398 F. S. Havens — Separation of Nickel and Cobalt, etc. 



and cooled to about 15° C. When saturation was complete the 

 precipitated chloride was caught on asbestos in a filter crucible, 

 washed thoroughly with a previously saturated solution of 

 ether, dissolved in water, evaporated with sulphuric acid and 

 determined as metallic nickel by the battery. The cobalt in 

 the filtrate was recovered by evaporation and electrolysis in 

 like manner. 



Experiments (1), (2) and (3) of the accompanying table show 

 that by this process the nickel is thrown down quantitatively, 

 and experiments (2) and (3) show that in the presence of a few 

 milligrams of the cobalt salt the separation of a small amount 

 of nickel is sharp. The residue of nickel in these experiments 

 gave no test for cobalt with the borax bead. When, however, 

 the cobalt is present to the amount of a few centigrams as in 

 (4), (5) and (6), the precipitated nickel chloride, which forms a 

 hard mass, includes the cobalt salt so that even a large quantity 

 of washing solution (100 cm3 was used in experiment 6) cannot 

 remove it. 





Nickel taken 



as the 



hydrous 



chloride. 



Nickel 

 found. 



Error. 



Cobalt taken 



as the 



hydrous 



chloride. 



Cobalt 

 found. 



p) 



0-0068 



0-0066 



— 0-0002 











2) 



0*0090 



0-0090 



0-0000 



0-0030 







(3) 



0-0090 



0-0091 



+ 0-0001 



0-0123 



0-0127 



(4) 



0-0469 



0-0490 



+ 0-0021 



0-0700 







(5) 



0-0468 



0-0503 



+ 0-0035 



0-0700 







(«) 



0*0472 



0-0493 



+ 0-0021 



0-0700 







Error. 



+ 0-0004 



From the experiments described it is obvious that the process 

 as proposed by Pineriia will not give a complete precipitation of 

 the nickel chloride. Nickel chloride is, however, practically 

 insoluble in pure ether saturated with hydrochloric acid gas and 

 can be separated from small quantities of the soluble cobalt 

 salt in that medium. In the presence of even a few centi- 

 grams of the cobalt chloride, however, the process is not prac- 

 ticable on account of the inclusion of the cobalt by the massive 

 nickel chloride. It is possible that by repeated solutions and 

 reprecipitations the nickel salt might be sufficiently freed from 

 the cobalt, but the process must naturally be long and tedious. 



In closing the author wishes to express his gratitude to Pro- 

 fessor G-ooch for kind suggestions. 



