The plant is on track for commissioning in June 2023, the company said. Detailed design of the plant is 75% complete, with costs estimated between £6.5 to £7.0 million (US$7.5 to US$8.1 million).

Engineers have designed the foundation slab for the plant, while the shuttering and steel reinforcement is now complete. The treated water discharge duct from the plant to the middle engine shaft is also complete.

Cornish Metals has begun the pouring of concrete.

Six large steel clarifier tanks will be built locally, with delivery and installation to begin in December.

"It is wonderful to see the level of activity underway at South Crofty, as we progress through the construction of the Water Treatment Plant, and undertake a metallurgical sample drill programme," chief executive Richard Williams said.

Cornish Metals is also working on dewatering the mine. The company purchased two submersible pumps in 2018, which have now been checked and tested. Cornish Metals will install the pumps into the New Cooks Kitchen shaft in November. Both pumps will be installed at approximately 370 metres below surface by the end of February 2023.

Workers have removed parts of the NCK shaft headframe to prepare for installation, and pump and pipe handling infrastructure has been installed and tested. All steel pipes for pumping are now at the mine site and are ready for installation.

Cornish Metals has ordered a new single drum winder, which will be delivered in the September quarter of 2023. The new drum winder will allow for better access to the NCK shaft.

Cornish Metals has begun initial work on the feasibility study.

The company now has over 30 full-time employees on site, as well as contractors.