Method for separating cobalt, nickel, and copper metals contained in waste lithium-ion batteries via selective leaching

Sequential Cobalt and Nickel Separation Process Using Primary Methanesulfonic Acid Leaching and Secondary Sulfuric Acid Leaching

This technology is a hydrometallurgical leaching process that selectively dissolves and separates cobalt and nickel in stages by precisely controlling solution type, acid concentration, reaction temperature, and pulp density for metal mixtures obtained from heat-treated waste lithium-ion batteries.

Existing waste battery metal recovery processes require complex multi-stage treatments involving both pyrometallurgical and hydrometallurgical methods, leading to high recovery costs and significant environmental impact. Furthermore, low selective separation efficiency between metals has made it difficult to recover high-purity metals.

This technology is designed to preferentially leach cobalt at 45°C or lower in a first solution containing methanesulfonic acid and hydrogen peroxide, and then selectively dissolve nickel by immersing the remaining residue in a second solution based on sulfuric acid (with hydrogen peroxide if necessary). It can be applied to recycling waste batteries from small IT devices with high cobalt content and to converting copper residues into separate smelting raw materials, reducing the burden of subsequent purification by separating metal-specific solutions through a simple two-stage leaching process.

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Key Features:

• A step of selectively dissolving cobalt by immersing metals obtained from heat-treated waste lithium-ion batteries in a first solution containing methanesulfonic acid and hydrogen peroxide
• A step of selectively dissolving nickel by immersing the residue, from which cobalt has been selectively dissolved, in a second solution containing sulfuric acid
• A first solution for cobalt leaching composed of a methanesulfonic acid concentration of 1.5–2.5 mol/L and a hydrogen peroxide concentration of 10–30% (v/v)
• A cobalt leaching step of maintaining a metal pulp density of 120–200 g/L and controlling the reaction temperature at 45°C or lower

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This invention was developed with support from the Ministry of Trade, Industry and Energy for the development of 2,000-ton/year-scale high-temperature reduction smelting commercialization and concentration/separation technology for recovering valuable metals from medium-to-large waste lithium secondary batteries.

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