The BioNIC process: description of the process and presentation of pilot plant results

摘要

The BioNIC Process is being developed by GENCOR as a competitive process to conventional smelting for the recovery of nickel from low-grade sulphide ores. The development work is being carried out at GENCOR Process Research, Randburg South Africa, together with MINTEK. MINTEK are collaborating in developing the technology for the downstream treatment of the liquors arising from bioleaching to recover copper, nickel and cobalt. The BioNIC process flow sheet involves the following principal unit operations: i) bioleaching to oxidise metal sulphides and release soluble metals into solution; ii) adjustment of pH to remove iron; iii) solid/liquid separation; iv) production of a sulphide precipitate, or concentration and purification of the process liquor by ion-exchange or solvent extraction to produce an upgraded electrolyte; v) electrowinning of the upgraded electrolyte to produce a pure nickel cathode, or hydrogen reduction to produce nickel powder.