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METE E – 112 (Metallurgical Analysis) Laboratory Report ACTIVITY 1: PROXIAMATE ANALYSIS of COAL
Performed by: Al Ignatius F. Mabolis
Submitted to: Prof. Nadzmi S. Sayadi INTRODUCTION All over the world, there has always been the prevalence of coals. A coal is a solid, usually brown or black, carbon-rich material that most often occurs in stratified sedimentary deposits as the most important of the primary fossil fuels. In modern utilization, coal has been used as a source of energy; as a chemical feedstock from which
numerous synthetic compounds can be derived and other productions for metallurgical processes. Coal has chemical components and properties and there are commonly employed systems of classification that can be performed in the laboratory using two analyses. Hence, coal can be analysed in the form of “proximate” and “ultimate” analyses. The experiment conducted used the typical proximate analysis of the moisture, ash, volatile matter, and fixed carbon contents of coal samples after heated and weighed. Proximate analysis has been used to determine the rank of coals by separating volatile components, fixed carbon and inert components.
It is important because
proximate analysis helps in giving a vague idea about the quality of coal used in different industries based on their requirements.
OBJECTIVE The experiment determined the content of a coal sample on its:
moisture ash volatile matter fixed carbon
MATERIAL/APPARATUS Electric muffle furnace (up to 100°C), with temperature and draft control Mettler balance Porcelain capsule with cover Desiccator with silica gel Spatula Drying oven (104-110°C) with air holes
Coal sample passing No. 60 mesh sieve non-sparking
PROCEDURES The following procedures were observed throughout the experiment: A. Moisture Determination According to ASTM D3173-73 Heat the capsule with the cover in the drying oven at 104-110°C, cool over a desiccant and weigh, put approximately one gram of coal sample using a
spatula, close and weigh at once. Remove the cover, place the capsule in the preheated oven and heat for one hour. Open the oven, cover the capsule, cool the capsule over
desiccant and weigh as soon as it is cold. B. Ash Determination According to ASTM D3174-73 (79) Place the porcelain capsule with the dried coal sample from the moisture determination in a cold muffle furnace and gradually heat to redness. Finish the ignition to constant weight ( ±0.1 mg) at a temperature between 700 and 750°C. Cool in a desiccator and weigh as soon as cold. C. Volatile Matter Determination According to ASTM D3175-77 Weigh one gram of sample in a weighed porcelain crucible, close with cover and put directly into the furnace at 950°C. After the more rapid discharge of VM hs subsided, inspect the crucible to verify if lid is still properly seated. If necessary, reset the lid to quickly prevent admission of air and put the crucible back to the 950°C zone. After heating for exactly 7 minutes remove the crucible from the furnace and without disturbing the furnace, allow it to cool and then weigh
RESULTS AND DISCUSSIONS
A. Results Trial 1 2
Sample Moisture Content grams grams % 2.002 0.648 32.37 2.005 0.752 37.51
Ash Content
grams 0.672 0.712
% 33.57 35.51
Volatile Matter grams % 0.195 9.73
Fixed Carbon grams % 0.487 24.33 0.346 17.25
The objective of proximate analysis indicates the percentage by weight of the moisture and ash contents as well as volatiles in coal. Ash content of a coal is the residue after the combustion of coal at specified condition s. This residue does not occur originally in the coal but as a result of chemical changes that occur during the combustion process. The amounts of fixed carbon and volatile combustible matter directly contribute to the heating value of coal. Fixed carbon acts as a main heat generator during burning. High volatile matter content indicates easy ignition of fuel. The ash content is important in the design of the furnace grate, combustion volume, pollution control equipment and ash handling systems of a furnace.
Table 4.1 Tabular Data for Moisture Determination Initial Weight of
Weight of capsule
Remaining
Moisture
capsule
after heating, W2
coal sample,
content, %
(w/o cover) + 2 g of
(g)
(g)
coal, W1 (g) 27.170
26.522
0.648
32.37
29.454
28.702
0.752
37.51
Moisture content , =
W 1−W 2 27.170−26.522 ×100 = × 100 =32.37 initial g of coal 2.002
Moisture content , =
W 1−W 2 29.454−28.702 ×100 = ×100 =37.51 initial g of coal 2.005
Table 4.2 Tabular Data for Ash Determination Weight of empty
Weight of capsule,
Initial weight
capsule and cover,
cover, and ash
of coal
Wa, (g) 25.168 27.449
residue, Wb, (g) 25.850 27.990
sample, (g) 2.002 2.005
Ash content , =
W b −W a 25.850−25.168 ×100 = ×100 =34.07 initial g of coal 2.002
Ash content , =
W b −W a 27.990−27.449 ×100 = ×100 =26.98 initial g of coal 2.005
Ash content, %
34.07 26.98
Table 4.3 Tabular Data for Volatile Matter Initial
Initial
Weight of
Weight of
Volatile
Weight of
Weight of
crucible
the crucible
Matter, %
crucible
crucible +
after
at 950°C,W2
2 g of coal,
heating, W1
(g)
(g) 30.191
(g) 29.413
29.218
28.087
Volatile Matter , =( W 2−W 1) ×100 =( 29.413−29.218 ) ×100 =19.5 Table 4.3 Tabular Data for Fixed Carbon
19.5
Volatile Matter,
Moisture
Ash Content, %
Fixed Carbon, %
%
Content, %
19.5
32.37
34.07
14.06
37.51
26.98
16.01
¿ Carbon, =100−( %VM + %M+ %ASH )=100−(19.5+32.37+ 34.07)=14.06 ¿ Carbon, =100−( %VM + %M+ %ASH )=100−(19.5+37.51+26.98)=16.01
CONCLUSION AND RECOMMENDATION The data in this study demonstrates that the desiccator is capable of giving reproducible proximate analysis of coal. It can be concluded that coal sample passing No. 60 mesh sieve non-sparking has close proximate analysis data compared to other coal. This work using proximate analysis as performed with ASTM analyzer continues to be a useful tool for rapid analysis of small quantities of coal. It is recommended that a sturdier container for the coal sample should be used to avoid a crucible from breaking when heating at a very high temperature.
REFERENCES Kopp, O. C. (2016). Coal. Fossil Fuel. Retrieved on February 22, 2017 from URL: https://www.britannica.com/science/coal-fossil-fuel Cassel, B. and Menard, K. (2016). Proximate Analysis of Coal and Coke using the STA 8000 Simultaneous Thermal Analyzer. Retrieved on February 23, 2017 from
URL: http://www.perkinelmer.com/CMSResources/Images/44142549APP_Proximate_Analysis_Coal_Coke.pdf
