Behandlung von Kupfersulfidkonzentraten

摘要

A hydrometallurgical method comprising a leaching operation is provided for recovering copper from particulate copper sulfide flotation concentrate containing at least about 20% copper by weight, a significant portion of the copper in the copper sulfide concentrate being in the cuprous state. The copper sulfide flotation concentrate in the finely divided state is subjected to leaching with an alkaline solution of ammonia plus ammonium sulfate of concentration ranging from about 30 gpl to 150 gpl of ammonia and about 25 gpl to 200 gpl of ammonium sulfate at a temperature ranging from about 10 DEG C to 95 DEG C, preferably about 20 DEG C to 40 DEG C, the amount of sulfide concentrate in the leaching solution ranging from about 25 gpl to 500 gpl proportioned at least stoichiometrically to the ammonia concentration of the leaching solution. The sulfide concentrate is leached under substantially ambient pressure while continuously aerating the solution for a time at least sufficient to dissolve the cuprous copper and oxidize it to the cupric state while avoid or substantially minimizing the oxidation of sulfide sulfur to sulfate, and thereby obtain a filtrate containing at least about 15% of the total amount of copper in the concentrate and provide a washed residue containing at least about 20% copper by weight comprised substantially of cupric sulfide. The copper in the leaching solution after further processing is subsequently recovered by electrowinning. The residue can be further treated in a smelter to recover copper therefrom or upgraded by subjecting the residue to conventional flotation and provide a secondary flotation concentrate containing at least about 30% by weight of copper.