Lixiviant

Example

See it in the plant

1. Charge: 13.18 t of black mass goes into the tank with 17.95 t of sulfuric acid and 1759 kg of hydrogen peroxide, 1.2× the stoichiometric floor.
2. Dissolve: stirred and heated, the metals go into solution (2 LiMO₂ + 3 H₂SO₄ + H₂O₂ → Li₂SO₄ + 2 MSO₄ + 4 H₂O + O₂). 98% of the nickel, 98% of the cobalt, 98% of the manganese, 99% of the lithium dissolves.
3. Filter: what does not dissolve stays on the cloth: 6037 kg of residue, mostly graphite and carbon. The liquid, 6331 kg of leach solution, goes on to purification.
4. Vent: 810 kg of gas leaves the tank, oxygen from the peroxide and vapour, to the scrubber.

Use in Lemonergy

Distinguish recovered material from a qualified product.

This is a reference concept. No executable Lemonergy block has been verified for this term.

Connected concepts

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Deep eutectic solvent

A mixture of two cheap compounds, such as choline chloride and urea, that melts far below either component and can dissolve metal oxides. It is studied as a milder, recyclable leaching medium for cathode materials.

Leaching

Dissolving the metals in black mass, usually in sulfuric acid with hydrogen peroxide as a reducing agent so cobalt and manganese go into solution as their more soluble lower oxidation state. The leach liquor carries lithium, nickel, cobalt and manganese, plus impurities such as copper and aluminium.

Pregnant leach solution

The solution that leaves the leach carrying the dissolved metals: lithium, nickel, cobalt and manganese, with copper, iron and aluminium as impurities. It is filtered from the leach residue and purified before the metals are separated.

Reducing agent

A substance that gives up electrons in a reaction. In leaching black mass, hydrogen peroxide is added as a reducing agent so cobalt and manganese go from their oxidised states in the cathode to the divalent state that dissolves readily. In smelting, carbon plays the same part.

References & further reading

Further reading on this topic

These sources provide broader context; they are not presented as citations for every statement in this entry.

1. Lithium-Ion Battery Recycling

   U.S. Environmental Protection Agency

   Topic background · Battery construction, recycling routes and U.S. waste-management context.

2. Recycling lithium-ion batteries from electric vehicles

   Gavin Harper et al. · Nature · 2019

   Topic background · Reuse, disassembly and mechanical, hydro-, pyro- and direct recycling routes.