METHOD OF UTILIZATION OF GALVANIC PROCESS SLUDGE Russian patent published in 2003 - IPC

FIELD: utilization of galvanic process sludge. SUBSTANCE: proposed method includes stages of leaching, regeneration, filtration and decontamination; prior to leaching, sludge is subjected to galvanic activation by water at high pressure, up to 15 Mpa; leaching of copper, nickel and zinc is performed in succession in one apparatus first with hydrochloric acid solution at concentration of 0.3-0.5 m/l and then in ammonia chloride solution of the composition, m/l: 0.3-0.5 NH₄Cl + 3.0-4.0 NH₄OH, which is formed at addition of excessive ammonia water into first solution. Proposed method ensures content of admixtures in separated metals. EFFECT: enhanced efficiency; waste-free process. 2 cl, 1 dwg