The article presents the results of studies on the purification of sludge obtained by converting waste tungsten carbide and cobalt hard alloys into a cobalt solution with electrolysis to the state of pure tungsten carbide powders. Conducted scientific and practical studies show that the original sludge contains Al, Fe, Ni, Mo, Hf, V, Hg and other harmful metal impurities, as well as a large amount of SiO2. The use of powders containing these metals and metal oxides in the production of hard alloys without purification worsens the physical and mechanical properties of the resulting parts. The research used a two-stage sludge purification technology and obtained tungsten carbide powders with a purity of 99.9%.