STUDY ON THE RECOVERY OF NICKEL SULPHATE FROM CHROMIUM-NICKEL WASTE SOLUTION BY OXALATE PRECIPITATION

Abstract

Direct effluent from chromium-nickel-plate basin contains high content of
nickel, from 6.7g/l to 15.6g/l. Nickel is precipitated in the form of NiC2O4 at
pH = 6-7, residual H2C2O4 is 100%. Under this condition nickel is recovered with
high efficiency, about 94-96%. The purity of NiC2O4 precipitate is about 96-98%.
NiC2O4 precipitates are completely converted into nickel sulphate with acid H2SO4
and H2O2. The nickel sulphate solution is quantified and reused in the chromiumnickel process.