Cobalt Blue Holdings is now eyeing large-scale test samples to be shipped next month after confirming that its demonstration plant in Broken Hill, New South Wales, is now transitioning to operations.

The company has completed the design, build and commissioning of Broken Hill or BHCP, and has wrapped up mining of 2,300 tonnes of ore. It is now moving to operations for the remainder of the plant so it may produce mixed hydroxide precipitate (MHP) and cobalt sulphate.

During 2021, Cobalt Blue successfully built and operated a smaller scale pilot plant, which has now been upgraded to increase capacity with all processing unit operations to treat ore to produce both products.

This demonstration plant contains a kiln for thermal decomposition of pyrite into pyrrhotite and elemental sulphur; an autoclave circuit for leaching pyrrhotite; an iron removal circuit; a MHP circuit; a refining circuit to produce cobalt sulphate; and on-site production of oxygen for leach and nitrogen for the kiln.

The plant’s goal is to treat 3,000 to 4,000 t and produce 10 t of cobalt products. Ore for the plant is being sourced from the Pyrite Hill deposit, and a 60-metre-long underground portal was developed to access the orebody.

Cobalt Blue chairman Rob Biancardi said: “Twenty-four-hour operations will commence shortly across the entire demonstration plant. This reflects real progress by our technical team and will allow BHCP to ship large scale test samples during Q3, providing a strong backdrop to commercial discussions.”

The demo plant program is expected to operate in aggregate for 20 weeks on a 24/7 basis. It will be split into campaigns to allow for analysis and optimisation of the plant performance. Samples of MHP and cobalt sulphate will be provided to prospective offtake parties. Early supply of samples will assist with qualification into the battery manufacturing chain, ahead of future commercial operations at the BHCP.