SEPARATION OF IRON FROM NICKEL AND COBALT. 159 
amount of acetateis used. Hither the sodium or ammonium 
Salts may be used. An increase of acetic acid tends to 
improve the separation, while an increase of acetate retards 
it; for example, taking 1° grm. of iron,*1 grm.of nickel, 10 cc. 
of 5 H. acetic and 10 cc. of 4°4 EH. ammonium acetate 
(122 ce. of *36 EH.) only ‘0884 grm. of nickel was recovered. 
His results show the acetate may be better added to a 
boiling solution than a cold one, though this is opposed to 
the usual custom. Contrary to the opinions of Moore and 
Mackintosh his results would show cobalt to be more readily 
separated from iron than nickelis. The acetate and acetic 
acid mentioned first above, was insufficient for 1° grm. of 
iron in the presence of ‘1 grm. of aluminium, but 60 cc. 
were necessary and only 98% of the nickel was then 
recovered. Nickel acetate though soluble in ammonium 
chloride is insoluble in acetic acid. Ferric acetate is 
decomposed at 100° C. into the hydrate and acetic acid. 
4, Phosphate Method. 
Cheney and Richards’ precipitated the ferric iron by 
sodium phosphate in the presence of acetic acid. With 
more than 3% of nickel reprecipitation was necessary, 99% 
of the nickel was recovered. Moore’ nine years later, 
apparently independently, published the same method 
recommending two precipitations for accurate work, but . 
gave no test analyses. 
Dd. Hlectrolysis. 
Le Roy’ deposits the nickel, cobalt, and iron from an 
ammonium citrate, sulphate, and hydrate solution, replaces 
it by a sulphate and hydrate one, and then reversing the 
current redissolves and reprecipitates the nickel and cobalt 
while the iron goes into suspension as ferric hydrate. No 
* Am. Journ. Sci., [3] x1v., 178-181, and C.N. 1877. 
2C.N., 1886, tiv., 306. 
oe be, Cu. 772-3. 
