The behavior of selenium and tellurium in metal-matte systems
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of s o l u t e s p e c i e s b e t w e e n two o r m o r e i m m i s c i b l e p h a s e s is a w e l l known phenomenon. It has b e e n w i d e l y u s e d in e x t r a c t i v e m e t a l l u r g y , both in low t e m p e r a t u r e a p p l i c a t i o n s such a s s o l v e n t e x t r a c t i o n and high t e m p e r a t u r e ones such a s the P a r k e s p r o c e s s for d e s i l v e r i n g l e a d . In t h e s e o p e r a t i o n s the s e l e c t i v e r e c o v e r y o r r e m o v a l of v a r i o u s c o n s t i t u e n t s is a c complished through their preferential concentration in one of the p h a s e s . T h i s s a m e b e h a v i o r should a l s o p e r m i t the s e l e c t i v e high t e m p e r a t u r e r e c o v e r y o r r e m o v a l of d i f f e r e n t e l e m e n t s , in p a r t i c u l a r t r a c e e l e m e n t s like s e l e n i u m and t e l l u r i u m , when d i s s o l v e d in i m m i s c i b l e m u l t i p h a s e m e l t s . H o w e v e r , such a p p l i c a t i o n s s e e m to have b e e n l i m i t e d . F o r e x a m p l e , in c o p p e r p r o d u c t i o n t h e r e a r e t h r e e s e q u e n t i a l m o l t e n t w o - p h a s e c o m b i n a t i o n s , m a t t e - s l a g , m e t a l - m a t t e , and m e t a l - s l a g . Yet only in the m e t a l - s l a g c o m b i n a t i o n in f i r e r e f i n i n g is any e f f o r t n o r m a l l y m a d e to u t i l i z e the p r e f e r e n t i a l d i s t r i b u t i o n of i m p u r i t i e s . In t h i s o p e r a t i o n p e r i o d s of o x i d a t i o n and d e o x i d a t i o n and s p e c i a l s l a g c o m p o s i t i o n s a r e u s e d to d r i v e d i f f e r e n t i m p u r i t i e s f r o m the c o p p e r into the s l a g p h a s e . 1-2 Now c h a n g e s in the c o p p e r i n d u s t r y a r e l e a d i n g to an i n c r e a s e d a w a r e n e s s of the i m p o r t a n c e of i m p u r i t y d i s t r i b u t i o n in m o l t e n s y s t e m s . New s m e l t i n g t e c h n i q u e s w i l l r e q u i r e a q u a n t i t a t i v e m e a s u r e of this type of i m p u r i t y b e h a v i o r b e c a u s e it p r o v i d e s the b a s i s for d e v e l o p i n g new r e f i n i n g s e q u e n c e s and for gaining a b e t t e r u n d e r s t a n d i n g of s m e l t i n g c h e m i s t r y . Q u a n t i t a t i v e d i s t r i b u t i o n d a t a f o r m e t a l - m a t t e s y s t e m s could a l s o l e a d to i n c r e a s e d f l e x i b i l i t y in c u r r e n t o p e r a t i o n s , e s p e c i a l l y t h o s e concluding with f i r e r e f i n i n g r a t h e r than e l e c t r o l y t i c r e f i n i n g . F o r e x a m p l e , e l e m e n t s which c o n c e n t r a t e to a high d e g r e e in the m e t a l o r the m a t t e p h a s e m i g h t be r e m o v e d d u r i n g the n o r m a l c o n v e r t e r c y c l e r a t h e r than in a s p e c i a l f i r e r e f i n i n g operation. Therefore quantitative metal matte distribution data a r e n e e d e d
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