Clean process of recovering metals from waste lithium ion batteries

A process of recovering metals from waste batteries including lithium ion batteries, wherein said waste batteries which include metals of iron, aluminum, copper, cobalt, and lithium are calcined and sieved to generate an ash containing metals and metal oxides, said process comprising the following steps:

• a) dissolving said ash with a 3N-6N hydrochloric acid aqueous solution containing sodium chloride;
• b) using the dissolved solution formed in step a) as a cathode solution and an aqueous solution of salt or acid as an anode solution, and using a current density of 0.001-0.01 ampere/cm2 to perform a membrane electrolysis in a first electrolysis tank divided into a cathode well and an anode well by a cationic exchange membrane, thereby forming by reduction a copper metal on a cathode in said cathode well, wherein hydrogen ions formed in said anode solution penetrate through said cationic exchange membrane, and combine with the chlorine ions in said cathode solution to form hydrochloric acid;
• c) withdrawing said cathode solution from said first electrolysis tank, and applying a diffusion dialysis on said cathode solution, thereby obtaining an aqueous solution of hydrochloric acid and a solution with an elevated pH value, wherein said aqueous solution of hydrochloric acid can be recycled for the use in dissolution in step a);
• d) using said solution with an elevated pH value from step c) as a cathode solution and an aqueous solution of salt or acid as an anode solution, and using a current density of 0.01-0.05 ampere/cm2 in a second electrolysis tank divided into a cathode well and an anode well by a cationic exchange membrane to perform a membrane electrolysis, wherein the pH value of said cathode solution is controlled to be over 1.5 during said membrane electrolysis process, thereby forming by reduction a cobalt metal on a cathode in said cathode well;
• e) withdrawing said cathode solution from said second electrolysis tank, and adjusting the pH value thereof to 5-7, thereby forming a precipitation of Fe(OH)3 and Al(OH)3;
• f) performing a solid/liquid separation on the resulting mixture from step e);
• and
• g) adding a water soluble carbonate into the aqueous solution separated in step f), thereby forming a precipitation of lithium carbonate.