JOHANNESBURG (miningweekly.com) – Amsterdam-headquartered talc producer Mondo Minerals and South Africa’s State-owned Council for Mineral Technology (Mintek) are currently constructing a Mintek-developed nickel sulphide bioleach plant at Mondo’s Vuonos talc processing site, in Finland.

This followed the conclusion of a licence agreement between the parties that provided Mondo exclusivity in applying Mintek’s bioleaching process for the recovery of nickel and cobalt from a sulphide concentrate by-product in return for financial and intellectual contribution to the technology’s development.

The plant, which would be commissioned in August, was expected to treat about 12 000 t/y of nickel concentrate, producing about 1 000 t/y of nickel at full production.

The currently-under-construction plant was designed to withstand the cold winter conditions in Finland.

Mintek would provide on-site support, including the provision of the process start-up material, the training of Mondo’s operational staff and technical assistance during plant commissioning, at Mondo’s facility, explained Mintek biotechnology division specialist engineer John Neale, who was responsible for the transfer of the technology to Mondo.

Mintek biotechnology division’s head of biometallurgy Mariekie Gericke explained that the licence agreement was the outcome of a two-year metallurgical testwork programme, where the application of Mintek’s technology to treat the by-product from Mondo’s talc production process had been developed and successfully demonstrated.

A feasibility study showed that bioleaching, combined with a nickel- and cobalt-precipitation process, was an economically-viable option for Mondo to derive value from this by-product.

“An important aspect of the process is that it includes the production of a stable arsenic-bearing waste to be impounded,” Gericke said.

The agreement extended Mintek’s product offering to include nickel and cobalt. The council had previously applied its bioleach technology to the treatment of refractory gold concentrates for projects in Australia and China.