TECHNOLOGY PROCESSING WASTE OF HARD ALLOYS Russian patent published in 2002 - IPC

FIELD: hydraulic metallurgy of refractory metals, electrochemical processing of waste of hard alloys containing wolfram. SUBSTANCE: technology processing waste of hard alloys includes anode dissolution of waste in electrolyte based on hydrochloric or sulfuric acid. Anode dissolution is carried out under condition of asymmetric reversible current with exposure to forward electric current with periodic change-over of direction of current to backward direction. Process is conducted with concentration of hydrochloric or sulfuric acid equal to 30.0-150.0 g/l; duration of action of backward current τ_b=0.5-2.0 s; ratio of forward current to backward current τ_f/τ_b= 5.0-15.0; density of forward current j_f=1.0-5.0 kA/sq.m and ratio of backward current to forward current j_b/j_f=0.5-2.0, where τ_f is duration of action of forward current, s; τ_b is duration of action of backward current, s; j_f is density of forward current, kA/sq.m; j_b is density of backward current, kA/sq.m. EFFECT: enhanced productivity of process of electrolysis, increased current efficiency, diminished usage of reagents and improved sanitary and hygiene conditions of work. 2 tbl