A rapid electrochemical method for measuring the concentration of active glue in copper refinery electrolyte which conta
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A F T E R c o p p e r i s s m e l t e d , it i s u s u a l l y e l e c t r o r e f i n e d to p u r i f y i t s u f f i c i e n t l y f o r e l e c t r i c a l a p p l i c a t i o n s and to r e c o v e r p r e c i o u s m e t a l s w h i c h follow it t h r o u g h the s m e l t e r . V a r i o u s o r g a n i c r e a g e n t s a r e a d d e d to the a c i d s u l f a t e r e f i n i n g b a t h to p r e v e n t nodul a t i o n of t h e c a t h o d e s , to c o n t r o l ~ahe p h y s i c a l and c h e m i c a l p r o p e r t i e s of the c a t h o d e s , and to h e l p cont r o l the i n s o l u b l e s l i m e s w h i c h f o r m . T h e s e r e a g e n t s u s u a l l y i n c l u d e glue and often i n c l u d e t h i o u r e a , both at carefully controlled concentrations. D u r i n g e l e c t r o r e f i n i n g the glue i s c o n s u m e d by i n c o r p o r a t i o n into t h e d e p o s i t , by a c i d - c a t a l y z e d h y , d r o l y s i s , and by a d s o r p t i o n onto the s l i m e s . T h e r e f o r e , it m u s t b e r e p l e n i s h e d on a continuous b a s i s . A s v a r i o u s f a c t o r s a f f e c t t h e c o n s u m p t i o n of r e a g e n t s , c o n s t a n t a d d i t i o n r a t e s do not a s s u r e a c o n s t a n t o r o p t i m u m i n s t a n t a n e o u s c o n c e n t r a t i o n of glue. A s e l e c t r o l y t e is t r a n s f e r r e d b e t w e e n a c t i v e u s e a n d s t o r a g e , t h e r e a r e a l s o c h a n g e s in r e a g e n t l e v e l s and n e e d s . T h e r e f o r e , it i s d e s i r a b l e to b e a b l e to m e a s ure reagent concentrations. M e t h o d s f o r s u c h m e a s u r e m e n t a p p e a r to b e s p a r s e . D i r e c t c h e m i c a l m e t h o d s a r e v e r y t i m e c o n s u m i n g and d i f f i c u l t b e c a u s e the r e a g e n t s a r e p r e s e n t a t only the ppm level whereas the solution is concentrated with m a n y i n o r g a n i c s u b s t a n c e s . A l s o , t h e h y d r o l y s i s p r o d u c t s of glue, s u c h a s a m i n o a c i d s , c o n t a i n m o s t of t h e s a m e f u n c t i o n a l g r o u p s a s t h e glue, i t s e l f . R e a g e n t b a l a n c e in r e f i n e r i e s i s u s u a l l y a c c o m p l i s h e d by v i s u a l i n s p e c t i o n of cathode q u a l i t y , with p r e v i o u s e x p e r i e n c e a s t h e guiding f a c t o r in r e a g e n t a d d i t i o n s . T h i s m e t h o d h a s t h e d i s a d v a n t a g e of c u r i n g problems after they occur. Also, the cathode deposit q u a l i t y i s a function of s e v e r a l v a r i a b l e s in a d d i t i o n to t h e r e a g e n t l e v e l , so t h a t p r o p e r r e s p o n s e to d e p o s i t p r o b l e m s can be v e r y d i f f i c u l t . T. N. ANDERSEN is Senior Scientist, Kennecott Research Center, Salt Lake City, UT. R. D. BUDD and R. W. STRACHAN are Project Metallurgist and Senior Project Engineer, respectively, Kennecott Refining Corporation, Baltimore, MD. Manuscript submitted November 26, 197
