SEPARATION OF NICKEL FROM COBALT AS ITS CHLOROSULPHATE ON SILICA-GEL LAYER WITH SOLVENTS CONTAINING FORMIC-ACID

Three-component solvent systems, viz formic acidpropanol-2-acetone, fo rmic acid-butanol-1-ethyl methyl ketone, formic acid-dimethylsulphoxid e-ethyl methyl ketone and formic acid-propanol-2-1,4-dioxane have been used to separate nickel from cobalt as its chlorosulphate on silica g el layer. The mobility of nickel chlorosulphate is found to be greater in solvent systems with higher formic acid concentration and it incre ases with the increase in formic acid concentration in the mobile phas e. The mobility of cobalt chlorosulphate also changes slightly with th e change in concentration of formic acid in the mobile phases. Both th e chlorosulphates are strongly adsorbed on silica gel layers in absenc e of formic acid.