Glencore and General Motors announced a multi-year sourcing agreement in which Glencore will supply GM with cobalt from its Murrin Murrin operation in Australia. Cobalt is an important metal in the production of EV batteries, and the cobalt processed from Australia will be used in GM’s Ultium battery cathodes, which will power electric vehicles such as the Chevrolet Silverado EV, GMC HUMMER EV and Cadillac LYRIQ.

Both Glencore and General Motors are members of the Responsible Minerals Initiative (RMI), and Glencore’s Murrin Murrin operation is conformant with the OECD-aligned Responsible Minerals Assurance Process.

Cobalt is a metal that makes up only 0.001% of the earth’s crust. It is known for its heat-resistant properties and is added to lithium-ion battery cathodes to improve energy density and battery longevity.

By the end of 2025, GM plans to have capacity to build 1 million electric vehicles in North America, and has announced a series of actions to create a new and more secure EV supply chain, including projects targeting key EV materials and components:

• Cathode Active Material (CAM) with POSCO Chemical. GM and POSCO Chemical are building a new facility in Quebec, Canada, as part of their joint venture to produce CAM for GM’s Ultium batteries.

• Lithium with Controlled Thermal Resources (CTR) to secure lithium produced by the first stage of its Hell’s Kitchen Project in California.

• Rare earth materials with GE, to develop a rare earth value chain.

• Alloy flakes with MP Materials, which will establish the first North American processing site for alloy flakes. The company will then expand into magnet manufacturing around 2025 at its new production facility in Fort Worth, Texas.

• Permanent magnets with VAC, the largest producer of permanent magnets in the Western Hemisphere with nearly 100 years of experience. VAC will establish a North American footprint to support GM’s magnet requirements starting in 2024, including locally sourced raw materials and finished magnet production.

Murrin Murrin is a remote, fully integrated nickel and cobalt producer located in the north-eastern Goldfields region of Western Australia. The company uses conventional open pit mining methods to extract the nickel and cobalt ore, before processing and refining the laterite ore at its hydrometallurgical facility.

The process plant consists of High Pressure Acid Leaching (HPAL) technology and a Refinery.

At the facility, the ore is sorted according to grade, crushed and blended to ensure consistent feed into the plant’s ore feed preparation circuit. The ore is then mixed with water to form a slurry for processing in the HPAL circuit. The HPAL circuit consists of four titanium-lined autoclaves, each the size of a small submarine.

The nickel and cobalt is leached out of the ore slurry, and into solution, by raising the pressure up to 44 atmospheres and mixing it with highly concentrated sulfuric acid at a temperature of 255 ˚C.

This generates substantial quantities of heat, which is recovered and then used to pre-heat incoming slurry.

Once the nickel and cobalt have been leached and are in soluble form, they must be separated from the residue waste material. This solution is washed to remove the waste residue, allowing the nickel and cobalt solution to move forward for further processing, and the residue to be neutralized for tailings disposal as inert waste.

Leached ore solution then passes into the neutralization circuit where calcrete is added to neutralize the acid.The solution is then passed into the mixed sulfides precipitation circuit, where hydrogen sulfide gas is added to convert the solution into a mixed nickel and cobalt sulfide precipitate.

The mixed nickel and cobalt sulfide enters another autoclave where pure oxygen converts the solids from a mixed sulfide into a metal sulfate solution. Impurities such as iron and zinc are then removed, before the cobalt and nickel are separated using solvent extraction.

The nickel sulfate solution then enters six parallel autoclaves, known as the hydrogen reduction circuit, where the hydrogen is added, nickel metal is precipitated and then separated from the nickel-free liquid stream. The nickel powder is then dried before entering the final processing stage.

The powder is formed into a pillow-shaped briquette, sintered in a furnace and then packaged for transportation.

The cobalt sulfate solution from solvent extraction follows a separate processing path which is similar to the nickel processing path but on a smaller scale, producing cobalt briquettes.

In 2021, Murrin Murrin produced 30.1 kt of nickel metal and 2.5 kt of cobalt metal, down 17% and 14% respectively, year-on-year, reflecting a lengthy scheduled statutory shutdown in May/June and various maintenance issues earlier in the year.