TREATMENT PROCESS OF HEAVY METAL IN WASTE

摘要

PROBLEM TO BE SOLVED: To provide a treatment process of heavy metals in waste which is excellent in recovery effect of lead, zinc and calcium in waste. SOLUTION: This treatment process comprises: subjecting waste containing heavy metals to water washing treatment to obtain a filtrate; adding sulfuric acid, hydrochloric acid, nitric acid or gaseous carbon dioxide to the filtrate, to precipitate the heavy metals in the filtrate as their hydroxides, sulfates or carbonates and to obtain precipitated sludge; subjecting the precipitated sludge to alkali leaching to elute the heavy metals; filtering the leachate to obtain a leachate filtrate; subjecting the leachate filtrate to neutralization and/or sulfiding treatment, to precipitate and recover the heavy metals in the leachate filtrate.