Process for recycling cobalt-bearing materials
The present invention concerns the recovery of cobalt from cobalt-bearing materials, in particular from cobalt-bearing lithium-ion secondary batteries, from the spent batteries, or from their scrap. A process is divulged for the recovery of cobalt from cobalt-bearing materials, comprising the steps of: providing a converter furnace, charging slag formers and one or more of copper matte, copper-nickel matte, and impure alloy into the furnace, and injecting an oxidizing gas so as to smelt the charge in oxidizing conditions, thereby obtaining a molten bath comprising a crude metal phase, and a cobalt-bearing slag, and separating the crude metal from the cobalt-bearing slag, characterized in that the cobalt-bearing materials are charged into the furnace. This process is particularly suitable for recycling cobalt-bearing lithium-ion secondary batteries. Cobalt is concentrated in a limited amount of converter slag, from which it can economically be retrieved, together with other elements such as copper and/or nickel.
1. Process for the recovery of cobalt from cobalt-bearing materials, comprising:
providing a converter furnace;
feeding cobalt-bearing materials, slag formers, and oner or more of copper matte, copper-nickel matte, and impure alloy containing copper and/or nickel into the converter furnace,
injecting an oxidizing gas into the converter furnace, thereby oxidizing any sulfidic materials present in the copper matte or copper-nickel matte to form sulfur dioxide, and obtaining a molten bath in the converter furnace comprising a crude metal phase and a cobalt-bearing slag, but free of sulfur; and,
separating the crude metal phase from the cobalt-bearing slag;
wherein the cobalt-bearing materials comprise secondary batteries, spent batteries, or their scrap and wherein more than 90% by weight of the cobalt present in the cobalt-bearing materials is recovered in the cobalt-bearing slag.
2. Process according to claim 1 , wherein the more than 90% by weight of the cobalt present in the cobalt-bearing materials is recovered in the cobalt-bearing slag, by adjusting the amount of oxidizing gas.
3. Process for the recovery of cobalt from cobalt-bearing materials according to claim 1 , wherein the cobalt in the cobalt-bearing slag amounts to between 2% and 20% by weight.
4. Process for the recovery of cobalt from cobalt-bearing materials according to claim 1 , further comprising a step of recovering cobalt and copper from the cobalt-bearing slag.
5. Process for the recovery of cobalt from cobalt-bearing materials according to claim 4 , wherein the step of recovering cobalt and copper from the cobalt-bearing slag comprises an acidic aqueous leaching operation.
6. Process for the recovery of cobalt from cobalt-bearing materials according to claim 4 , wherein the step of recovering cobalt and copper from the cobalt-bearing slag comprises a reducing smelting operation.
7. Process of claim 1 , comprising feeding cobalt-bearing materials, slag formers, impure alloy and one or more of copper matte and copper-nickel matte into the converter furnace.
8. Process of claim 1 , wherein the converter furnace is operated in tandem with a smelter.
9. Process of claim 1 , further comprising a smelting step, wherein the one or more of copper matte, copper-nickel matte, and impure alloy are produced in the smelting step.