Comparison of the bale-pelton and redlich-kister representations of thermodynamic properties of binary systems
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F i g . 4--Change of a v e r a g e CO2 composition with temperature.
r e d u c t a n t i s c o n s u m e d a n d r e g e n e r a t e d by s o l i d c a r Don F e O + C O = F e + CO2
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and CO2 + C = 2 C O .
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S h o w n i n F i g . 3 , CO2 i n g e n e r a t i n g g a s e x i s t s m o r e t h a n 10 p c t . T h e r e f o r e , d i r e c t r e d u c t i o n i s not s i g n i f i c a n t , but i n d i r e c t r e d u c t i o n i s d o m i n a n t . D a v i e s et al3 also i g n o r e d t h e d i r e c t r e d u c t i o n m e c h a n i s m , b e c a u s e t h e r e a c t i o n s u r f a c e was m u c h s m a l l e r t h a n that of i n d i r e c t r e a c t i o n . If t h e B o u d o u a r d R e a c t i o n [3] i s f a s t e r t h a n R e a c t i o n [2], CO2 g a s p r o d u c e d by R e a c t i o n [2] i s i m m e d i a t e l y c o n v e r t e d t o C O g a s . S o , the e v o l v e d g a s i s a l m o s t e x c l u s i v e l y c o m p o s e d of CO2. O n the c o n t r a r y , w h e n R e a c t i o n [2] i s m u c h f a s t e r t h a n R e a c t i o n [3], C O g a s r e g e n e r a t e d by R e a c t i o n [3] r e a c t s q u i c k l y t o CO2. T h e r e f o r e , t h e e v o l v e d g a s h a s t h e e q u i l i b r i u m g a s c o m p o s i t i o n of R e a c t i o n [2]. F i g . 4 , i n w h i c h r e s u l t s b a s e d on d a t a r e p o r t e d by K . O t s u k a e l a l v a n d B . K . S i m o n o v e t a la a r e a l s o p l o t t e d , s h o w s t h a t t h e c o n t e n t of CO2 i n g e n e r a t i n g g a s i s a l m o s t e q u a l t o the e q u i l i b r i u m g a s c o m p o s i t i o n o f l i q u i d i r o n o x i d e r e d u c t i o n by C O g a s . S o , i t i s c o n c l u d e d that t h e B o u d o u a r d R e a c t i o n [3] i s a r a t e - c o n t r o l l i n g s t e p . K r a i n e r et a l 2 a l s o m e a s u r e d the g a s c o m p o s i t i o n , u s i n g g r a p h i t e c r u c i b l e a n d t h e r e w a s n o CO2 i n g e n e r a t i n g g a s . T o e x a m i n e t h e i r r e s u l t s , u s i n g a g r a p h i t e c r u c i b l e i n s t e a d of t h e a l u m i n a c r u c i b l e , we m e a s u r e d t h e g a s c o m p o s i t i o n . T h e c o n t e n t of CO2 w a s no m o r e t h a n 0.5 p c t a t 1 6 7 3 , 1 7 7 3 , a n d 1873 K . O n t h e b a s i s o f t h e s e r e s u l t s , w h e n t h e g r a p h i t e c r u c i b l e w a s u s e d , CO2 a s a r e a c t i o n p r o d u c t w a s c o n s u m e d by the u p p e r p a r t o f t h e g r a p h i t e crucible w a l l . 3. S u m m a r y . T h e reduction o f m o l t e n i r o n oxide by s o l i d c a r b o n t a k e s p l a c e i n t h e f o r m of a c h a i n of r e a c t i o n s c o n s i s t i n g i n r e d u c t i o n by C O g a s a n d t h e B o u d o u a r d r e a c t i
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