Copper ores hydrochloric acid leaching

Falconbridge Also called the matte leach process. A process for extracting copper and nickel from matte (a sulfide ore that has been roasted to remove most of the sulfur). Most of the nickel is leached out with hydrochloric acid and recovered as nickel chloride crystals. The leach residue is roasted and leached with sulfuric acid to dissolve the copper. The process has been operated in Canada and Norway since 1970. 

A process using a mixture of sulfuric acid and sodium chloride to produce hydrochloric acid as the leaching reagent for oxidized copper ore has been described by Silo (Si 6). The cupric chloride is reacted with calcium carbonate powder derived from powdered sea shells to precipitate the copper as a pulp. The leaching solution is regenerated by the addition of sulfuric acid to the residual solution from the precipitation process. 

Falconbridge process A selective leaching process used to extract copper and nickel from a sulphide ore containing nickel, copper, and other precious metals that has been roasted to remove the sulphur known as matte. The nickel is removed using hydrochloric acid and recovered as nickel chloride crystals. The residue is then leached with sulphuric... 

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