SULFUR DETERMINATION USING GRAVIMETRIC METHOD OXIDATION OXIDATION ROASTING OF COPPER SULPHIDE ORE Romelyn B. Maandi METE !"#$ P%ROMETALLURGICAL ENGINEERING LABORATOR%
ABSTRACT Roasting converts the sulfide into the oxide form producing copper oxide. At the same time sulfiding occurs where copper sulfide is formed. Copper sulfide is insoluble to water and slightly soluble to HCl which makes it easy for the subsequent recovery processes. Eight samples of !g copper ore were weighed and put on crucibles. "hese samples were roasted at two given temperatures and four given time which were then cooled and weighed. "wo trials of each temperature were made for this experiment. And And the experimental data shows that it is evident that the weight loss increases as the time of roasting increases and that the weight loss also increases as the temperature increases. increases. Also reactions are relatively faster as the temperature increases. increases.
INTRODUCTION Copp Copper er##cont contai aini ning ng rock rock host hostss only only a small mall percentage of copper. $epending on to what minerals the copper is bound% the rock is processed in different ways in order to extract the valuable copper. "here are two main copper ore types of interest% copper oxide ores and copper sulfide ores.
sulfide with oxides. "he sulfur removed goes off as sulfur dioxide gas. "his can be done by giving the sulphide ore an oxidi(ing roast. "he ob+ect of the roast is to convert a considerable portion of the copper in the oxide form and a lesser amount is the form of sulfide% and all of the iron to ferric oxide which is insoluble in dilute acid.
MATERIALS AND METHODS "he most common source of copper ore is the sulfide ore which accounts for about &! percent of copper produce. 'ulfide copper ores are the most profitable ores because they have high copper cont conten ent% t% and and the the copp copper er can can be more ore easi easily ly separated from the unwanted minerals. However% sulf sulfid idee ores ores of copp copper er are are inso insolu lubl blee in dilu dilute te sulfuric acid leaching solutions% but a very high extraction can be obtained if the copper ore is in the the oxid oxidi( i(ed ed cond condit itio ion. n. )ith ith that that%% oxid oxidat ativ ivee roas roasti ting ng is appl applie ied d for for the the remo remova vall of sulf sulfur ur.. Another method in determining sulfur content is by gravimetric method. method.
OB&ECTIVES OF THE STUD% "his experiment aims to study the effects of time and temperature on the rate of removal of sulfur using oxidation roasting and the determination of 'ulfur 'ulfur using using gravim gravimetr etric ic method method from from a copper copper sulfide ore.
A. SULFUR DETERMINATION SULFUR DETERMINATION USING GRAVIMETRIC METHOD
"he materials that were used were Copper concentrate% &! m, graduated c ylinder% evaporating dish% -&! m, beaker% beaker% Analytical alance% alance% hot plate% stirring rod% filter paper% watch glass% *ven% and crucible. g of copper ore was weighed using /!!m, as container and a /!m, H0*1 H0*1 was added. 2t was then heated until &m, was left. A pinch of 'odium Carbonate 30aC*14 was added% evaporated and cooled. 2t was then dissolved in -!#1!m, HCl and boiled. After After boiling% &!m, of &5 arium Chloride Chloride solution was added and heated with cover. After After heated +ust below boiling% it was stirred and stand for - hours. After which% it was then filtered and transferred to a crucible. $ried in the oven for about 1! minutes 3!6C4. Cooled and then the weight was determined.
SIGNIFICANCE OF THE STUD% *xidative roasting is used to remove all or part of the sulfur from sulfide metal compounds replacing
7*xidation Roasting8.Submitted to Myra V. Cabatingan, Instructor. 9age ! of '
B. O(ida)ion Roa*)in o+ Co,,e- Sl,/ide O-e
"he materials that were used during the activity were Copper concentrate% Crucible% "ongs% "ube :urnace and Analytical alance.
"able above shows the respective weights obtained in the experiment. 'ulfur can be determined using the formula below >
( wt . BaSO ) ( S ) (100 )
%S =
4
( wt . sample ) ( BaSO ) 4
'o% :our samples of !g copper ore were weighed and put on crucibles labelled respectively as samples % -% 1 and /. At ;!!6C% sample was roasted for & minutes% sample - for 1! minutes% sample 1 for /& minutes and sample / for
%S =
( 2.52 g ) ( 32 g ) ( 100) ( 1.07 g ) ( 233.33 g ) %S =32.30
B. O(ida)ion Roa*)in o+ Co,,e- Sl+ide O-e TABLE 0A. )eight of the ore after roasting at ;!!6C
*re 'ample
Roasting
)eighing
"R2A, 2 3& minutes4 grams
31! minutes4 grams
1 3/& minutes4 grams
/ 3
-1.1@
-;.@
-1.1@
-;.@
!.!&
!.!@
!.!/
!.
11./1
1;.-<
11./-
1;.-=
Crucible 3after heating4
1-.@
1&.=1
1-.!/
1&.;<
)eight loss
.-&
.11
.1@
.&1
'A?9,E
)eighing
Cooling crucible
Figure 1. Process Flow for Oxidation oasting of a Co!!er Sulfide Ore.
R ESULTS AND DISCUSSION
ore Crucible ore
A. SULFUR DETERMINATION USING GRAVIMETRIC METHOD
TABLE !. )eight of a'*/ 9recipitate
)eight of 'ample 3g4
.!;
)eight of crucible 3g4
-;./
)eight of filter paper 3g4
.!
)eight after drying 3g4
1!.=1
)eight of a'*/ precipitate 3g4
-.&-
7*xidation Roasting8.Submitted to Myra V. Cabatingan, Instructor. 9age 0 of '
TABLE 0B. )eight of the ore after roasting at ;!!6C
TABLE 1B. )eight of the ore after roasting at &!!6C
"R2A, 22 'A?9,E
crucible
& 3& minutes4 grams
< 31! minutes4 grams
; 3/& minutes4 grams
@ 3
--.;
-1.1@
--.;
-1.1@
ore !.!1 Crucible ore
1-.;/
Crucible 3after heating4
1!.;<
)eight loss
.=@
!.!& 11./1 1-.!1
./
!.!/ 1-.;& 1!./;
-.-@
11./
31! minutes4 grams
1 3/& minutes4 grams
/ 3
crucible
-&.
--.=!
-&.-
--.@@
!.!/
!.!1
!.!;
!.!
1&.&
1-.=1
1&.=
1-.@=
Crucible 3after heating4
1/.!
1-.!1
1/.1&
1-.1
)eight loss
.!&
!.=
!.@/
!.;<
ore Crucible ore
.&
= 3& minutes4 grams
! 31! minutes4 grams
3/& minutes4 grams
3
-1.<1
--.<
-1.<1
--.=@
!.!1
!.!=
!.!/
!.!&
11.<<
1-.;!
11.<;
11.!1
Crucible 3after heating4
1-.<
1.=;
1-.@;
1-.-/
)eight loss
.!-
!.;1
!.@
!.;=
ore Crucible ore
3& minutes4 grams
1.=!
"R2A, 2
crucible
s 'A?9,E
!.!1
TABLE 1A. )eight of the ore after roasting at &!!6C
'A?9,E
"R2A, 22
"able A% "able % "able -A and "able - above shows the respective weights obtained in the experiment% for the samples roasted at ;!!⁰C and &!!⁰C for & minutes% 1! minutes% /& minutes and hour respectively. 2t is evident that the weight loss increases as the time of roasting increases 3"ableA4. "his is mainly because more time is allowed for the formation of sulfur dioxide. *n the other hand% weight loss also increases as the temperature increases. Reactions are relatively faster as the temperature increases. However% in roasting% temperatures too high should also be avoided in order to not melt the valuable metal. :or simplification of calculations% it is assumed that all the sulfur in the roasted feed is in the form of copper sulfide 3Cu-'4. Calculation of the total sulfur in the ore sample>
wt . Sulfur g Cu2 S × =
1 mol 159.1
g
Cu2 S ×
1 molSulfur 1 molCu2 S
"able below shows the weights of sulfur.
'ample
)eight of
5 'ulfur
'ample
2.02137
!.!&
7*xidation Roasting8.Submitted to Myra V. Cabatingan, Instructor. 9age 1 of '
×
32 g 1 mo
1 / &
!.!@ !.!/ !.
2.02740
2.01936
2.03343
2.03 2.03 2.03 2.02 % Sulfur 2.02 2.02 2.02 2.02 2.01 10 15 20 25 30 35 40 45 50
2.01735
!.!1 <
2.02137
; @
!.!& !.!/ !.!1
'ample
)eight of
= ! 1 / & <
'ample !.!1 !.!= !.!/ !.!& !.!& !.!@ !.!/ !.
2.01936
2.01735
Time of Roasting (min)
5 'ulfur
2.01735
2.02942
2.01936
2.02137
2.01936
2.01735
2.02539
2.01332
% Sulfur
ased on the observations made% it is concluded that the time and temperature of reaction is directly proportional to the degree of roasting. 2ncreasing time improves the quality of roast since the amount of copper sulfide decreases while the amount of copper sulfate and copper oxide increases.
0ow% oxidation of ore containing copper sulfide is according to the following equation> 3
Cu2 S + O2 →Cu 2 O + SO 2 2
Bncertainty of the composition of the samples makes it difficult to understand completely the effect of roasting on the samples. 2t is then recommended to have further examinations on the samples to determine its composition.
"herefore% the weight loss in the sample are considered to be the sulfur content in the copper sulfide ore oxidi(ing out as '*- gas. However% the weight loss obtained in the activity are significantly less than the calculated sulfur content of the ore when assumed as pure Cu-'. Also% if all the Cu-' ore was converted to Cu-*% the maximum weight it should have is 3'ample 4>
10.05 g Cu2 S ×
1 mol 159.1 g
Cu 2 S ×
1 mol 1 mol
)hich means that the maximum weight loss is only 1."1"#$ grams. "hus% it is assumed that the copper sulfide ore contains large amounts of impurities.
CONCLUSION AND R ECOMMENDATION
R EFERENCES 'tructural and compositional changes in copper sulfide during leaching and dissolution% )hiteside ,.'% oble R.D% "he Canadian ?ineralogist 3=@<4. -/ - -/;#-&@
Cu 0?R studies of copper sulfide 'hin#hachiro 'aito% Hideki Fishi% Foh+i 0iG% Hisaka(u 0akamaru% :umihiko )agatsuma% "akeshi 'hinohara% 9hys. Rev. &&% 3==;4% -% /&-; ) $avenport% ? Fing% ? 'chlesinger and A F iswas% %xtracti&e Metallurgy of Co!!er, Fourt' %dition 3Elsevier 'cience ,imited> Fidlington% *xford% England% -!!-
7*xidation Roasting8.Submitted to Myra V. Cabatingan, Instructor. 9age 2 of '
http>www.slideshare.netakshatcprincipals#of# roasting#and#its#types http>digitalcommons.mtech.educgiviewcontent.c giIarticleJ!-!KcontextJbachLtheses
7*xidation Roasting8.Submitted to Myra V. Cabatingan, Instructor. 9age " of '
