ash. Ultimate Analysi s :determines amount of carbon, hydrogen , oxygen ,nitro gen and sulphur
Proximate Analysis of Indian Coal Carboncontent
25%
Ash 52%
Volatile Material 18%
Moisture 2%
Ultimate analysis of Indian Coal
Ash
C 31%
H
In coal , ash contains many elements such as sodium ,potassium, sulphur
To determine the nature of coal, tw o types of analys is are don e: Proximate Analysi s : determines moi sture content , volatil e matter ,fixed carbon and ash. Ultimate Analysi s :determines amount of carbon, hydrogen , oxygen ,nitro gen and sulphur
Proximate Analysis of Indian Coal Carboncontent
25%
Ash 52%
Volatile Material 18%
Moisture 2%
Ultimate analysis of Indian Coal
Ash 52%
C 31% S O 8% 7%
H 2% N 0.1%
In coal , ash contains many elements such as sodium ,potassium, sulphur , magnesium , titanium , alumin ium and sili con.
shreya
Coal Properties can be improv ed by removal of i mpurit ies. Removal of imp urities is generally c alled Coal Benefic iation ,Coal Preparatio n or Coal Washing .
Two basic processes of benefici ation are: Dry-deshaling: Non-coal or shaly-coal is removed wit hout using any liqui d media.It is cheaper than wet process. Separatio ns at relatively hig h densit ies is referred to as ‘deshaling ’. Wet Process: Coal is crus hed to smaller size and put in a liquid media of adju stable specifi c gravity to separate the lighter coal (low ash) from heavier coal (hig h ash). The rejects fro m wet proc ess also cont ain carbonaceous matter.
After all the abo ve pro cess es , the coal obtained would have much
Coal Properties can be improv ed by removal of i mpurit ies. Removal of imp urities is generally c alled Coal Benefic iation ,Coal Preparatio n or Coal Washing .
Two basic processes of benefici ation are: Dry-deshaling: Non-coal or shaly-coal is removed wit hout using any liqui d media.It is cheaper than wet process. Separatio ns at relatively hig h densit ies is referred to as ‘deshaling ’. Wet Process: Coal is crus hed to smaller size and put in a liquid media of adju stable specifi c gravity to separate the lighter coal (low ash) from heavier coal (hig h ash). The rejects fro m wet proc ess also cont ain carbonaceous matter.
After all the abo ve pro cess es , the coal obtained would have much less ash con tent and also th e percentage of c arbon w ould i ncrease.
shreya
Australian Coal • Australia is the world's second largest coal exporter, as it exports roughly 73% of its coal production • Mostly high-quality bituminous coal (black coal) is found • Australia can supply the full range of metallurgical coals. These include traditional products such as hard and soft coking coals as well as lower grade metallurgical coals such as semi-soft coking and PCI coals. • Australian coals have good coking
New Zealand Coal • 44 % of total coal produced in New Zealand is exported • Over 80% of the reserves are lignite( brown coal) • Specification: • Low Sulphur • Low to medium volatile matter • Low inherent moisture • Low iron • High swell • High vitrinite content
Australian Coal • Australia is the world's second largest coal exporter, as it exports roughly 73% of its coal production • Mostly high-quality bituminous coal (black coal) is found • Australia can supply the full range of metallurgical coals. These include traditional products such as hard and soft coking coals as well as lower grade metallurgical coals such as semi-soft coking and PCI coals. • Australian coals have good coking properties and are generally low in Sulphur (0.3 to 0.8 per cent) and many are low in phosphorus.
New Zealand Coal • 44 % of total coal produced in New Zealand is exported • Over 80% of the reserves are lignite( brown coal) • Specification: • Low Sulphur • Low to medium volatile matter • Low inherent moisture • Low iron • High swell • High vitrinite content
Ankit Kumar
Distu isturb rba ance nce to the the wate waterr-sa satu tura rate ted, d, oxyg ox yge en-fr n-fre ee enviro nvironm nme ent of coa coal (befo before re mini mi ning ng)) ,such such as a c ha han g e i n t he he t em em pe per at at ur ur e, e, m oi oi st st ur ur e c on on te ten t o r o xy xy g en en p ar ar ti ti al al p re res su su re re, w iill l af fe fec t t he he coa coal’s l’s phys physica icall and chemic chemica al stabil stability ity.. Th i s d yn yn am ic ic b eh eh av i ou ou r o f c o al i s t er me med ‘ w ea eat h er in in g ’ an d i n cl cl u d es t h e aer ia ial o x id id at io io n o f t h e o r g an i c an d m i n er al m at t er (c h em ic ic al w ea eat h er i ng ng ), t h e m ic ic r o b i al o x i d at i o n o f p y r it it e (biologica biological weathe weathering) ring) an d c ha han g es i n t h e m oi oi s tu tu r e c on on t en t t h at m ay ay r es es u l t i n p ar ti ti c le le s iz ize d eg r ad ad at i on on (p h ys ys ic i c al weathering) PROPERTY EFFECTS FROTH FLOTATION
The effectiveness of processes such as froth flotation and oil agglomeration is largely reduced.
CALORIFIC VALUE
Calorific Value Value decreases. decreases. High rank coals may be only slightly slightly affected, whereas in low rank coals the effects may be severe.
COKING PROPERTIES
Decreases Decreases : The “coking value” of coal is likely likely to be destroyed destroyed after a period of 3 years. Coke reactivity also increases when weathered coal is used and this is detrimental to the operation of blast furnaces.
Distu isturb rba ance nce to the the wate waterr-sa satu tura rate ted, d, oxyg ox yge en-fr n-fre ee enviro nvironm nme ent of coa coal (befo before re mini mi ning ng)) ,such such as a c ha han g e i n t he he t em em pe per at at ur ur e, e, m oi oi st st ur ur e c on on te ten t o r o xy xy g en en p ar ar ti ti al al p re res su su re re, w iill l af fe fec t t he he coa coal’s l’s phys physica icall and chemic chemica al stabil stability ity.. Th i s d yn yn am ic ic b eh eh av i ou ou r o f c o al i s t er me med ‘ w ea eat h er in in g ’ an d i n cl cl u d es t h e aer ia ial o x id id at io io n o f t h e o r g an i c an d m i n er al m at t er (c h em ic ic al w ea eat h er i ng ng ), t h e m ic ic r o b i al o x i d at i o n o f p y r it it e (biologica biological weathe weathering) ring) an d c ha han g es i n t h e m oi oi s tu tu r e c on on t en t t h at m ay ay r es es u l t i n p ar ti ti c le le s iz ize d eg r ad ad at i on on (p h ys ys ic i c al weathering) PROPERTY EFFECTS FROTH FLOTATION
The effectiveness of processes such as froth flotation and oil agglomeration is largely reduced.
CALORIFIC VALUE
Calorific Value Value decreases. decreases. High rank coals may be only slightly slightly affected, whereas in low rank coals the effects may be severe.
COKING PROPERTIES
Decreases Decreases : The “coking value” of coal is likely likely to be destroyed destroyed after a period of 3 years. Coke reactivity also increases when weathered coal is used and this is detrimental to the operation of blast furnaces.
SULPHUR CONTENT
Total sulphur in coal decreases with increased weathering. This is due to sulphate sulphur being leached from the coal.
MOISTURE CONTENT
Inherent moisture content decreases decreases
VOLA VOLATI TILE LE CONT CONTENT ENT
Decreases
Anu An u j Ag A g arw al
Furnaces Group -12
Furnaces Group -12
Group members Alisha Alisha Anil Manwa Manwarr 13120012 13120012 Amandeep Amandeep Singh 13118006 13118006 Anu Garg Garg 1321400 13214004 4 Divyanshu Gupta 13118021 Ravi Ravi Raj Raj 1311 131180 8071 71 Satyendra Satyendra Kumar Tiwari 13121021 Seth Seth Riddhe Riddheis ish h Anil Anilku kuma marr 1311 131180 8080 80 Shubham Jain, 13118089 13118089 .
Group members Alisha Alisha Anil Manwa Manwarr 13120012 13120012 Amandeep Amandeep Singh 13118006 13118006 Anu Garg Garg 1321400 13214004 4 Divyanshu Gupta 13118021 Ravi Ravi Raj Raj 1311 131180 8071 71 Satyendra Satyendra Kumar Tiwari 13121021 Seth Seth Riddhe Riddheis ish h Anil Anilku kuma marr 1311 131180 8080 80 Shubham Jain, 13118089 13118089 .
Rotary Kiln -Introduction
Rotary kiln refers to rotary calciner, belongs to building material equipment. It can be divided into cement rotary kiln, metallurgy rotary kiln and lime rotary kiln. Rotary Kiln- Working Principle
Rotary kiln is made of steel plate, and inside the kiln body inserts refractory lining, which keeps specified inclination with horizontal line. Rotary kilns are used to heat solids to a predetermined temperature in order to create a chemical and/or physical reaction. The two basic types of rotary kilns – direct fired and indirect fired .
Material is fed into kiln from kiln tail. Due to the slope and rotation of the cylinder, the material make a composite motion—it rolls in circumferential direction and at the same time moves in axial direction. After sintering process, the material is calcined in cement clinker and discharged into cooler machine through kiln head hood, prayed into the kiln from the kiln head, the fuel burns in the kiln, after exchanging with the material, the generated
Rotary Kiln -Introduction
Rotary kiln refers to rotary calciner, belongs to building material equipment. It can be divided into cement rotary kiln, metallurgy rotary kiln and lime rotary kiln. Rotary Kiln- Working Principle
Rotary kiln is made of steel plate, and inside the kiln body inserts refractory lining, which keeps specified inclination with horizontal line. Rotary kilns are used to heat solids to a predetermined temperature in order to create a chemical and/or physical reaction. The two basic types of rotary kilns – direct fired and indirect fired .
Material is fed into kiln from kiln tail. Due to the slope and rotation of the cylinder, the material make a composite motion—it rolls in circumferential direction and at the same time moves in axial direction. After sintering process, the material is calcined in cement clinker and discharged into cooler machine through kiln head hood, prayed into the kiln from the kiln head, the fuel burns in the kiln, after exchanging with the material, the generated waste is discharged from kiln tail. The burner in this design is excluding fuel
ROTARY KILN PROCESSES Torrefication, Pyrolysis (Thermolysis), Carbonisation, Gasification, LTC (Low Temperature Conversion),Calcination, Drying, Cooling. Anu Garg 13214004 •
TYPES OF ROTARY KILNS
NOVEL APPROACH
USAGE OF ROTARY KILN FOR TYPE 1: Counter current rotary kiln; TYPE 2: Co-current rotary kiln RECLAIMING NICKEL BY FEECO By using rotary kilns to generate COUNTER CURRENT ROTARY COCURRENT ROTARY KILN high processing KILN 1.Flue gases flow in the same temperatures, FEECO created an 1.Flue gases flow in the direction of the waste, with innovative recycling method that opposite direction of the the inclination of the kiln. eliminated unnecessary organic waste, against the inclination material while recovering valuable of the kiln. minerals. The customer was able to 2. Mass reduction (%) > 86 %. 2. Mass reduction (%) > 76 %. reclaim nickel from waste 3. Fly ashes:760 mg/Nm3. 3. Fly ashes:1700 mg/Nm3. materials, prevent toxic materials from entering the environment, and promote a sustainable and profitable material solution. •
Advantages:
1. The rotary kiln has the function of the heat exchanger. The rotary kiln has the homogenous temperature field. 2 The installation of the excellent combustion apparatus can ensure the full combustion of the fuel,. 3. With the different needs of cement clinker minerals in the different stages, it can not only meet the heat exchange and temperature requirements of different minerals in different stages, but also can meet
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NOVEL APPROACH
TYPES OF ROTARY KILNS
USAGE OF ROTARY KILN FOR TYPE 1: Counter current rotary kiln; TYPE 2: Co-current rotary kiln RECLAIMING NICKEL BY FEECO By using rotary kilns to generate COUNTER CURRENT ROTARY COCURRENT ROTARY KILN high processing KILN 1.Flue gases flow in the same temperatures, FEECO created an 1.Flue gases flow in the direction of the waste, with innovative recycling method that opposite direction of the the inclination of the kiln. eliminated unnecessary organic waste, against the inclination material while recovering valuable of the kiln. minerals. The customer was able to 2. Mass reduction (%) > 86 %. 2. Mass reduction (%) > 76 %. reclaim nickel from waste 3. Fly ashes:760 mg/Nm3. 3. Fly ashes:1700 mg/Nm3. materials, prevent toxic materials from entering the environment, and promote a sustainable and profitable material solution. •
Advantages:
1. The rotary kiln has the function of the heat exchanger. The rotary kiln has the homogenous temperature field. 2 The installation of the excellent combustion apparatus can ensure the full combustion of the fuel,. 3. With the different needs of cement clinker minerals in the different stages, it can not only meet the heat exchange and temperature requirements of different minerals in different stages, but also can meet their requirements on time. 4. Because the rotary kiln has high temperature field and thermal field stagnation air time long, biodegradable chemical, pharmaceutical, etc discharge of poisonous and harmful waste.
ALISHA ANIL MANWAR 13120012 Structure and principle-It is a vertical refractory lined cylinder in which a fixed bed or descending column of solids is maintained ,and through which an ascending stream of hot gas is forced .The shaft furnace works on counter current principle where the iron ore feed material moves downward in the furnace by gravity and gets reduced by the up flowing reducing gases. Notable examples- pig iron blast furnace, phosphorous(from phosphate rock) furnace. Types- Shaft furnaces can either be static or tilt able (tilting model, where the shaft is static is possible too). Operation based on principle-Moderate velocities of the gaseous combustion products are characteristic of shaft furnace. The bulk of the lumped materials(the charge) s not entrained by the ascending gas stream and, in contrast to the fluidised bed furnace, maintains aerodynamic stability. The counter-current motion of the charge (top to bottom) and of the gases forced through the charge(bottom to top) and the direct contact between the charge and hot gases result in good heat exchange and generation of low temperature exhaust gases. Consequently, shaft furnaces are characterized by a high thermal efficiency and a relatively high output. So such furnaces are widely used to smelt iron ores and in non-ferrous metallurgy of Ca,Ni etc. Parts of Simplified Shaft furnace shown alongside: (1) charging device (2)gas outlet (3)Tuyere (4)outside crucible
Structure and principle-It is a vertical refractory lined cylinder in which a fixed bed or descending column of solids is maintained ,and through which an ascending stream of hot gas is forced .The shaft furnace works on counter current principle where the iron ore feed material moves downward in the furnace by gravity and gets reduced by the up flowing reducing gases. Notable examples- pig iron blast furnace, phosphorous(from phosphate rock) furnace. Types- Shaft furnaces can either be static or tilt able (tilting model, where the shaft is static is possible too). Operation based on principle-Moderate velocities of the gaseous combustion products are characteristic of shaft furnace. The bulk of the lumped materials(the charge) s not entrained by the ascending gas stream and, in contrast to the fluidised bed furnace, maintains aerodynamic stability. The counter-current motion of the charge (top to bottom) and of the gases forced through the charge(bottom to top) and the direct contact between the charge and hot gases result in good heat exchange and generation of low temperature exhaust gases. Consequently, shaft furnaces are characterized by a high thermal efficiency and a relatively high output. So such furnaces are widely used to smelt iron ores and in non-ferrous metallurgy of Ca,Ni etc. Parts of Simplified Shaft furnace shown alongside: (1) charging device (2)gas outlet (3)Tuyere (4)outside crucible (5)slag notch (6) matte hole (7) inside crucible -Seth Riddheish Anilkumar , 13118080
Can be designed for non-ferrous material like Ni, Al and for non metals like P.
Longer lifetime than other furnaces
Applicable for different scrap qualities
Advantages of Shaft Furnace Fast and continuous melting
EXAMPLES :-
Slag can easily be tapped out
Optimized thermal efficiency with atleast 40% lower energy consumption than other furnace.
1. Pig Iron Blast furnace 2. Cupolas (A cupola or cupola furnace is a melting device used in foundries that can be used to melt cast iron. The cupola can be made almost any practical size). 3. Aluminium shaft melting furnaces (Shaft geometry and especially adapted burner technology process steps such as preheating, heating and liquefaction can be combined in one melting shaft. The molten material is added in a cold state in the shaft, sinks down the
Can be designed for non-ferrous material like Ni, Al and for non metals like P.
Longer lifetime than other furnaces
Applicable for different scrap qualities
Advantages of Shaft Furnace Fast and continuous melting
Slag can easily be tapped out
EXAMPLES :-
Optimized thermal efficiency with atleast 40% lower energy consumption than other furnace.
1. Pig Iron Blast furnace 2. Cupolas (A cupola or cupola furnace is a melting device used in foundries that can be used to melt cast iron. The cupola can be made almost any practical size). 3. Aluminium shaft melting furnaces (Shaft geometry and especially adapted burner technology process steps such as preheating, heating and liquefaction can be combined in one melting shaft. The molten material is added in a cold state in the shaft, sinks down the shaft and is heated up during sinking. Ascending flue gasses resulting from the melting process are cooled, i.e. the shaft furnace functions in a favorable counter flow principle relating to warmth. The molten material flows without turbulences and dross to holding room where the selected tapping temperature is maintained). -Shubham Jain, 13118089
Rotary Hearth Furnace : Principle and Working : The RHF consists of a flat, refractory hearth rotating inside a stationary, circular tunnel kiln. Inside the RHF, direct reduction of iron ore or iron-bearing byproducts occurs, using coal as the reductant. The feed to the RHF consists of composite agglomerates made from a mixture of iron oxides (virgin ore or by-products) and a carbon source such as coal, BF dust, charcoal or other carbon-bearing solid. The temperature is controlled by means of burners positioned along the walls and roof of furnace .For optimized heating quality the annular furnace peripherically divide into several temperature control zones : The Preheating zone , Heating zone and uniform heating zone Hearth and reducing gas rotate in opposite •
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Sketch of Rotary Hearth Furnace
Rotary Hearth Furnace : Principle and Working : The RHF consists of a flat, refractory hearth rotating inside a stationary, circular tunnel kiln. Inside the RHF, direct reduction of iron ore or iron-bearing byproducts occurs, using coal as the reductant. The feed to the RHF consists of composite agglomerates made from a mixture of iron oxides (virgin ore or by-products) and a carbon source such as coal, BF dust, charcoal or other carbon-bearing solid. The temperature is controlled by means of burners positioned along the walls and roof of furnace .For optimized heating quality the annular furnace peripherically divide into several temperature control zones : The Preheating zone , Heating zone and uniform heating zone Hearth and reducing gas rotate in opposite direction to reduce pellets / briquettes to metallic Iron at temperature around 1300 c . •
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Sketch of Rotary Hearth Furnace
Satyendra Kumar Tiwari 13121021
ADVANTAGES : Production of DRI(Direct Reduced Iron). Carbon source can be coal, coke fines, charcoal, or other carbon-bearing solid. Work flexibility and high reliability. High temperature uniformity :Suitable for heat treating large quantities of the same parts. Furnace atmosphere easy to control and High superheating power . Overpressure control . Economical and Safe operations : Low consumption of technological mediums . Easy service and maintenance. High quality parts : no scale and decarburization .High repeatability of processes : Fully automated and quick loading and unloading of the load .Used for various treatment processes such as case hardening and carburizing (low case depth), neutral hardening, reheating, tempering, annealing etc. EXAMPLES : FASTMET : Coal-based iron oxide reduction process. Uses a rotary hearth furnace to convert steel mill wastes and iron oxide fines to highly metallized DRI. Extremely energy efficient. FASTMELT : Uses a rotary hearth furnace but adds an electric iron melting furnace for production of a high quality hot metal known as FASTIRON . Can convert poor quality iron ores and non-coking coals into quality pig iron products. FASTEEL : More environmentally friendly as merging of the hot metal producing benefits of FASTMELT with the continuous scrap feeding and preheating of CONSTEEL to produce high quality steel.
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ADVANTAGES : Production of DRI(Direct Reduced Iron). Carbon source can be coal, coke fines, charcoal, or other carbon-bearing solid. Work flexibility and high reliability. High temperature uniformity :Suitable for heat treating large quantities of the same parts. Furnace atmosphere easy to control and High superheating power . Overpressure control . Economical and Safe operations : Low consumption of technological mediums . Easy service and maintenance. High quality parts : no scale and decarburization .High repeatability of processes : Fully automated and quick loading and unloading of the load .Used for various treatment processes such as case hardening and carburizing (low case depth), neutral hardening, reheating, tempering, annealing etc. EXAMPLES : FASTMET : Coal-based iron oxide reduction process. Uses a rotary hearth furnace to convert steel mill wastes and iron oxide fines to highly metallized DRI. Extremely energy efficient. FASTMELT : Uses a rotary hearth furnace but adds an electric iron melting furnace for production of a high quality hot metal known as FASTIRON . Can convert poor quality iron ores and non-coking coals into quality pig iron products. FASTEEL : More environmentally friendly as merging of the hot metal producing benefits of FASTMELT with the continuous scrap feeding and preheating of CONSTEEL to produce high quality steel. FASTOx : High quality steelmaking for areas without economic scrap supplies, or clients with pre-existing BOF equipment . Can use locally available iron ore fines and non coking coals, coke fines, or charcoal. ITmk3 : Processing iron ore fines into almost pure pig iron nuggets in only ten minutes. Supply pig iron grade nuggets directly to the EAF steelmaking industry.
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Amandeep Singh 13118006 MT-1
Fluidized Bed •
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Essentially consists of a main column in which the iron ore –coal mixture is fluidized at high velocity and a return column in which the entrained entrained solids from the main column are collected via a cyclone. Solids from the return column are re-circulated to the bottom of the bed in the main column through a control valve. Fast bed conditions prevail prevail in the main column and the solids in the return column constitute the slow bed. Solids are continuously fed in at the top of the reactor and enter the slow bed through the cyclone. During this descent, the solids get preheated preheated by the rising gases. Partial reduction of the higher hig her oxides of iron also takes place. The fluidized bed reactor operates operates at 400- 450 C temp. and 46 atm pressure. High High pressure pressure is required required to produce produce non sticky and un-sintered iron powder and increase reactio reaction n rate. rate. Conversion Conversion of iron oxide oxide – 98% Hydrogen Hydrogen utilization – 5% thus necessating recirculation of exit gas after drying. Highly pyrophr pyrophric ic iron prod product uct is treate treated d with N2 N2 at 8181- - 870C before storing Applications in powder metallurgical and briquetting industries. Typical Typical dimensions of 50 tpa tpa rector: 1.7m OD and 29m 29m height. Approx Approx .051 - .056 ton of H2 and .25 ton ton of O2 reqd. to process process 1.4 ton of high grade magnetite to arrive at 1 ton of iron Reaction aspects:
Schematic diagram of circulating fluidized bed reactor
Generation of gaseous reductants
Fluidized Bed •
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Essentially consists of a main column in which the iron ore –coal mixture is fluidized at high velocity and a return column in which the entrained entrained solids from the main column are collected via a cyclone. Solids from the return column are re-circulated to the bottom of the bed in the main column through a control valve. Fast bed conditions prevail prevail in the main column and the solids in the return column constitute the slow bed. Solids are continuously fed in at the top of the reactor and enter the slow bed through the cyclone. During this descent, the solids get preheated preheated by the rising gases. Partial reduction of the higher hig her oxides of iron also takes place. The fluidized bed reactor operates operates at 400- 450 C temp. and 46 atm pressure. High High pressure pressure is required required to produce produce non sticky and un-sintered iron powder and increase reactio reaction n rate. rate. Conversion Conversion of iron oxide oxide – 98% Hydrogen Hydrogen utilization – 5% thus necessating recirculation of exit gas after drying. Highly pyrophr pyrophric ic iron prod product uct is treate treated d with N2 N2 at 8181- - 870C before storing Applications in powder metallurgical and briquetting industries. Typical Typical dimensions of 50 tpa tpa rector: 1.7m OD and 29m 29m height. Approx Approx .051 - .056 ton of H2 and .25 ton ton of O2 reqd. to process process 1.4 ton of high grade magnetite to arrive at 1 ton of iron Reaction aspects:
Schematic diagram of circulating fluidized bed reactor
Generation of gaseous reductants
For reduction of iron oxide
Divyanshu Gupt 13118021
Fluidized Bed •
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Advantages of Fluidized Bed The smooth liquid like flow of particle allow continuous automatically controlled operation with case of handling . Rapid mixing of solid leads to nearly near ly isothermal condition through the reactor, reactor, hence the operation can be controlled simply and reliably. reliably. It is suited to large scale operation . Circulation of solid between two fluidized beds makes it possible to transport the waste quantities of heat produced or needed in reactors Heat and mass transfer transfer rates between gas and particles are high when compared with other modes of contacting. The rates of heat transfer between a fluidized bed and immersed object is high
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Application & Examples
Solid-Catalysed Gas Phase Reaction •
Fluid Catalytic Cracking Reforming
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Phthal Phthalic ic and Maleic Maleic Anhidr Anhidride ide
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Oxid Oxidat atio ion n of so2 so2 and and so3 so3
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Polyeth Polyethylene ylene and Polypro Polypropyle pylene ne
Chlori Chlorinat nation ion and Bromi Brominat nation ion of Hydro Hydrocar carbon bon Gas-solid Reaction •
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Roasting of ores(Zns, Cu2S, sulphide ores)
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Combustion and incinerations incinerations
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Calcinations(limestone ,phosphates, aluminium, hydroxide)
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Reduction of iron oxide
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Fluorination of uranium oxide
Gasification, coking, and Pyrolysis / Carbonization Gas- Phase-Non Phase-Non catalytic catalytic reaction reaction •
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Natural gas combustion
Fluidized Bed •
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Advantages of Fluidized Bed The smooth liquid like flow of particle allow continuous automatically controlled operation with case of handling . Rapid mixing of solid leads to nearly near ly isothermal condition through the reactor, reactor, hence the operation can be controlled simply and reliably. reliably. It is suited to large scale operation . Circulation of solid between two fluidized beds makes it possible to transport the waste quantities of heat produced or needed in reactors Heat and mass transfer transfer rates between gas and particles are high when compared with other modes of contacting. The rates of heat transfer between a fluidized bed and immersed object is high hence heat exchange within fluidised within fluidized bed requires relatively small furnace area.
RAVI RAJ
EN-13118071
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Application & Examples
Solid-Catalysed Gas Phase Reaction •
Fluid Catalytic Cracking Reforming
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Phthal Phthalic ic and Maleic Maleic Anhidr Anhidride ide
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Oxid Oxidat atio ion n of so2 so2 and and so3 so3
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Polyeth Polyethylene ylene and Polypro Polypropyle pylene ne
Chlori Chlorinat nation ion and Bromi Brominat nation ion of Hydro Hydrocar carbon bon Gas-solid Reaction •
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Roasting of ores(Zns, Cu2S, sulphide ores)
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Combustion and incinerations incinerations
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Calcinations(limestone ,phosphates, aluminium, hydroxide)
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Reduction of iron oxide
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Fluorination of uranium oxide
Gasification, coking, and Pyrolysis / Carbonization Gas- Phase-Non Phase-Non catalytic catalytic reaction reaction •
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Gas liquid solid
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Hydro treating and hydro processing
Biochemical process Physical processes •
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Coating of surfaces
Flue gas (composition, tempera temperature, ture, uses) in Bl Blas astt Fur Furnac nace e
Flue gas is a by-prod by-product uct of blast blast furnace furnace that is is generate generated d when the the iron iron ore ore is redu reduced ced with with cok coke to met metall allic ic iron. iron. It has has a very very low low heat heating ing valu value. e.
Composition: CO2 :18-20%, CO :24-27%, H 2 :3-5% and N2 :55-57%(approximately)
Temperature: The temperature of flue gas as it leaves the furnace is 120-370 0C. This pressure is utilized to operate a generator (Top-gas-pressu (Top-gas-pressure re Recovery Recovery Turbine - i.e. TRT in short), which can generate electrical energy up to 35 kwh/t of pig iron without burning any fuel.
Uses: •
It is used as a fuel to preheat the air blast in blast furnace.
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Preheated BF gas along with preheated air has been used successfully in coke-oven
Flue gas (composition, tempera temperature, ture, uses) in Bl Blas astt Fur Furnac nace e
Flue gas is a by-prod by-product uct of blast blast furnace furnace that is is generate generated d when the the iron iron ore ore is redu reduced ced with with cok coke to met metall allic ic iron. iron. It has has a very very low low heat heating ing valu value. e.
Composition: CO2 :18-20%, CO :24-27%, H 2 :3-5% and N2 :55-57%(approximately)
Temperature: The temperature of flue gas as it leaves the furnace is 120-370 0C. This pressure is utilized to operate a generator (Top-gas-pressu (Top-gas-pressure re Recovery Recovery Turbine - i.e. TRT in short), which can generate electrical energy up to 35 kwh/t of pig iron without burning any fuel.
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It is used as a fuel to preheat the air blast in blast furnace.
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Preheated BF gas along with preheated air has been used successfully in coke-oven heating, soaking pits, and reheating furnaces.
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Flue gas is used for many applications in a steel plant and, in addition, is used frequently for heating coke ovens. Made by: Babita Babit a Bala (131 (1311801 18014), 4), Shraddha Suman (1312102 (13121025) 5)
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It is normally being used mixed with either coke oven gas or converter gas or both. The mixed gas is used as a fuel in various furnace of the plant . • Flue gas without mixing and without preheat can be used in 1.
Normalizing and annealing furnaces
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Blast Furnace stoves
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Foundry core ovens
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Gas engines for blowing
The thermal advantage of using flue gas in gas engines for blowing and for power generation has to overcome the heavy investment and maintenance expense required for such equipment. 5. Boilers for power generation The modern boiler house utilizes high steam pressure and temperature with efficient turbo-blowers and generators. This has sufficiently reduced the thermal advantage of gas engines and hence their use has become difficult to get justified.
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It is normally being used mixed with either coke oven gas or converter gas or both. The mixed gas is used as a fuel in various furnace of the plant . • Flue gas without mixing and without preheat can be used in 1.
Normalizing and annealing furnaces
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Blast Furnace stoves
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Foundry core ovens
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Gas engines for blowing
The thermal advantage of using flue gas in gas engines for blowing and for power generation has to overcome the heavy investment and maintenance expense required for such equipment. 5. Boilers for power generation The modern boiler house utilizes high steam pressure and temperature with efficient turbo-blowers and generators. This has sufficiently reduced the thermal advantage of gas engines and hence their use has become difficult to get justified. 6.Gas turbines for power generation. Made by: Babita Bala (13118014), Shraddha Suman (13121025)
BLAST FURNACE GAS CLEANING SYSTEMS • Because of the presence of substantial amount of CO in the BF flue gas, it has a considerable amount of calorific value and thus is utilized in hot blast stoves (for preheating hot blast), power plants and gas engines. However, for efficient use, gas has to be cleaned of the dust g (consisting of fine burden particles). • Initially, separation methods using water (wet methods) were implemented. At present, a combination of dry and wet methods is being used. The advantage – The dust separated via dry method can be again sent for sintering and fed in the Blast Furnace. DRY METHODS: Primarily use equipment called ‘Dust-Catchers.’ • Gravity Dust-Catcher: The flue gases are allowed to interact with some ascending gases so that the dust particles attain a terminal velocity and get separated.
BLAST FURNACE GAS CLEANING SYSTEMS • Because of the presence of substantial amount of CO in the BF flue gas, it has a considerable amount of calorific value and thus is utilized in hot blast stoves (for preheating hot blast), power plants and gas engines. However, for efficient use, gas has to be cleaned of the dust g (consisting of fine burden particles). • Initially, separation methods using water (wet methods) were implemented. At present, a combination of dry and wet methods is being used. The advantage – The dust separated via dry method can be again sent for sintering and fed in the Blast Furnace. DRY METHODS: Primarily use equipment called ‘Dust-Catchers.’ • Gravity Dust-Catcher: The flue gases are allowed to interact with some ascending gases so that the dust particles attain a terminal velocity and get separated. Schematic diagram of BF gas cleaning system
KN Sasidar(13118034) • Cyclone Dust-Catcher: The separation mechanism is based on the action of centrifugal forces on the dust particles. The gas is introduced through two tangential inlets (into a kind of shaft) with a velocity to force the dust particles to the wall and separate them from the gas stream.
WET METHODS After primary separation in the dustcatcher, or cyclone, the blast furnace top gas is scrubbed with water in the annular gap scrubber to obtain has a single tower construction comprises the pre-scrubber/cooler and the annular gap scrubber stages, and is followed by a high-efficiency, external moisture separator. The characteristics of the annular gap scrubber are: Multiple dust removal mechanisms, Minimum scrubbing water requirements and Superior top pressure control. The principal separating mechanisms in an annular gap scrubber are: Inertial interception, Turbulent (Brownian) diffusion and Flow line interception.
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Inertial interception : characterised by the different inertial forces of the varying masses. When the dust-laden gas flows around the collecting water droplet, the dust particles of larger mass do not follow the flow lines of the gas stream. These particles, propelled by the inertia force, strike and penetrate the water droplet, and thus are removed from the gas stream.
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Turbulent diffusion : highly effective in removing smaller dust particles from the gas stream. Small particles, particularly those below about 0.3μm in diameter,exhibit considerable Brownian movement and do not move uniformly along the gas streamline. These particles diffuse from the gas stream to the surface of the water droplets and are collected. This collection mechanism can only function in scrubbers that promote turbulent flow of a gas-liquid mixture, operate at low velocity and provide sufficient retention time.
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Flow-line interception : It only functions if the gas streamline passes within one particle radius of the collecting water droplet. The dust particle travelling along this streamline will touch the water droplet and will be collected. A cyclone followed by an annular gap scrubber offers High dust removal efficiency of 85% or higher and to a guaranteed value of 5mg/Nm3, minimum water requirement as the annular gap scrubber operates with a low and constant water-to-gas ratio, reduction the size of the water recycle system and thus minimising energy consumption, suit it up for installations for low top pressure furnaces as well as for installations with top gas energy recovery turbines.
• Cyclone Dust-Catcher: The separation mechanism is based on the action of centrifugal forces on the dust particles. The gas is introduced through two tangential inlets (into a kind of shaft) with a velocity to force the dust particles to the wall and separate them from the gas stream.
WET METHODS After primary separation in the dustcatcher, or cyclone, the blast furnace top gas is scrubbed with water in the annular gap scrubber to obtain has a single tower construction comprises the pre-scrubber/cooler and the annular gap scrubber stages, and is followed by a high-efficiency, external moisture separator. The characteristics of the annular gap scrubber are: Multiple dust removal mechanisms, Minimum scrubbing water requirements and Superior top pressure control. The principal separating mechanisms in an annular gap scrubber are: Inertial interception, Turbulent (Brownian) diffusion and Flow line interception.
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Inertial interception : characterised by the different inertial forces of the varying masses. When the dust-laden gas flows around the collecting water droplet, the dust particles of larger mass do not follow the flow lines of the gas stream. These particles, propelled by the inertia force, strike and penetrate the water droplet, and thus are removed from the gas stream.
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Turbulent diffusion : highly effective in removing smaller dust particles from the gas stream. Small particles, particularly those below about 0.3μm in diameter,exhibit considerable Brownian movement and do not move uniformly along the gas streamline. These particles diffuse from the gas stream to the surface of the water droplets and are collected. This collection mechanism can only function in scrubbers that promote turbulent flow of a gas-liquid mixture, operate at low velocity and provide sufficient retention time.
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Flow-line interception : It only functions if the gas streamline passes within one particle radius of the collecting water droplet. The dust particle travelling along this streamline will touch the water droplet and will be collected. A cyclone followed by an annular gap scrubber offers High dust removal efficiency of 85% or higher and to a guaranteed value of 5mg/Nm3, minimum water requirement as the annular gap scrubber operates with a low and constant water-to-gas ratio, reduction the size of the water recycle system and thus minimising energy consumption, suit it up for installations for low top pressure furnaces as well as for installations with top gas energy recovery turbines.
Made by Apurva
Gas Recycling
The concept of the Top Gas Recycling Blast Furnace relies on separation of the off gases so that the useful components can be recycled back into the furnace and used as a reducing agent. This would reduce the amount of coke needed in the furnace. In addition, the concept of injecting Oxygen (O2) into the furnace instead of preheated air, removes unwanted Nitrogen(N 2) from the gas, facilitating Carbon dioxide(CO 2) Capture and Storage (CCS). CCS plays an important role in Gas Recycling: A promising technology for significantly reducing the CO2 emissions from the blast furnace is to recycle reducing gases (CO and H2) leaving the furnace with the top gas. The re-use of these reducing gases lowers the usage of fossil carbon (coke). To reclaim them, however, the CO2 needs to be removed from the top gas, recycling the remaining gas back into the furnace. In addition, to avoid build-up of N2 in the furnace, the blast furnace needs to be operated with pure oxygen, instead of hot blast. For reaching a 50 % CO2 emissions reduction target, CCS technology is necessary to store the captured CO2. Prepared by: Vikram Kumar (13118105)
Gas Recycling
The concept of the Top Gas Recycling Blast Furnace relies on separation of the off gases so that the useful components can be recycled back into the furnace and used as a reducing agent. This would reduce the amount of coke needed in the furnace. In addition, the concept of injecting Oxygen (O2) into the furnace instead of preheated air, removes unwanted Nitrogen(N 2) from the gas, facilitating Carbon dioxide(CO 2) Capture and Storage (CCS). CCS plays an important role in Gas Recycling: A promising technology for significantly reducing the CO2 emissions from the blast furnace is to recycle reducing gases (CO and H2) leaving the furnace with the top gas. The re-use of these reducing gases lowers the usage of fossil carbon (coke). To reclaim them, however, the CO2 needs to be removed from the top gas, recycling the remaining gas back into the furnace. In addition, to avoid build-up of N2 in the furnace, the blast furnace needs to be operated with pure oxygen, instead of hot blast. For reaching a 50 % CO2 emissions reduction target, CCS technology is necessary to store the captured CO2. Prepared by: Vikram Kumar (13118105)
In blast furnace, gas generated occurs as by-product when iron ore is reduced to molten iron
(Fe). The operation of the blast furnace is controlled to produce hot metal of a specified quality and during this production BF gas comes out from the furnace top. Around 1500-1700 cu-m/ton of hot metal of BF gas is generated during the process.
CO2 and CO generation: When the hot air blast is blown in the furnace through
the tuyeres, Oxygen in the air reacts with coke to give carbon dioxide C(s) + O 2(g) CO2(g) ∆H= -58230 J then the limestone breaks down to form carbon dioxide CaCO3(s) CO2 (g) + CaO(s) ∆H= 41800 J Carbon dioxide produced reacts with more coke to produce carbon monoxide CO2(g) + C(s) 2CO(g) ∆H= 41500 J
CO/CO2 ratio can vary in a blast furnace from 1.25:1 to 2.5:1. Higher percentage of CO in the gas makes the BF gas hazardous. The
In blast furnace, gas generated occurs as by-product when iron ore is reduced to molten iron
(Fe). The operation of the blast furnace is controlled to produce hot metal of a specified quality and during this production BF gas comes out from the furnace top. Around 1500-1700 cu-m/ton of hot metal of BF gas is generated during the process.
CO2 and CO generation: When the hot air blast is blown in the furnace through
the tuyeres, Oxygen in the air reacts with coke to give carbon dioxide C(s) + O 2(g) CO2(g) ∆H= -58230 J then the limestone breaks down to form carbon dioxide CaCO3(s) CO2 (g) + CaO(s) ∆H= 41800 J Carbon dioxide produced reacts with more coke to produce carbon monoxide CO2(g) + C(s) 2CO(g) ∆H= 41500 J
CO/CO2 ratio can vary in a blast furnace from 1.25:1 to 2.5:1. Higher percentage of CO in the gas makes the BF gas hazardous. The
HCN and CN2 generation: In blast furnace some hydro cyanide (HCN) and Cyanogen gas (CN2) can also formed due to the
reaction of nitrogen in the hot air blast and carbon of the coke. The reaction is catalyzed by the alkali oxides. These gases are highly poisonous.
Rohit(13118074) and Jasjot(13118033)
H2 and CH4(water gas) generation:
Methane (CH4) can also be present in the BF gas up to 0.2% and H2 is around (3-5)%.
Any
moisture present in the hot air blast also reacts with the carbon of the coke. This reacti on consumes heat and produces more reducing gas which is a mixture of CO and H2. Hence where high blast temperatures are available (1000 deg C to 1200 deg C), the following reaction is favorable. C+H2O=CO+H2
∆H= 31400 J
The advantage of above reaction is that there is the introduction of hydrogen gas in the furnace reducing gases which decreases of the density of ascending gases.
N2 generation:
Nitrogen is not generated in the blast furnace by any chemical reactions but, Nitrogen from the air pass up through the furnace as fresh feed material travels down into the reaction zone.
H2S and COS generation:
Sulphur enters the blast furnace mainly in coke and is released into the blast furnace
H2 and CH4(water gas) generation:
Methane (CH4) can also be present in the BF gas up to 0.2% and H2 is around (3-5)%.
Any
moisture present in the hot air blast also reacts with the carbon of the coke. This reacti on consumes heat and produces more reducing gas which is a mixture of CO and H2. Hence where high blast temperatures are available (1000 deg C to 1200 deg C), the following reaction is favorable. C+H2O=CO+H2
∆H= 31400 J
The advantage of above reaction is that there is the introduction of hydrogen gas in the furnace reducing gases which decreases of the density of ascending gases.
N2 generation:
Nitrogen is not generated in the blast furnace by any chemical reactions but, Nitrogen from the air pass up through the furnace as fresh feed material travels down into the reaction zone.
H2S and COS generation:
Sulphur enters the blast furnace mainly in coke and is released into the blast furnace gas stream either as H2S or a gaseous compound of carbon monoxide and sulphur (COS) when the coke is burned.
FeO + COS = FeS + CO2 Jasjot(13118033) and Rohit(13118074)
IMPURITIES IN ORE •
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Main impurities in iron ore are silica, phosphorous, sulphur, alumina SILICA: Silica is the most common impurity. This is because of the physical contrast between silica-rich minerals, like quartz, and iron-rich minerals PHOSPHOROUS: Phosphorous is one of the nasty impurities in iron ore. It results in brittle iron. It is not easy to remove phosphorous so it is preferable that ores are low in phosphorous to start SULPHUR: Like phosphorous, sulphur is an impurity to avoid in iron ores. High sulphur ores (>0.01-0.03%) are to be avoided as it ultimately makes iron brittle, prone to cracking and failure. ALUMINA: Alumina is another common impurity in iron ores. This reflects its abundance in many other minerals which might also be included RAVI KANT with the iron ore minerals. 12118065 •
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GROUP 11
IMPURITIES IN ORE •
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Main impurities in iron ore are silica, phosphorous, sulphur, alumina SILICA: Silica is the most common impurity. This is because of the physical contrast between silica-rich minerals, like quartz, and iron-rich minerals PHOSPHOROUS: Phosphorous is one of the nasty impurities in iron ore. It results in brittle iron. It is not easy to remove phosphorous so it is preferable that ores are low in phosphorous to start SULPHUR: Like phosphorous, sulphur is an impurity to avoid in iron ores. High sulphur ores (>0.01-0.03%) are to be avoided as it ultimately makes iron brittle, prone to cracking and failure. ALUMINA: Alumina is another common impurity in iron ores. This reflects its abundance in many other minerals which might also be included RAVI KANT with the iron ore minerals. 12118065 •
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GROUP 11
is a fuel and reducing agent in Blast Furnace with few impurities and a high carbon content, usually made from coal.
Coke
It is the solid carbonaceous material derived from destructive distillation of low-ash, low-sulphur bituminous coal. Impurities present in coke are ash(inorganic residue after burning), Sulphur, Phosphorous and other volatile matter. Ash usually contains refractory oxides like SiO2,Al2O3,CaO,etc.. Phosphorous and Sulphur are also present in ash in the form of inorganic compounds.
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Coal available in India contains 2-7% of sulphur in it.
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All the Phosphorous and some part of sulphur goes into the pig iron.
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Sulphur in the coke requires additional flux for its removal or else sulphur content of iron goes up. Ash combines with the flux and is removed as slag. Shaik Syed Akram 13118081
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is a fuel and reducing agent in Blast Furnace with few impurities and a high carbon content, usually made from coal.
Coke
It is the solid carbonaceous material derived from destructive distillation of low-ash, low-sulphur bituminous coal. Impurities present in coke are ash(inorganic residue after burning), Sulphur, Phosphorous and other volatile matter. Ash usually contains refractory oxides like SiO2,Al2O3,CaO,etc.. Phosphorous and Sulphur are also present in ash in the form of inorganic compounds.
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Coal available in India contains 2-7% of sulphur in it.
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All the Phosphorous and some part of sulphur goes into the pig iron.
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Sulphur in the coke requires additional flux for its removal or else sulphur content of iron goes up. Ash combines with the flux and is removed as slag. Shaik Syed Akram 13118081
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The most frequent impurities in limestone are dolomite ,silica ,alumina , clay minerals , and the oxides and hydroxides of iron and manganese, as well as pyrite, phosphates, and organic matter . There are other trace elements that are present in limestone are sulphur , phosphorus, arsenic, manganese and fluorine.
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Phosphorous gets completely into molten iron.
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Molten Iron consists of 0.4-0.6 % Si , 0.1-0.2 % P , 0.040-0.050 % S , 0.1-0.5 % Mn.
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Alumina ,Silica , MgO , 0.1-1.2% Mn and 1-2% S goes into Slag. Other volatile materials are removed as gases. Anugu Shashank 13121003
The mix charged into a
The most annoying
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The most frequent impurities in limestone are dolomite ,silica ,alumina , clay minerals , and the oxides and hydroxides of iron and manganese, as well as pyrite, phosphates, and organic matter . There are other trace elements that are present in limestone are sulphur , phosphorus, arsenic, manganese and fluorine.
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Phosphorous gets completely into molten iron.
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Molten Iron consists of 0.4-0.6 % Si , 0.1-0.2 % P , 0.040-0.050 % S , 0.1-0.5 % Mn.
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Alumina ,Silica , MgO , 0.1-1.2% Mn and 1-2% S goes into Slag. Other volatile materials are removed as gases. Anugu Shashank 13121003
B A S I C S H O W T O R E M O V E I M P U R I T I E S
The mix charged into a blast furnace comprises Haematite (Iron ore mainly Fe2O3) Limestone CaCO3 Coke (source of C) •
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The limestone removes the silica as calcium silicate and phosphorus as phosphate which is called SLAG. This is molten and less dense than molten iron so floats on top. This has the advantage of preventing oxidation at the iron surface. The slag is tapped off periodically, and run off the surface of the iron. USES OF SLAG Slag is used in road making and as "slag cement" - a final ground slag which can be used in cement, often mixed with Portland cement.
The most annoying impurities for an iron maker are Silicon Phosphorus Carbon (in high levels) •
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The amount of carbon impurities in the iron is controlled by adding more or less coke at the top and also by controlling the length of the blast of air coming through at the bottom. The air will burn off the excess C Equations (Main ones) CaCO3 ===> CaO + CO2 SiO2 + Ca O ==> CaSiO3 C + O2 ===> CO2 C + CO2 ===> CO Fe2O3 + 3CO ===> Fe l + 3CO2
