Extraction of yttrium in the system Y(NO 3 ) 3 -HNO 3 -H 2 O-Di(2-ethylhexyl) phosphoric acid
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The e x p e r i m e n t a l p r o c e d u r e s were as d e s c r i b e d p r e v i o u s l y . 1 D 2 E H P A was diluted w i t h A m s c o , a h y d r o c a r b o n d i l u e n t w i t h a b o i l i n g r a n g e b e t w e e n 177 ° t o 199°C. T h e y t t r i u m o x i d e , w i t h a p u r i t y of g r e a t e r t h a n 99.9 p c t w i t h r e s p e c t t o o t h e r r a r e e a r t h s , w a s o b tained from the R a r e - E a r t h Separation G r o u p of Ames Laboratory. T h e e q u i l i b r a t i o n of the a q u e o u s a n d o r g a n i c p h a s e s w a s d o n e i n a s e p a r a t o r y f u n n e l by s h a k i n g t w o t i m e s f o r 15 r a i n w i t h a 30 m i n i n t e r v a l , u s i n g a s h a k i n g m a c h i n e . T h e equilibrated s o l u t i o n s were a l l o w e d to s e t tle overnight. T h e y t t r i u m in t h e e q u i l b r a t e d a q u e o u s p h a s e a n d in the s t r i p s o l u t i o n w a s d e t e r m i n e d by E D T A t i t r a t i o n , u s i n g a r s e n a z o a s the i n d i c a t o r . 23 T h e f r e e a c i d i n t h e a q u e o u s p h a s e w a s titrated with s o d i u m hydroxide solution, u s i n g m e t h y l orange as t h e indicator. R E S U L T S A N D DISCUSSION T h e e x p e r i m e n t a l r e s u l t s a r e s h o w n i n T a b l e I, a n d p l o t t e d on F i g s . 1 a n d 2 . I n T a b l e I, the i n i t i a l c o n c e n t r a t i o n of D 2 E H P A w a s e x p r e s s e d on a m o n o m e r b a s i s . T h e s o l u b i l i t y o f Y(NO3)s • 6H20 in n i t r i c a c i d w a s f o u n d t o be 0 . 4 9 5 , 1 . 5 6 , 2 . 6 4 , a n d 3.63 M f o r 1 4 . 8 , 8 . 2 0 , 4 . 1 8 , a n d 0 M HNO3 c o n c e n t r a t i o n s , r e s p e c t i v e l y . T h e HNOs a n d y t t r i u m n i t r a t e c r y s t a l s w e r e s h a k e n f o r 30 m i n in a n E r l e n m e y e r f l a s k a t 2 5 ° ± 0.1 °C. T h e s o l u b i l i t y of Y ( N O s ) s - 6 H 2 0 w a s d e t e r m i n e d by t i t r a t i n g a n a l l TAKEO HARADA, formerly Post-Doctoral Associate, Chemical EngineeringDivision,Ames Laboratory, U. S. Atomic Energy Commission, Iowa State University, Ames, Iowa, is Assistant Professor, Department o f Oceanography, Faculty of Fisheries, Hokkaido University, Hakodate, Japan. RENATO G. BAUTISTA is AssociateChemical Engineer, Chemical Engineering Division,A m es Laboratory and Assistant Professor, Department of Chemical Engineering, Iowa State University. MORTON SMUTZ, formerly Deputy Director, Ames Laboratory, and Professor of Chemical Engineering, Iowa State University, is now Associate Dean of Engineering, University of Florida, Gainesville, Fla. Manuscript submitted May 2 1 , 1970. METALLURGICAL
TRANSACTIONS
T a b l e I. E q u i l i b r i u m D a t a f o r t h e System Y ( N O 3 ) 3 - H N O 3 - H 2 0 D 2 E H P A i n A m s c o , at 2 5 ° C
Initial D2EHPA Concentration ci moles/liter
Final Acidity inA q u e o u s Phase H moles/liter
0.310 0.310 0.310 0310 0.310 0.310 0.310 0.310 0.310 0.310 0.310 0.310 0310 0.310 0.310 0.310 0.310 0.310 0.
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