PERTH (miningweekly.com) – Lithium miner Pilbara Minerals has produced its first concentrate from the coarse circuit at the recently restarted Ngungaju plant, in Western Australia.
Pilbara earlier this month took a final investment decision to restart the former Altura Mining’s lithium assets, after completing the $175-million acquisition in January this year.
The Ngungaju plant has nameplate capacity of some 206 000 t/y. By restarting the Ngungaju project, Pilbara’s output from the current 330 000 t/y of spodumene concentrate would climb to some 580 000 t/y, with plant improvements at the Pilgangoora operation to account for some 50 000 t/y of this additional output.
Pilbara on Wednesday told shareholders that the restart of the coarse circuit at the Ngungaju plant is expected to accelerate spodumene concentrate production, with construction, commissioning and ramp-up works progressing for both the fines and coarse concentrate circuits.
The restart of the coarse circuit will initially use existing weathered ore already stockpiled at Pilgangoora that was not amenable to flotation, but which now provides an opportunity for low-cost ore to be fed into the Ngungaju plant during the initial ramp-up period when concentrate is sourced solely from the coarse circuit.
This weathered ore feed is expected to be used through to the restart of production from the fines circuit, which is expected during the March quarter of next year, at which time fresh ore from the South Pit will be introduced to the Ngungaju plant.
Initial production from the coarse circuit is expected to yield lower lithia recoveries, which should improve once the fines circuit is re-commissioned and optimised. Full ramp-up of the Ngungaju plant at optimised lithia recoveries is expected by the middle of 2022.
The Ngungaju plant is targeting annual production capacity of approximately 180 000 t to 200 000 t by mid-2022, which will complement the existing production capacity from the adjacent Pilgan plant, which is currently producing at a rate of some 330 000 t/y, but increasing to 360 000 t/y to 380 000 t/y following completion of improvement works during the December quarter 2021.
Pilbara on Wednesday reported the start of concentrate production from the newly installed filter press at the Pilgan plant, as part of the plant improvement project currently being undertaken.
The A$22-million Pilgan plant improvements project is expected to de-bottleneck the facility to increase plant operating time and throughput, reduce final product moisture, and further manage product recovery performance. These improvements are ultimately expected to realise additional production capacity from the facility, and particularly from the fines flotation circuit.
Pilbara MD and CEO Ken Brinsden said the commencement of production from the Pilgan plant improvements project marked another significant and exciting milestone in the rapid growth of the Pilgangoora project.
“The team has done another amazing job in delivering this project on time and in line with budget. Keeping it on-track in combination with the restart of the Ngungaju plant is testament to the delivery capability of our team, particularly considering that these works were achieved during a period when the resources industry is under considerable pressure in terms of securing people, resources and equipment.”
Production from the Ngungaju plant is uncommitted to offtake and should support further sales into the emerging spot market for spodumene concentrate, including via the recently launched BMX digital sales platform.
For 2022, Pilbara is targeting spodumene concentrate production guidance across the entire Pilgangoora project of between 460 000 t and 510 000 t.