Extraction of contaminant metals from dumped metacolloid ores in order to reduce their hazardousness

Abstract

Problems of human and environmental protection from discharges formed in out-of-balance ores dumped from nonferrous metallurgy were considered. To the most hazardous dumps belong those of metacolloid ores, discharges from which are contaminated with copper, zinc, iron, and also indium and cadmium. It was found that the most effective way to preclude the contamination is by using heap leaching of contaminant metals from ores in the chemical reclamation of the dumps. Mathematical dependences of the leaching rate of easily soluble compounds of metals (copper, zinc, indium, and cadmium) from metacolloid ores on the main technological factors of the process: sulfuric acid concentration, ore spraying density, and oxidation interval between sprayings were determined, the optimal process modes were found, and the cost-efficient production of metals in reclamation of dumps of this kind to a state in which they hardly contaminate the environment was calculated.