US 5,431,788 A · Chloride assisted hydrometallurgical copper extraction

Abstract

A process for the extraction of copper from a sulphide copper ore or concentrate comprises subjecting the ore or concentrate to a first leaching at an elevated temperature and pressure in the presence of oxygen and a lixiviant which comprises an acidic solution of chloride and bisulphate or sulphate ions to produce an insoluble basic copper sulphate. The basic copper sulphate so produced is leached in a second leaching preferably at atmospheric pressure with an acidic sulphate solution to dissolve the basic copper salt to produce a leach liquor containing copper sulphate in solution. The resulting leach liquor is subjected to solvent extraction to produce a copper concentrate solution and a raffinate comprising protons and bisulphate or sulphate ions in solution. Protons, and bisulphate or sulphate ions are extracted from the raffinate to produce a sulphuric acid solution which sulphuric acid solution is then recycled to the first leaching at elevated pressure and temperature to serve as a source of bisulphate or sulphate ions in the lixiviant. According to a preferred embodiment, the extraction of the protons and bisulphate or sulphate ions from the raffinate is effected by means of an electrodialysis process. In alternative embodiments copper sulphate is also extracted from the raffinate and recycled to the first leaching step or alternatively a source of bisulphate or sulphate ions, such as a hydrolyzable metal sulphate, is introduced from another source.

Claims16

Dependent claims

A process for the extraction of copper from a sulphide copper ore or concentrate, comprising the steps of:

subjecting the ore or concentrate to a first leaching in the presence of oxygen and a lixiviant comprising an acidic solution of chloride and bisulphate or sulphate ions to produce an insoluble basic copper salt;
leaching the basic copper salt produced by said first leaching step in a second leaching with an acidic sulphate solution to dissolve the basic copper salt to produce a leach liquor containing copper sulphate in solution;
subjecting said leach liquor to a solvent extraction process to produce a copper concentrate solution and a raffinate comprising protons and bisulphate or sulphate ions in solution;
extracting protons and bisulphate or sulphate ions from said raffinate to produce a sulphuric acid solution;
and
recycling said sulphuric acid solution to said first leaching to serve as a source of said bisulphate or sulphate ions in said lixiviant.

3 more elements

A process for the extraction of copper from a sulphide copper ore or concentrate, comprising the steps of:

subjecting the ore or concentrate to a first leaching in the presence of oxygen and a lixiviant comprising an acidic solution of chloride and bisulphate or sulphate ions to produce an insoluble basic copper salt;
leaching the basic copper salt produced by said first leaching step in a second leaching with an acidic sulphate solution to dissolve the basic copper salt to produce a leach liquor containing copper sulphate in solution;
subjecting said leach liquor to a solvent extraction process to produce a first copper concentrate solution and a raffinate comprising protons, copper ions and bisulphate or sulphate ions in solution;
extracting copper ions and bisulphate or sulphate ions from said raffinate to produce a second copper concentrate solution;
recycling said second copper concentrate solution to said first leaching to serve as a source of said bisulphate or sulphate ions in said lixiviant;
and
subjecting said first copper concentrate solution to electrowinning to recover copper values therefrom.

4 more elements

Dependencies are inferred from the claim text.

Chloride assisted hydrometallurgical copper extraction

Life of this patent

Chloride assisted hydrometallurgical copper extraction

Life of this patent

Abstract

Claims16