What is “black mass”, and why is it such a significant opportunity for cobalt supply?

Black mass is the black, powder-like material produced when lithium-ion cells are stabilised and then shredded or crushed. It concentrates the most valuable battery metals, particularly those in the cathode, including cobalt alongside nickel, manganese and lithium. Because cobalt supply is highly exposed to geopolitical and ethical risks and prices have been extremely volatile, black mass is increasingly viewed as a strategic secondary feedstock for battery manufacturers. Recovering cobalt domestically from end-of-life batteries can reduce reliance on mined material and improve supply resilience. The opportunity is growing as EV and electronics battery volumes rise, with demand for cobalt exceeding 200kt in 2024 and forecast to keep increasing.

Which battery chemistries contain the most cobalt, and how does chemistry affect recycling economics?

Chemistry determines both cobalt content and the commercial value of recycling. Most cobalt sits in the cathode as lithium metal oxides. LCO batteries, common in higher-end phones and laptops, are typically the most cobalt-rich feedstock, with cobalt representing around 24% of battery weight, making them highly attractive from a cobalt perspective even though they are physically small. EV batteries are often NMC, where cobalt content varies by grade, such as around 20% in NMC 532 and NMC 622, and closer to 10% in NMC 811. Newer variants like NMC 955 reduce cobalt further. Because revenue depends on the contained metals, cobalt- and nickel-bearing chemistries usually recycle better financially than LFP, which contains neither.

How is cobalt actually recovered from black mass, and why is hydrometallurgy often preferred?

Cobalt recovery typically starts after packs are collected, sorted by chemistry to avoid cross-contamination, and disassembled into modules and cells. Cells are stabilised and comminuted into black mass, then processed using hydrometallurgy, which uses leaching and targeted separation steps to achieve high selectivity and purity. The process commonly begins with mineral acid leaching, followed by staged impurity removal to take out materials such as copper, iron and aluminium. Solvent extraction is then used to separate metals that behave similarly, enabling distinct streams for manganese, cobalt and nickel. Lithium is often recovered at the end as lithium carbonate. Compared with pyrometallurgy, hydrometallurgy generally avoids losing lithium and manganese to slag and reduces downstream refining to reach battery-grade outputs.

What are the biggest operational barriers to scaling cobalt recovery from end-of-life batteries?

The main constraint is not the extraction technology but reliable, safe and economical collection. Collection networks remain fragmented, and overall lithium-ion recycling rates are still under 10% despite large projected end-of-life volumes. Safety and logistics add substantial cost because damaged or “unknown state” batteries carry thermal runaway risk and must be treated as hazardous goods, requiring specialist ADR-compliant transport and UN-certified containers. Recycling sites also need separate procedures for damaged defective packs, which cannot be shredded like intact batteries due to residual charge and instability. Consumer electronics add another challenge: while often cobalt-rich, they are small and dispersed, so the cost of aggregating, transporting and processing many low-weight units can exceed the recovered value without robust infrastructure or support.

How do policy and incentives influence the business case for urban mining cobalt from batteries?

Policy is critical because it shapes collection volumes, compliance obligations and minimum demand for recycled content. The EU’s Extended Producer Responsibility framework pushes manufacturers and importers to fund and manage end-of-life batteries, while the revised Battery Regulation introduces rising recycled-content requirements, including cobalt, which strengthens long-term offtake and investment confidence. China is tightening control through vehicle-battery co-retirement rules and national traceability, again improving capture rates. The US supports domestic sourcing through clean vehicle credits tied to North American or partner-country extraction, processing and recycling, but lacks a single nationwide EPR-style system. Incentives may need to remain flexible because profitability varies by chemistry and commodity prices; for low-value chemistries like LFP, mechanisms such as gate fees or price floors for black mass may be needed to keep recycling viable.

Mining Technology

Critical Metals launches drilling at Greenland rare earth project

CRML has started a 10,000m drilling campaign at Greenland's Tanbreez project to support rare earth resource development.

Critical Metals (CRML) has commenced a 10,000m diamond drilling programme at its wholly owned Tanbreez Rare Earth Project in southern Greenland, as the company advances one of the world's largest undeveloped rare earth deposits.

The campaign is designed to support resource expansion, geological modelling, mine planning and future feasibility work at a project known for its significant concentrations of heavy rare earth elements, which are used in permanent magnets, electric vehicles, defence applications and advanced manufacturing.

The company recently completed accommodation and operational infrastructure at the site, with drilling contractors and support teams now mobilised and rigs deployed across priority target areas. Over the coming weeks, field teams will verify ground conditions, finalise drill collar locations and prepare access routes to support the programme.

In addition to drilling, work will include geological mapping, surface verification, collar surveys and environmental, health and safety monitoring. Data collected during the 2026 campaign is expected to inform future resource updates, feasibility studies and development planning.

CRML chairman Tony Sage said: “The start of our 10,000m drilling campaign marks another important step in the advancement of the world-class Tanbreez rare earth project. Following a successful mobilisation effort, drilling is now under way across priority target areas.

“The information generated from this programme is expected to support resource expansion, geological modelling, mine planning and other activities aimed at advancing Tanbreez toward production.”

In April this year, CRML signed a letter of intent to acquire all outstanding shares of European Lithium in a transaction valued at approximately $835m (A$1.19bn).