The open-pit Wodgina lithium project in the Pilbara region of Western Australia is the biggest hard rock deposit in the world. The project is estimated to have a mine life of 30 years.
Mineral Resources (MRL) acquired the mine from Global Advanced Metals in September 2016 and started mining operations in February 2017. The first shipment of 113,993 wet metric tonnes of lithium DSO from Wodgina was made in April 2017 from Port Hedland to China.
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MRL exported 3.4Mtpa of lithium direct shipping ore (DSO) in 2018 and expects to produce 5.5Mt of DSO in 2019.
MRL is currently expanding the Wodgina project to increase spodumene production and develop an integrated lithium hydroxide operation at the resource site. Construction of a new 750,000tpa spodumene concentrate plant commenced in March 2018, with commissioning scheduled for 2019.
Wodgina lithium mine expansion
MRL entered an agreement with Albemarle Corporation in November 2018 for creating a joint venture (JV) with equal share to own and operate the Wodgina lithium mine.
Albemarle has agreed to invest $1.15bn for 50% interest in the JV, which will combine the lithium production and marketing expertise of Albemarle with mining capabilities of MRL.
The expansion project will include the installation of a new spodumene concentrate plant and a lithium hydroxide plant, while upgrading the crushing plant. The project is expected to produce 750,000tpa of 6% spodumene concentrate from three beneficiation modules or trains, which will be used to feed to the lithium hydroxide plant.
The new lithium hydroxide plant will be developed in two stages. The first stage is expected to produce 50,000tpa of battery-grade lithium hydroxide, while the remaining spodumene concentrate will be processed and converted into battery-grade lithium hydroxide in the second stage.
The second stage is expected to increase the plant’s capacity to 100,000tpa.
A new 10Mt capacity three-stage crushing plant is also being constructed and is planned to be completed by the end of 2018.
Wodgina lithium project geology and mineralization
Located approximately 109km from Port Hedland, Wodgina mine is classified as a North Pilbara basement terrane and comprises a series of ovoid multi-phase granitoidgneiss domes neighbored by sinuous synformal to monoclinal greenstone belts.
The Cassiterite pit of Wodgina lies on the 25km-long Wodgina Greenstone Belt, which consists of inter-layered mafic and ultramafic schists and amphibolites.
Mineralization is contained within multiple sub-parallel, sub-horizontal pegmatite intrusive bodies trending in north-east direction. The pegmatites have a strike length from 200m to 400m.
Lithium in the Cassiterite pit is contained in grey-white spodumene crystals within medium-grained pegmatites hosting quartz, feldspar, spodumene, and muscovite.
Wodgina lithium project reserves
As of October 2018, the Cassiterite pit of Wodgina lithium mine was estimated to hold 151.9Mt of probable ore reserves grading 1.17% lithium.
Mining and ore processing at Wodgina
Conventional open-pit mining methods are being used at the Wodgina mine to recover DSO. The mining fleet includes Hitachi EX3600 excavator, two CAT 994 front-end loaders (FEL), and Caterpillar CAT789D haul trucks.
Ore will be crushed in three stages – primary, secondary, and high-pressure grinding roller crushing. Crushed ore will undergo ball milling and de-sliming followed by iron extraction.
The product will then pass through a conventional spodumene flotation circuit followed by spodumene concentrate filtration. The final spodumene will be delivered to the Port Hedland for Albemarle.
Proposed infrastructure facilities at Wodgina
The existing infrastructure at Wodgina includes a 14MW gas power station, 81km-long four-inch natural gas lateral pipeline, accommodation camp, a single crushing plant, tailings storage facility, and water supply.
The natural gas lateral pipeline will be upgraded to ten-inch diameter, and 32 gas gensets with a capacity of 2MW each will be installed.
Water will be supplied from the bore fields located in the project area, while rooms in the accommodation camp will be increased to 750.
An all-weather airstrip, capable of landing A320 jet aircraft, is being constructed approximately 10km from the project area.
Financing
In July 2018, MRL secured A$450m ($334m) bridge loan from syndicate partners for the Wodgina project construction.
Contractors involved
MRL has awarded drilling and blasting services contract for the Wodgina project to Ausdrill.
Hatch conducted the pre-feasibility study of the hydroxide plant at Wodgina, in addition to feasibility study of the proposed downstream plant to produce lithium hydroxide or lithium carbonate.
MRL has engaged Macquarie Capital (Australia) and Gilbert + Tobin for assisting the company for the sale of minority interest in Wodgina.
Widenbar and Associates drafted a new mineral resource estimate for the lithium project on the basis of updated re-sampling, infill drilling, and blast hole sampling data.
Water Technology, a consulting company based in Australia, prepared an integrated storm water management assessment design for the Wodgina mine, while OSD was engaged for the front-end engineering design (FEED) of the new gas pipeline, and design and commissioning of the pipeline system.
