A process and method for producing a crystallized metal sulfate. The crystallized metal sulfate may be battery-grade. The method may comprise receiving a metal ion-containing stream and crystalizing a metal sulfate from the stream. The process may comprise receiving a stream from a metal processing plant, and crystalizing a metal sulfate from the stream. The process may be a metal electrowinning process comprising crystalizing a metal ion-containing stream to form a crystallized metal sulfate in a mother liquor. The process or method may comprise returning the mother liquor upstream or to the metal electrowinning process.

A method for preparing high-purity mixed nickel and cobalt sulphate, the method comprising the recovery of nickel and cobalt sulphate crystals from an organic phase rich in both nickel and cobalt by way of contacting the nickel and cobalt rich organic phase with an aqueous strip solution of sufficient H2SO4 concentration to extract nickel and cobalt from the organic phase and of sufficient Ni.sup.2+ and Co.sup.2+ concentration to precipitate nickel and cobalt sulphate crystals and form a nickel and cobalt lean organic phase. Also disclosed is a method for the optimisation of feed for downstream processing.

A method for preparing high-purity mixed nickel and cobalt sulphate, the method comprising the recovery of nickel and cobalt sulphate crystals from an organic phase rich in both nickel and cobalt by way of contacting the nickel and cobalt rich organic phase with an aqueous strip solution of sufficient H2SO4 concentration to extract nickel and cobalt from the organic phase and of sufficient Ni.sup.2+ and Co.sup.2+ concentration to precipitate nickel and cobalt sulphate crystals and form a nickel and cobalt lean organic phase. Also disclosed is a method for the optimisation of feed for downstream processing.