Nifty Copper Operation, located in the north-eastern part of Western Australia’s Pilbara region, is 100% owned by Australia’s biggest tin producer, Metals X.
Assisted by a huge sulphide copper endowment, it was operated as an underground mine until November 2019 when it was deemed unviable to continue the recovery of resources economically and therefore placed under care and maintenance. Metals X continues to maintain the infrastructure at the project site to be able to quickly resume operations.
The mine is now planned to be redeveloped as an open-pit copper mine. The results of a scoping study for a potential open-pit development were released in June 2020. The study investigated the potential of a significant expansion of Nifty’s historic oxide open-pit.
An A$10m ($6.93m) feasibility study will be conducted with a focus on further resource definition drilling. Estimated to take eight months to complete, the study will support the plans to restart an integrated open-pit and heap leach operation.
The company is expected to make final investment decision (FID) on the project in the first half of 2021 and employ more than 300 workers when the mine achieves full production.
Nifty copper mine location, geology, and mineralisation
The Nifty copper mine is located on the western edge of the Great Sandy Desert, approximately 350km south-east of Port Hedland.
The deposit is situated in the Broadhurst Formation within the Yeneena Supergroup of the Neoproterozoic Yeneena Basin. It is characterised by supergene oxide, sulphide, and transitional mineralisation occurring above strata-bound hypogene sulphide mineralisation.
The major sulphide minerals hosted in the deposit are chalcopyrite and pyrite, while minor minerals include sphalerite and galena.
Nifty copper mine reserves
The Nifty copper mine has total measured, indicated, and inferred resources of 47.29Mt grading 1.39% copper (Cu) and containing 658,500t of Cu, as of December 2019.
Mining and processing at Nifty copper mine
The scoping study for the open-pit operation considered the use of excavator and truck mining method. The mine will employ a traditional system with all mining operations to be carried out by Mining Plus, a mining contractor. The study identified three resource definition targets, namely northwest, west end, and southeast Supergene targets.
The mining will be performed using 120t hydraulic diesel excavator and 120t truck fleet, in at least four pit stages over ten years, based on the life of mine (LOM) mining plan that will yield a total concentrator feed of 23Mt grading 1.24% Cu and with waste to ore strip ratio of 7.6:1, on an average.
The current heap leach and solvent extraction/electrowinning (SX/EW) will be recommissioned to process the ore from the open-pit operation.
The processing plant infrastructure includes run-of-mine (ROM) pads with a capacity of more than 100,000t, a primary surface jaw crusher, and a flotation concentrator comprising semi-autogenous (SAG) mill, ball mill, filter plant, flotation cells, concentrator thicker, tails thickener, and paste fill plant. It is expected to have a long-term annual processing capacity of 2.8Mt.
Infrastructure facilities at Nifty mine
Mining at Nifty was being performed using the fly-in fly-out approach. The processing plant processes sulphide ore using comminution, grinding, and flotation for the production of clean copper concentrate.
The mining site is accessible by a sealed airstrip, which is serviced by flights from Perth. It can also be accessed via a bitumen road from Port Hedland to Woodie Woodie.
The site has a 400-room accommodation village with gymnasium, swimming pool, and tennis courts.
The copper mine operation is supported by a powerhouse comprising a 19.6MW GE dual-fuel gas/diesel turbine. Back-up resources include 5MW solar turbines, and 4MW Caterpillar and 2MW Detroit diesel generators. Gas is supplied via a 46km spur gas pipeline connected to the Port Hedland-Telfer pipeline.
The source of water is groundwater procured from a nearby borefield and mine dewatering.
Tailings storage facility at the project has the capacity to support the first two years of open-pit operations. Metals X is considering an expansion of the tailings storage facility for the open-pit project.
Mining Plus was contracted to conduct open-pit optimisation studies as part of the scoping study.
NewPro Consulting and Engineering Services was selected to assess the infrastructure condition and prepare cost estimate for the refurbishment. The contractual scope also includes metallurgical performance and operational cost guidance.
Nifty copper mine history
Oxide copper at the mine was first discovered in 1981. An open-pit, heap leach operation was started in 1993, while underground mine development was commenced in 2004 to exploit the sulphide resource.
The first copper concentrate was produced in 2006 and open-pit operations were suspended in the same year.
Metals X acquired the mine through the purchase of Aditya Birla Minerals in 2016.