Thermodynamics of dilute solutions of neptunium in liquid magnesium
- PDF / 273,583 Bytes
- 3 Pages / 612 x 792 pts (letter) Page_size
- 60 Downloads / 209 Views
LIQumm a g n e s i u m
a l l o y s have b e e n found to be u s e ful s o l v e n t s in p y r o c h e m i c a l p r o c e s s e s for the r e c o v e r y and p u r i f i c a t i o n of u r a n i u m and plutonium f r o m d i s c h a r g e d n u c l e a r f u e l s 1 and for the s e p a r a t i o n - o f t r a n s u r a n i u m e l e m e n t s . 2 The p r e s e n t study w a s und e r t a k e n to d e t e r m i n e the a c t i v i t y c o e f f i c i e n t of n e p tunium in liquid M g - N p a l l o y s in s u p p o r t of p r o c e s s d e v e l o p m e n t work. The a c t i v i t y c o e f f i c i e n t of neptunium in liquid m a g n e s i u m was d e t e r m i n e d f r o m e x p e r i m e n t a l d a t a on the d i s t r i b u t i o n of neptunium b e t w e e n a liquid MgC12NaC1-KC1 s a l t m i x t u r e and v a r i o u s liquid C d - M g a l l o y s . The d i s t r i b u t i o n d a t a w e r e u s e d to c o m p u t e the r a t i o of the a c t i v i t y c o e f f i c i e n t s of neptunium in liquid c a d m i u m and in liquid m a g n e s i u m . The a c t i v i t y c o e f f i c i e n t of neptunium in liquid m a g n e s i u m was then c o m puted f r o m the known v a l u e of the a c t i v i t y c o e f f i c i e n t in liquid c a d m i u m . E X P E R I M E N T A L PROCEDURE AND R E S U L T S Materials The a n h y d r o u s 50 m o l e pct MgC12-30 m o l e pct NaC120 m o l e pct KC1 s a l t m i x t u r e was obtained f r o m the A n d e r s o n P h y s i c s C o r p . The neptunium oxide c o n t a i n e d 0.5 pct PuO2. It w a s u s e d without f u r t h e r p u r i f i c a t i o n . The p u r i t y s p e c i f i c a t i o n s of the m a g n e s i u m and c a d m i u m w e r e 99.9 and 99.9999 pct, r e s p e c t i v e l y . Apparatus The liquid s a l t and a l l o y w e r e c o n t a i n e d in a t a n t a l u m c r u c i b l e with a t a p e r e d b o t t o m which was h e l d i n s i d e a t a n t a l u m s e c o n d a r y v e s s e l . The c r u c i b l e s were located inside a resistance-heated stainless steel f u r n a c e tube. The f u r n a c e tube top was e q u i p p e d with a tantalum thermowell, a tantalum stirrer, and a port t h r o u g h which s a m p l i n g t u b e s could be i n s e r t e d into the m e l t without a d m i t t i n g a i r into the f u r n a c e tube. C o n n e c t i o n s to v a c u u m and p u r i f i e d h e l i u m w e r e m a d e t h r o u g h a s i d e - a r m on the f u r n a c e tube. The m e l t t e m p e r a t u r e was m e a s u r e d by m e a n s of a c a l i b r a t e d c h r o m e l - a l u m e l t h e r m o c o u p l e l o c a t e d in the t a n t a l u m IRVING JOHNSON, JOHN J. HEIBERGER, and JACK FISCHER are Associate Chemist, Research Assistant, and Associate Chemist, respectively, Chemical Engineering Division, Argonne National Laboratory, Argonne, Ill. Manuscript submitted October 16, 1969. METALLURGICAL TRANSACTIONS
t h e r m o w e l l . The a c c u r a c y of the t e m p e r a t u r e m e a s u r e m e n t was +3~ The s a l t and a l l o y p h a s
Data Loading...
