Study on the Electrochemical Mechanism of the Comprehensive Recovery of Valuable Components from Spent Cemented Carbide

Spent cemented carbide contains a large number of valuable metals including tungsten and cobalt. To reasonably and effectively utilize the secondary resources of spent cemented carbide, Co and WO3 were recovered from spent cemented carbide by a combination of low-temperature electrochemical separation and high-temperature calcination. In a low-temperature (298 K) aqueous acid solution, a three-electrode system was used for electrochemical testing. The results show that on stainless steel cathodes, the deposition potential of Co(II) was between -0.6 and -0.5 V (vs SCE). Electrodeposition was controlled by diffusion and was irreversible. The diffusion coefficient of Co(II) was 7.12 x10(-7) cm(2) S-1. The electrodeposition products were characterized by XRD and SEM, and the results showed that anode mud H2WO4 formed an orthorhombic crystal system. This H2WO4 was decomposed into WO3 by high-temperature calcination. The combination of low-temperature electrochemical separation and high-temperature calcination thus serves as an effective way to recover and separate valuable metals from spent alloys.