The MONDO Minerals Nickel Sulfide Bioleach Project: From Test Work to Early Plant Operation

Mondo Minerals owns talc mines in Finland at Sotkamo and Vuonos. A by-product of their talc mining operations is a high-grade sulfide concentrate containing pyrrhotite, pentlandite, pyrite, gersdorffite and magnesite. Nickel is the main metal of economic interest, but the concentrate also contains a small amount of cobalt and a significant quantity of arsenic. Multiple processing options were evaluated before identifying Mintek’s bioleaching technology as the most suitable for the recovery of nickel and cobalt from this stream. This paper describes the technical development of the process, from laboratory test work to plant design and early plant operation.