AbstractA critical appraisal has been made of methods that have been proposed for the hydro metallurgical treatment of chalcopyrite concentrates. Those methods in which the primary breakdown of chalcopyrite is effected by leachants are discussed. Methods in which leaching is preceded by pyrometal-lurgical decomposition of the mineral include selective sulphation and nonoxidizing treatments in which the ratios of copper, iron and sulphur are changed. No process has yet been found that can replace conventional pyrometallurgical processing, although several have reached the pilot plant stage. The incentives for devising an economic hydrometallurgical process for extracting copper from sulphide ores are the avoidance of air pollution and the possibility of recovering iron, elemental sulphur and other nonferrous metals. Resume Une appreciation critique a ete faite des methodes proposees pour le traitement hydrometallurgique des concentres de chalcopyrite. Les methodes par lesquelles la deecomposition originale...