SEP.AR.ATIOK O F 1IET.IL I O S S RY CYTIOS EXCHLSGE
47 1
dEP*IR.ITIOS OF METAIL IOSS BY C-ITIOS T
H E JYI1,TOX
-1o ~ t h i ~ ~ s i cI i- )i iii i c r s i i 1 .
Rccciictl
.Iiti.c
Eioii\loti
Zllitioi?
14, 1946
It is it aell-knonn fact that metal ions are taken up preferentiallv from solution by materials capable of cation exchange. I t should, theretore. he possible to separate a mixture 01 cations of ~ a r y i n gionic size I J paszaqe ~ through an exchanger. This principle has been used hy Russell and I'earce i l ) 111 a n attempt to fractionate the rare earth+. Tests ha\ e here heen made TI ith a number of different mixtures--copper a n ~ lnickci, radmium and zinc. siiwr and copperto deteiniine n hether a practical ciuanti:xtiT e -eparation could be attained hy cation eschange. E X P L R I ~ I E \r 11,
'The cation exchange1 iiseti was the iiilfonatc 1 coal hnon n as Zeo-Karb, liicli ai firit \ra.:hed with concentrated hyclrochloric acid to remove metallic cation> and small amounts of iron oxide and then rinsed n i t h n-ater. All experiments but the last one cited ircre perlormed in n 2-ft. column of 20-mm. glass tubing, containiiig TO g. of Zeo-Kaih In the last experiment, a W t . column. containing 244 g. Zeo-Iiaiil. u a s used. I n most cases. the solution contaming R mixtiire of t n o salt.: was pa-ed through the exchanger at a rate or about 10 nil. per minute until one of the inetal ions began to appeal in the eifluent. The metals i t eie then regenerated TI itli acid, 100-mi. fiactions being collected and a!ialyzcd 130th ammoniacal :md sl~ghtiyacid solutions of varying concrntrntions v e i c tried Save typical rehiilt> m e given in table 1 11
c O ~ c 1 . ~ - ~ 1 0 ~
'Ihe fractionation of mctal ion. 17)- cation eschange does not give a quantitative separation. The methoti coulti be improved liy using a n:uch longer column, Iiut the proce- u ould thex not 1.e as practical as chemical separation. This investigation western I-nivemity.
IIXS
siipportccl by a gmni from the Abbott Fund of S o r t h 1IEFE:ItES ('E
(1) RL-SSELL.+xnPE.IWE:tJ. ~ i 1 1 1 .('hem. SOC.65, 595-600 11913).
472
R.
BOZAK - 4 S D H. F. WALTON
TABLE 1 Separation of metal ions b y cation exchange INELUENT
RECIESER.AN1
,
EFFLUENT FRACTION
ANALYSIS
ml.
Cu and Si analyzed electrolytically millimoles Cu 13.4 33.4 12.7
0-100 100-200 200-500
200-400
peared in effluent
I
I
100-200 200-300 300-800
+
2 liters AgSS04 (0.01 M) CuSOc (0.01 -14); stopped when Cu first appeared in effluent
0- 100 500-600 600-700 in0-1300
12.4 26.0
7.0
__
-
59.5
45.4
0.5
-
-
6.8 5.4 16.6
12.9 0.8 0.2
0.5
__
-
29.8
18.7
millimoles A g
2 M HZSOc
millimoles Si
0.6 3 .-I
millimoles Cu
5.1
14.6 1.3 0.5
21.7
0.1
30.8
16.5
