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t r a n s f e r p h e n o m e n a involving liquid m e t a l s take place in p y r o m e t a l l u r g i c a l r e f i n i n g of m e t a l s as well a s in e x t r a c t i v e m e t a l l u r g i c a l p r o c e s s e s . The e c o n o m i c s of o p e r a t i n g t h e s e p r o c e s s e s has n e c e s s i tated i n v e s t i g a t i o n and e v a l u a t i o n of n u m e r o u s p r o b l e m s of m a s s t r a n s f e r a p p a r e n t in liquid m e t a l s y s t e m s . D i s s o l u t i o n k i n e t i c s and m a s s t r a n s f e r in i r o n b a s e d m e l t s have b e e n studied d u r i n g the past decade for v a r i o u s solid m a t e r i a l s used in s t e e l m a k i n g p r o cesses. Studies on d i s s o l u t i o n of solid i r o n or c a r b o n s t e e l into liquid i r o n - c a r b o n alloys o r pig i r o n b a t h s b e c a m e of i n t e r e s t as the s c r a p - m e l t i n g p r a c t i c e gained m o r e i m p o r t a n c e in the b a s i c oxygen s t e e l m a k i n g p r o c e s s . A n u m b e r of i n v e s t i g a t i o n s *-~ have b e e n u n d e r taken to e v a l u a t e the k i n e t i c s of s o l u t i o n of solid i r o n in m o l t e n i r o n baths. T h e s e i n v e s t i g a t i o n s a r e in a g r e e m e n t that the r a t e of d i s s o l u t i o n is c o n t r o l l e d b y m a s s t r a n s f e r in the liquid phase. However, t h e s e s e v e r a l s t u d i e s employed d i f f e r e n t e x p e r i m e n t a l t e c h n i q u e s , including induction s t i r r e d s y s t e m s , and d i f f e r i n g i n t e r pretations were drawn concerning various experimental p a r a m e t e r s , in p a r t i c u l a r the effects of c a r b o n content in liquid and solid, and the q u a n t i t a t i v e influence of fluid d y n a m i c c o n d i t i o n s in the liquid. The following i n v e s t i gation was u n d e r t a k e n to develop a q u a n t i t a t i v e m a s s t r a n s f e r c o r r e l a t i o n a p p l i c a b l e to the s o l u t i o n r a t e of solid s t e e l into liquid i r o n .

solid f r o m the bulk liquid l o w e r i n g the m e l t i n g point of the solid at the i n t e r f a c e and the s u r f a c e r e a c t i o n of phase t r a n s f o r m a t i o n t a k e s place with a b s o r p t i o n of the e n e r g i e s of r e a c t i o n . When the d i s s o l u t i o n of p u r e i r o n or a solid i r o n c a r b o n alloy in a liquid i r o n - c a r b o n a l l o y t a k e s p l a c e u n d e r " i s o t h e r m a l " conditions, m a s s t r a n s f e r b y v o l u m e diffusion in the liquid through a b o u n d a r y l a y e r has b e e n e s t a b l i s h e d as the r a t e - c o n t r o l l i n g step. *-7 Under n o n - i s o t h e r m a l conditions, heat t r a n s f e r m a y be l i m i t i n g . 8 The s u r f a c e r e a c t i o n of phase change at the s o l i d - l i q u i d i n t e r f a c e is r a p i d enough to m a i n t a i n the e q u i l i b r i u m c o m p o s i t i o n s c o r r e s p o n d i n g to the t e m p e r