Method for recycling waste cemented carbide by molten salt chemistry

A method for recycling waste cemented carbide by molten salt chemistry, comprising:

• (1) mixing a molten salt media consisting of a compound A, a compound B and NaCl with waste cemented carbide and dehydrating the mixture under a vacuum condition;
• a dehydration temperature is 70˜300° C.;
• a mole percentage content of the compound A, the compound B and the NaCl in the molten salt media is 5˜30 mol %, 0˜60 mol % and 10˜50 mol % respectively;
• the compound A is selected from a group consisting of Na2O, CaO, K2O, CoO/CoO3, WO3, Na2WO4, K2WO4 and CaWO4, and the compound B is selected from a group consisting of CaCl2), KCl and LiCl;
• (2) stirring the molten salt media containing the waste cemented carbide and introducing an oxidizing gas to carry out oxidation-dissolution reaction;
• wherein a reaction temperature is 300˜1000° C.;
• (3) deoxidizing a molten salt reaction system after the oxidation-dissolution reaction by introducing chlorine containing gases and a deoxidation temperature is 300˜1000° C.;
• (4) carrying out thermal reduction reaction on the deoxidized molten salt reaction system to obtain a mixture by adding reductant;
• wherein a reaction temperature for the thermal reduction is 400˜850° C.;
• (5) washing, filtering and drying the mixture obtained in the step 4 by thermal reduction reaction;
• wherein the drying is performed under a temperature of 20˜40° C., and separating and collecting the molten salt media and waste cemented carbide nanopowder.