Battery recycling
Process for the recovery of Co or Ni, comprising the steps of: preparing a metallurgical charge comprising Fe, slag formers, and a useful load containing either one or both of Co and Ni; feeding the charge to a shaft furnace; and smelting the charge so as to form a Co or Ni-bearing alloy, an Fe-bearing slag and a gaseous phase, characterised in that the useful load comprises at least 30 wt. % electrochemical batteries or their scrap, and in that the redox potential in the furnace is chosen so as to slag at least 20 wt. % of the Fe, and at most 20 wt. % of the Co or 20 wt. % of the Ni present in the charge.
1. Process for the recovery of Co and Ni, comprising the steps of:
preparing a metallurgical charge comprising Fe, slag formers, and a useful load containing either one or both of Co and Ni;
feeding the charge to a shaft furnace; and
smelting the charge so as to form a Co or Ni-bearing alloy, an Fe-bearing slag and a gaseous phase,
wherein the useful load comprises at least 30 wt. % electrochemical batteries or their scrap, and wherein the redox potential in the furnace is chosen so as to slag at least 20 wt. % of the Fe, and at most 20 wt. % of the Co or 20 wt. % of the Ni present in the charge.
2. Process according to claim 1 , wherein the slag formers are chosen so as to produce a final slag composition with an SiO 2 to CaO ratio of at least 1.
3. Process according to claim 1 , wherein at least one plasma torch provides energy to an upper part of the shaft furnace.
4. Process according to claim 1 , wherein the gaseous phase undergoes a post-combustion step using at least one plasma torch as energy source.
5. Process according to claim 1 , further comprising the steps of separating and refining Co, Ni, or Co and Ni from the alloy.
6. Process according to claim 1 , wherein at least 90 wt. % of the Co or Ni present in the charge is recovered.
7. Process according to claim 1 , wherein a Zn-bearing material is added to the charge.
8. Process according to claim 7 , wherein the Zn-bearing material comprises alkaline primary batteries.
9. Process according to claim 1 , wherein the slag formers are chosen so as to produce a final slag composition with an SiO 2 to CaO ratio of at least 1.5.
10. Process according to claim 1 , wherein the shaft furnace comprises:
a smelting and reducing zone providing rising countercurrent gas;
a preheating zone preheated by the rising countercurrent gas; and
a plastic pyrolising zone positioned between the preheating zone and the smelting and reducing zone.
11. Process according to claim 10 , wherein the charge is preheated in the preheating zone to a temperature under 300° C. by the rising countercurrent gas from the smelting and reducing zone before smelting the charge.