Process for refining raw copper material containing copper sulfide mineral

Abstract

A process for refining a raw copper material containing a copper sulfide mineral, e.g., chalcopyrite, by the hydrometallurgical process which can leach copper out of the raw material at a high extraction while suppressing oxidation of sulfur, recover it in the monovalent state by electrolysis and, at the same time, recover a concomitant valuable metal while minimizing production of wastes, e.g., leaching residue, as far as possible. The process for refining a raw copper material containing a copper sulfide mineral, comprising a chlorine-aided leaching step for leaching the raw copper material in the presence of chlorine to produce the leaching product liquor containing the copper ion, copper ion reduction step for reducing the leaching product liquor in the presence of a reductant to produce the reduction product liquor containing the cuprous ion, solvent extraction step for treating the reduction product liquor to produce the stripping product liquor containing the copper and raffinate, copper electrowinning step for electrolyzing the stripping product liquor to produce the electrolytic copper, solution purification step for treating the raffinate to produce the purified solution and iron recovery step for treating the purified solution to recover the iron-containing solid therefrom.

What is claimed is:  
     
         1 . A process for refining raw copper material containing copper sulfide mineral characterized by a hydrometallurgical process for recovering copper and a concomitant valuable metal from a raw copper material containing a copper sulfide mineral, comprising: 
 (1) a chlorine-aided leaching step for leaching the raw copper material in the presence of chlorine in an acidic, aqueous chloride solution to produce the leaching product liquor containing the copper ion and residue containing elemental sulfur by leaching copper in the acidic solution,    (2) a copper ion reduction step for reducing the leaching product liquor in the presence of a reductant to produce the reduction product liquor containing the cuprous ion,    (3) a solvent extraction step for extracting copper with the aid of solvent from the reduction product liquor, and stripping loaded solvent to produce the stripping product liquor containing the cuprous ion and raffinate containing the ferrous ion,    (4) a copper electrowinning step for electrolyzing the stripping product liquor to produce the electrolytic copper and spent electrolyte, and    (5) an iron electrowinning step for electrolyzing the raffinate to produce the electrolytic iron and iron spent electrolyte composed of the aqueous iron chloride solution.    
     
     
         2 . The process according to  claim 1  for refining a raw copper material containing a copper sulfide mineral, wherein said chlorine-aided leaching step is effected by blowing chlorine gas into said acidic, aqueous chloride solution.  
     
     
         3 . The process according to  claim 1  for refining a raw copper material containing a copper sulfide mineral, wherein said chlorine-aided leaching step is effected at a slurry concentration of 100 to 400 g/L, leaching temperature of 100 to 110° C. and oxidation-reduction potential of 500 to 600 mV (based on an Ag/AgCl electrode).  
     
     
         4 . The process according to  claim 1  for refining a raw copper material containing a copper sulfide mineral, wherein said chlorine-aided leaching step is controlled in such a way to have a final chloride ion concentration of 250 to 400 g/L in the acidic, aqueous chloride solution.  
     
     
         5 . The process according to  claim 1  for refining a raw copper material containing a copper sulfide mineral, wherein said copper ion reduction step uses the copper sulfide mineral as the reductant.  
     
     
         6 . The process according to  claim 5  for refining a raw copper material containing a copper sulfide mineral, wherein said copper sulfide mineral is treated under heating at the atmospheric pressure in the leaching product liquor to produce the reduction product liquor and residue containing elemental sulfur.  
     
     
         7 . The process according to  claim 6  for refining a raw copper material containing a copper sulfide mineral, wherein said copper sulfide mineral is a copper concentrate mainly composed of chalcopyrite, prepared to have an average particle diameter (D50) of 0.5 to 60 μm, and temperature at which the leaching product liquor is reduced is 90 to 110° C. and, at the same time, is at least the temperature level (A) given by the following formula 1: 
         A (° C.)=6.79×Ln( B )+81.5  Formula 1 
       (wherein, B is an average particle diameter (D50, μm), determined by the Microtrac analyzer, at a volumetric cumulative frequency of 50% of the copper concentrate).  
     
     
         8 . The process according to  claim 6  for refining a raw copper material containing a copper sulfide mineral, wherein said copper sulfide mineral is a copper concentrate mainly composed of chalcopyrite, prepared to have an average particle diameter (D50) of 0.5 to 60 μm, and temperature at which the leaching product liquor is reduced is 90 to 110° C. and, at the same time, is at least the temperature level (A) given by the following formula 2: 
         A (° C.)=7.04×Ln( B )+95.2  Formula 2 
       (wherein, B is an average particle diameter (D50, μm), determined by the Microtrac analyzer, at a volumetric cumulative frequency of 50% of the copper concentrate).  
     
     
         9 . The process according to  claim 6  for refining a raw copper material containing a copper sulfide mineral, wherein said residue is recycled back as a raw copper material to the chlorine-aided leaching step.  
     
     
         10 . The process according to  claim 1  for refining a raw copper material containing a copper sulfide mineral, wherein said solvent extraction step uses an organic solvent containing a solvating extractant for solvent extraction.  
     
     
         11 . The process according to  claim 10  for refining a raw copper material containing a copper sulfide mineral, wherein said organic solvent contains said solvating extractant at 40% by volume or more.  
     
     
         12 . The process according to  claim 1  for refining a raw copper material containing a copper sulfide mineral, wherein an aqueous solution for stripping in said solvent extraction step contains copper at 70 g/L or less and chlorine ion at 50 to 350 g/L.  
     
     
         13 . The process according to  claim 1  for refining a raw copper material containing a copper sulfide mineral, wherein said stripping is effected at 40 to 90° C. in said solvent extraction step.  
     
     
         14 . The process according to  claim 1  for refining a raw copper material containing a copper sulfide mineral, wherein said copper electrowinning step is effected in an electrolysis tank composed of a cathode chamber and anode chamber separated from each other by a diaphragm, characterized in that said stripping product liquor containing the cuprous ion, discharged from said solvent extraction step, is supplied to the cathode chamber to electrowin copper on the cathode, said iron spent electrolyte composed of an aqueous iron chloride solution, discharged from said iron electrowinning step, is supplied to the anode chamber for anodic oxidation, and the solution being supplied to the anode chamber is prevented from flowing into the cathode chamber through the diaphragm.  
     
     
         15 . The process according to  claim 14  for refining a raw copper material containing a copper sulfide mineral, wherein water permeates through said diaphragm at 0.04 to 0.15 L/m 2 ·s.  
     
     
         16 . The process according to  claim 14  for refining a raw copper material containing a copper sulfide mineral, wherein said cathode and anode chambers in said electrolysis tank are structured in such a way that a solution is charged and discharged separately in each chamber, and the solution level is kept higher in said cathode chamber than in said anode chamber.  
     
     
         17 . The process according to  claim 14  for refining a raw copper material containing a copper sulfide mineral, wherein the spent catholyte is recycled back as the aqueous solution for stripping to said solvent extraction step, and the spent anolyte is recycled back as the leachate to said chlorine-aided leaching step.  
     
     
         18 . The process according to  claim 1  for refining a raw copper material containing a copper sulfide mineral, wherein said iron electrowinning step is effected in an electrolysis tank composed of an anode chamber and cathode chamber separated from each other by a filter cloth, characterized in that the iron ion is supplied to the anode chamber at a rate at least twice as high as that for the iron ion deposited on the cathode in order to decrease cell voltage.  
     
     
         19 . The process according to  claim 1  for refining a raw copper material containing a copper sulfide mineral, wherein a solution purification step is included upstream of said iron electrowinning step to purify said raffinate from said solvent extraction step, which produces the purified solution and precipitate product.  
     
     
         20 . The process according to  claim 19  for refining a raw copper material containing a copper sulfide mineral, wherein said raffinate from said solvent extraction step is purified in said solution purification step by a treatment method selected from the group consisting of sulfidation, cementation and neutralization.  
     
     
         21 . The process according to  claim 1  for refining a raw copper material containing a copper sulfide mineral, wherein said residue containing elemental sulfur, discharged from said chlorine-aided leaching step, is distilled in an inert atmosphere to be separated into the condensed sulfur and residue containing a concomitant precious metal, after evaporating sulfur.  
     
     
         22 . The process according to  claim 1  for refining a raw copper material containing a copper sulfide mineral, wherein said electrolytic copper produced in said copper electrowinning step is used as the anode to be refined by electrolysis and separated into the high-purity, electrolytic copper and silver-containing slime.