Seperation & Recovery of Copper & Nickel from Copper Bleed Stream by Solvent Extraction Route

Abstract

Bleed stream from electro r(fining step of copper slnelter was processed to recover the metals as high value products such as copper and nickel powders or salts. The process consists of partial decopperisation of the bleed stream followed by crystallisation of a ,nixed salt of copper and nickel sulphate, leaching of the mixed salt, removal of iron, solvent extraction separation of copper and nickel and winning the solution to produce metal powders. With the partially decopperised bleed stream, the composite crystal was obtained by crystallisation which contained 8.4 -12.5 % Cu and 13.7-14.38 % Ni with 1-2pptn Fe as impurity. This mixed salt was leached with water and was treated for iron precipitation. The purified solution was subjected to solvent extraction using LIX 84 and CYANI X 272, A 20% LIX 84 in kerosene extracted 99.88% copper acrd 0,059% nickel (if ct p1I of 2.5 and 5% C}'ANEX 272 in kerosene extracted 98,06% copper and 0.511, nickel at a p!I of 4.85. 1,L1' 84 was usec! for metal separation in the ,fixer-seiller unit. The pure solutions of copper and nickel sulphates obtained from stripping circuit were electrolysed to produce pure copper (99.9%) and nickel (99.8) powders; alternatively pure sulphate salts could also be crystallised.