Leaching of high-solids, attritor-ground chalcopyrite concentrate by in situ generated ferric sulfate solution
- PDF / 441,247 Bytes
- 5 Pages / 603.28 x 783.28 pts Page_size
- 92 Downloads / 166 Views
J. KOLBE,
AND
H. W. HAYDEN,
JR.
Leaching of a t t r i t o r - g r o u n d c h a l c o p y r i t e c o n c e n t r a t e by acidified f e r r i c sulfate, g e n e r ated in situ, has b e e n studied. A i r and oxygen alone and mixed with s u l f u r dioxide were t e s t e d as oxidizing a g e n t s . A s p e c i a l l y d e s i g n e d r e a c t o r , which allowed in situ oxidation of f e r r o u s sulfate, p e r m i t t e d the leaching of a 20 pct solids s l u r r y with high copper r e c o v e r y . The leachate contained ~ 53 g/1 copper, a high enough c o n c e n t r a t i o n that s o l v e n t e x t r a c t i o n m a y not be n e c e s s a r y .
I N r e c e n t y e a r s , a c o n s i d e r a b l e a m o u n t of r e s e a r c h has b e e n devoted to developing h y d r o m e t a l l u r g i c a l p r o c e s s e s for leaching copper sulfide c o n c e n t r a t e s at a m b i e n t p r e s s u r e . 1-~ The i m p e t u s for such r e s e a r c h has b e e n the need for an e c o n o m i c a l p r o c e s s that does not g e n e r a t e SO2. F e r r i c c h l o r i d e , n i t r i c acid, a m m o nia, and f e r r i c sulfate a r e c o m m o n l y used l i x i v i a n t s for a m b i e n t leaching. F e r r i c chloride and n i t r i c acid leaching methods offer r e l a t i v e l y fast k i n e t i c s but, b e c a u s e of t h e i r c o r r o s i v e n a t u r e , r e q u i r e exotic m a t e r i a l s of c o n s t r u c t i o n . A m m o n i a c a l leaching p r o c e s s e s that a l s o offer f a v o r a b l e k i n e t i c s c o n s u m e a s i g n i f i c a n t a m o u n t of a m m o n i a , due to a m m o n i u m s u l fate b y - p r o d u c t f o r m a t i o n , and they also r e q u i r e s p e cial handling e q u i p m e n t due to the explosive n a t u r e of a m m o n i a and oxygen m i x t u r e s . A f e r r i c sulfate l e a c h ing p r o c e s s which has m i n i m a l c o r r o s i o n p r o b l e m s a p p e a r s to offer the b e s t p o s s i b i l i t y for providing fast k i n e t i c s at a m b i e n t p r e s s u r e . A c c o r d i n g l y , a joint r e s e a r c h effort* was u n d e r t a k e n *Thispaper describesa part of the work donejointlyat the MartinMarietta Laboratories,Baltimore,MD, and the Universityof Utah, Salt LakeCity, UT. to develop a new pollution free p r o c e s s to e x t r a c t copp e r and s u l f u r f r o m c h a l c o p y r i t e c o n c e n t r a t e using acid f e r r i c sulfate as a l i x i v i a n t . Kinetic study of the leaching p r o c e s s has shown that the leaching r a t e is independent of the f e r r i c ion c o n c e n t r a t i o n , provided that a m i n i m u m c o n c e n t r a t i o n of ~ 10 -2 M Fe .3 is m a i n t a i n e d in the leaching solution. 6 To obtain high leaching r a t e s at a m b i e n t p r e s s u r e , the p a r t i c l e size of c h a l c o p y r i t e is the only v a r i a b l e that n e e d s to be controlled, 7 and the n e c e s s a r y fine p a r t i c l e size can be achieved by g r i n d i n g in an a t t r
Data Loading...
