Copper processing method

Abstract

A method of processing a copper-containing source material is provided whereby an aqueous acidic leach solution of the copper-containing source material is formed and then contacted with a pH increasing agent to thereby cause the precipitation of a copper-containing intermediate. The copper-containing intermediate can then be collected and exposed to a high temperature treatment, such as would be encountered in smelter or converter operations.

1 . A method of processing a copper-containing source material including the steps of:
 (a) providing an aqueous acidic leach solution of the copper-containing source material;   (b) introducing a pH increasing agent into the acidic leach solution to cause the precipitation of a copper-containing intermediate; and   (c) collecting the copper-containing intermediate and exposing it to a high temperature treatment, optionally transporting the copper-containing intermediate to another location prior to its exposure to the high temperature treatment   to thereby process the copper-containing source material.   
     
     
         2 . The method of  claim 1  wherein the copper-containing source material is a copper-containing ore, copper smelter slag, copper-containing tailings, copper concentrate or a copper-containing process intermediate or waste product. 
     
     
         3 . The method of  claim 2  wherein the copper-containing ore is selected from a copper sulphide or copper oxide ore. 
     
     
         4 . The method of  claim 1  wherein the aqueous acidic leach solution is formed from an acid selected from the group consisting of sulphuric, nitric and hydrochloric acids. 
     
     
         5 . The method of  claim 1  wherein the pH increasing agent is selected from the group consisting of calcium oxide, calcium carbonate, calcium hydroxide, calcium ferrite, magnesium oxide, magnesium carbonate, magnesium hydroxide, sodium carbonate, sodium hydroxide, dolomite and materials containing one or more of these compounds. 
     
     
         6 . (canceled) 
     
     
         7 . The method of  claim 1  wherein the pH of the acidic leach solution of the copper source material is raised by the pH increasing agent to between about 4.0 to about 9.0. 
     
     
         8 . The method of  claim 1  wherein the high temperature treatment is at a temperature of between about 1000° C. to about 1400° C. 
     
     
         9 . The method of  claim 1  wherein the high temperature treatment is carried out in a smelter or converter. 
     
     
         10 . The method of  claim 9  wherein when the high temperature treatment is performed in a converter then an oxygen-containing gas and a sulphide compound are introduced into the heating environment. 
     
     
         11 . The method of  claim 1  further including a step, prior to step (b), of introducing an effective amount of a pH increasing agent into the acidic leach solution to cause the precipitation of an iron-containing compound without any substantial precipitation of the copper containing-intermediate. 
     
     
         12 . The method of  claim 11  wherein the pH increasing agent will raise the pH of the acidic leach solution to be between about 1.5 to 3.5 to cause the precipitation of an iron-containing compound without any substantial precipitation of the copper containing-intermediate. 
     
     
         13 . The method of  claim 1  further including the step of exposing the copper-containing intermediate to a separation step prior to the high temperature treatment. 
     
     
         14 . The method of  claim 13  wherein, when the pH increasing agent is lime and/or limestone, the separation step is the separation of precipitated gypsum from the copper-containing intermediate based upon a difference in the particle sizes thereof. 
     
     
         15 . The method of  claim 1  further including the step, prior to step (c), of heating the copper-containing intermediate to a temperature between 200° C. to 800° C. to provide a more concentrated copper-containing intermediate to introduce to step (c). 
     
     
         16 . The method of  claim 1  wherein the copper-containing source material is a copper sulphide-containing source material and the method further includes the step (a-i) of exposing the copper sulphide-containing source material to an oxidative roast, prior to its exposure to the leach solution, to form a calcined copper-containing source material. 
     
     
         17 . The method of  claim 16  wherein the oxidative roast is performed at a temperature of between about 500° C. to about 950° C. 
     
     
         18 . The method of  claim 16  further including the step (a-ii) of contacting the calcined copper-containing source material with a leach solution to form the aqueous acidic leach solution of step (a). 
     
     
         19 . The method of  claim 18  wherein the aqueous acidic leach solution after substantial dissolution of the calcined copper-containing source material has a pH of between about 2 to about 5. 
     
     
         20 . A method of processing a copper sulphide-containing source material including the steps of:
 (a-i) exposing the copper sulphide-containing source material to an oxidative roast to form a calcined copper-containing source material;   (a-ii) contacting the calcined copper containing source material with a leach solution to form an acidic copper-containing leach solution;   (b) introducing a pH increasing agent into the acidic copper-containing leach solution to cause the precipitation of a copper-containing intermediate; and   (c) collecting the copper-containing intermediate and exposing it to a high temperature treatment,   
       to thereby process the copper sulphide-containing source material. 
     
     
         21 . The method of  claim 20  further including the step (aa-i) of contacting the copper sulphide-containing source material under non-oxidising conditions, prior to the oxidative roast, with an acidic or alkaline solution to leach out select impurities. 
     
     
         22 . (canceled)