Hydrometallurgical process for the production of copper

Claim 2

A HYDROMETALLURIGICAL PROCESS FOR THE PRODUCTION OF METALLIC COPPER COMPRISING A REDUCTION STAGE IN WHICH MATERIALS CONTAINING COPPER-IRON SULFIDE ORE CONCENTRATES ARE INTRODUCED INTO AN AQUEOUS CHLORIDE SOLUTION CONTAINING CUPRIC CHLORIDE TO SOLUBILIZE PART OF THE COPPER IN SAID MATERIALS AND REDUCE A SUBSTANTIAL PORTION OF THE CUPRIC CHLORIDE TO CUPROUS CHLORIDE, THE TOTAL CHLORIDE ION CONCENTRATION RELATIVE TO THE WATER CONTENT OF SAID CHLORIDE SOLUTION BEING MAINTAINED AT THE DESIRED LEVEL TO MINIMIZE PRECIPITATION OF CUPROUS CHLORIDE IN SAID SOLUTION BY THE ADDITION OF A SALINE METAL CHLORIDE COMPOUND SELECTED FROM THE GROUP CONSISTING OF POTASSIUM CHLORIDE, MAGNESIUM CHLORIDE, AMIXTURE OF MGNESIUM CHLORIDE AND POTASSIUM CHLORIDE; OR A MIXTURE OF ANY OF THE FOREGOING WITH SODIUM CHLORIDE; A COPPER RECOVERY STAGE IN WHICH METALLIC COPPER IS RECOVERED BY REDUCTION OF THE CUPROUS CHLORIDE IN THE SOLUTION FROM THE REDUCTION STAGE; AND IN WHICH CUPRIC CHLORIDE IS REGENERATED; AND AN OXIDATION STAGE COMBINED WITH A REGENERATION-PURGE STAGE TO RETARD SCALING OF EQUIPMENT IN WHICH THE RAFFINATE FROM THE COPPER RECOVERY STAGE IS REACTED WITH OXYGEN TO FORM A SOLUTION CONTAINING FERRIC CHLORIDE WHICH CONCURRENTLY OXIDIZES THE UNREACTED MATERIALS FROM THE REDUCTION STAGE TO SOLUBILIZE SUBSTANTIALLY ALL THE REMAINING COPPER IN THE MATERIALS, THEREBBY FORMING A SOLUTION CONTAINING CUPRIC CHLORIDE AND FERRIC CHLORIDE, WITH THE CONCURRENT PRECIPITATION, BY REACTION OF FERROUS CHLORIDE WITH OXYGEN AND HYDROLYSIS, OF COMPOUNDS INCLUDING THOSE HAVING THHE IRONSULFATE RATIOS OF JAROSITE, TO THEREBY REMOVE A SUBSTANTIAL PORTION OF THE IRON AS WELL AS SULFATE IONS AND OTHER IMPURITIES FROM THE CHLORIDE SOLUTION; AND RECYCLING THE CHLORIDE SOLUTION CONTAINING CUPRIC CHLORIDE TO THE REDUCTION STAGE.

Claim 3

A hydrometallurgical process for the production of metallic copper comprising a reduction stage in which materials containing copper-iron sulfide ore concentrates are introduced into an aqueous chlorIde solution containing cupric chloride to solubilize part of the copper in said materials and reduce a substantial portion of the cupric chloride to cuprous chloride, the total chloride ion concentration relative to the water content of said chloride solution being maintained at the desired level to minimize precipitation of cuprous chloride in said solution by the addition of a saline metal chloride compound selected from the group consisting of potassium chloride, magnesium chloride, a mixture of magnesium chloride and potassium chloride; or a mixture of any of the foregoing with sodium chloride; a copper recovery stage in which metallic copper is recovered by reduction of the cuprous chloride in the solution from the reduction stage; and in which cupric chloride is regenerated; and an oxidation stage combined with a regeneration-purge stage to retard scaling of equipment in which the raffinate from the copper recovery stage is reacted with oxygen to form a solution containing ferric chloride which concurrently oxidizes the unreacted materials from the reduction stage to solubilize substantially all the remaining copper in the materials, thereby forming a solution containing cupric chloride and ferric chloride, with the concurrent precipitation, by reaction of ferrous chloride with oxygen and hydrolysis, of compounds including those having the iron-sulfate ratios of jarosite, to thereby remove a substantial portion of the iron as well as sulfate ions and other impurities from the chloride solution; and recycling the chloride solution containing cupric chloride to the reduction stage.

Claim 4

A hydrometallurgical process for the production of metallic copper comprising a reduction stage in which materials containing copper-iron sulfide ore concentrates are introduced into an aqueous chlorIde solution containing cupric chloride to solubilize part of the copper in said materials and reduce a substantial portion of the cupric chloride to cuprous chloride, the total chloride ion concentration relative to the water content of said chloride solution being maintained at the desired level to minimize precipitation of cuprous chloride in said solution by the addition of a saline metal chloride compound selected from the group consisting of potassium chloride, magnesium chloride, a mixture of magnesium chloride and potassium chloride; or a mixture of any of the foregoing with sodium chloride; a copper recovery stage in which metallic copper is recovered by reduction of the cuprous chloride in the solution from the reduction stage; and in which cupric chloride is regenerated; and an oxidation stage combined with a regeneration-purge stage to retard scaling of equipment in which the raffinate from the copper recovery stage is reacted with oxygen to form a solution containing ferric chloride which concurrently oxidizes the unreacted materials from the reduction stage to solubilize substantially all the remaining copper in the materials, thereby forming a solution containing cupric chloride and ferric chloride, with the concurrent precipitation, by reaction of ferrous chloride with oxygen and hydrolysis, of compounds including those having the iron-sulfate ratios of jarosite, to thereby remove a substantial portion of the iron as well as sulfate ions and other impurities from the chloride solution; and recycling the chloride solution containing cupric chloride to the reduction stage.

Claim 5

The process of claim 1 in which the total chloride ion concentration is maintained at a level which will increase the degree of reduction of cupric chloride to cuprous chloride in the reduction stage with minimal loss of copper from solution.

Claim 6

The process of claim 2 in which the chloride ion concentration is maintained near the maximum permitted by the solubility of the saline metal chlorides in the process solution.

Claim 7

The process of claim 3 in which potassium chloride is included in the saline metal chloride addition.

Claim 8

The process of claim 4 in which potassium chloride is included in the saline metal chloride addition in the amount required to achieve the desired purge of as much as substantially all the sulfate ion by precipitation from the solution.

Claim 9

The process of claim 4 in which sodium chloride is selected as the saline metal chloride with which potassium chloride is included.

Claim 10

The process of claim 1 in which the residual iron concentration in the combined oxidation and regeneration-purge stage finally reacted liquor is limited by controlling the inventory of reactive chloride ion in the process liquor.

Claim 11

The process of claim 1 in which the removal of the iron from the chloride solution in the combined oxidation and regeneration-purge stage is limited so as to retain sufficient iron to assure that all copper chloride is present as cupric chloride in the finally reacted liquor.

Claim 12

The process of claim 8 in which metallic copper is recovered by electrolysis in the copper recovery stage and the amount recovered is maintained equivalent to the copper dissolved into the process liquor, with oxidation in the anolyte of the cuprous chloride to cupric chloride, and also oxidation in the anolyte of ferrous chloride to ferric chloride in an amount equivalent to one-third of the residual ferric chloride present in the combined oxidation and regeneration-purge stage finally reacted liquor.

Claim 13

A hydrometallurgical process for the production of metallic copper from copper sulfide ore concentrates containing a substantial proportion of chalcopyrite, comprising a reduction stage in which the ore concentrates are introduced into an aqueous chloride solution containing cupric chloride to solubilize part of the copper in said materials and reduce substantially all of the cupric chloride to cuprous chloride, the total chloride ion concentration of said chloride solution reLative to the water content thereof being maintained, by the addition of a saline metal chloride compound selected from the group consisting of potassium chloride, magnesium chloride, a mixture of any of the foregoing with sodium chloride, in an amount near the maximum permitted by the solubility of the saline metal chlorides in said chloride solution; a copper recovery stage in which metallic copper is recovered by electrolyzing in electrolytic cells the cuprous chloride in the solution from the reduction stage to produce metallic copper in the cathode compartment and to regenerate the cupric chloride in the anode compartment; and an oxidation stage combined with a regeneration-purge stage to retard scaling of equipment in which the raffinate from the copper recovery stage is reacted with oxygen to form a solution containing ferric chloride which concurrently oxidizes the unreacted ore concentrates from the reduction stage to solubilize substantially all the remaining copper in said concentrates, thereby forming a solution containing cupric chloride and minimal residual ferric chloride, with the concurrent precipitation by hydrolysis, of compounds including those having the ironsulfate ratios of jarosite, to thereby remove the excess iron as well as excess sulfate ions and other impurities from the chloride solution; and recycling the chloride solution containing cupric chloride and minimal ferric chloride to the reduction stage.

Claim 14

A hydrometallurgical process for the production of metallic copper from copper sulfide ore concentrates containing a substantial proportion of chalcopyrite, comprising a reduction stage in which the ore concentrates are introduced into an aqueous chloride solution containing cupric chloride to solubilize part of the copper in said materials and reduce substantially all of the cupric chloride to cuprous chloride, the total chloride ion concentration of said chloride solution reLative to the water content thereof being maintained, by the addition of a saline metal chloride compound selected from the group consisting of potassium chloride, magnesium chloride, a mixture of any of the foregoing with sodium chloride, in an amount near the maximum permitted by the solubility of the saline metal chlorides in said chloride solution; a copper recovery stage in which metallic copper is recovered by electrolyzing in electrolytic cells the cuprous chloride in the solution from the reduction stage to produce metallic copper in the cathode compartment and to regenerate the cupric chloride in the anode compartment; and an oxidation stage combined with a regeneration-purge stage to retard scaling of equipment in which the raffinate from the copper recovery stage is reacted with oxygen to form a solution containing ferric chloride which concurrently oxidizes the unreacted ore concentrates from the reduction stage to solubilize substantially all the remaining copper in said concentrates, thereby forming a solution containing cupric chloride and minimal residual ferric chloride, with the concurrent precipitation by hydrolysis, of compounds including those having the ironsulfate ratios of jarosite, to thereby remove the excess iron as well as excess sulfate ions and other impurities from the chloride solution; and recycling the chloride solution containing cupric chloride and minimal ferric chloride to the reduction stage.

Claim 15

The process of claim 10 in which the metallic copper produced at the cathodes in the electrolysis stage is maintained substantially equivalent to the copper dissolved into the chloride solution and will therefore be accompanied by the oxidation of the cuprous chloride to cupric chloride in the anolyte, and also oxidation of ferrous chloride to ferric chloride in the anolyte in an amount equivalent to one-third of the residual ferric chloride present in the combined oxidation and regeneration-purge stage finally reacted liquor.

Claim 16

A hydrometallurgical process for the production of metallic copper comprising: A. Reacting at about 107C materials containing principally fresh chalcopyrite ore concentrates with a cupric chloride solution containing a limited amount of ferric chloride, to thereby reduce a substantial portion of the cupric chloride to cuprous chloride and to produce ferrous chloride, said cupric chloride solution containing sufficient sodium chloride and potassium chloride to maintain the total chloride concentration, related to water, near the maximum permitted by the solubility of the sodium and potassium chlorides in the process solution. B. Electrolyzing in electrolytic cells the cuprous chloride in the solution from step A to produce metallic copper in the cathode compartment and to regenerate the cupric chloride in the anode compartment; C. Reacting with oxygen at a temperature between about 107C and about 159*C and at a pressure between atmospheric pressure and about 60 psig the ferrous chloride in the spent electrolyte in the presence of regenerated cupric chloride to regenerate ferric chloride and cupric chloride which concurrently oxidize the unreacted ore concentrates from step A to solubilize substantially all the remaining copper in the ore concentrates, thereby forming a solution containing cupric chloride and some limited ferric chloride, with the concurrent precipitation, by hydrolysis, of excess iron as potassium jarosite, to thereby remove excess iron and excess sulfate ions from the cupric chloride solution as well as removing other impurities; and D. Recycling the cupric chloride solution containing a limited amount of iron chloride from step C to step A.

Claim 17

A hydrometallurgical process for the production of metallic copper comprising: A. Reacting at about 107C materials containing principally fresh chalcopyrite ore concentrates with a cupric chloride solution containing a limited amount of ferric chloride, to thereby reduce a substantial portion of the cupric chloride to cuprous chloride and to produce ferrous chloride, said cupric chloride solution containing sufficient sodium chloride and potassium chloride to maintain the total chloride concentration, related to water, near the maximum permitted by the solubility of the sodium and potassium chlorides in the process solution. B. Electrolyzing in electrolytic cells the cuprous chloride in the solution from step A to produce metallic copper in the cathode compartment and to regenerate the cupric chloride in the anode compartment; C. Reacting with oxygen at a temperature between about 107C and about 159*C and at a pressure between atmospheric pressure and about 60 psig the ferrous chloride in the spent electrolyte in the presence of regenerated cupric chloride to regenerate ferric chloride and cupric chloride which concurrently oxidize the unreacted ore concentrates from step A to solubilize substantially all the remaining copper in the ore concentrates, thereby forming a solution containing cupric chloride and some limited ferric chloride, with the concurrent precipitation, by hydrolysis, of excess iron as potassium jarosite, to thereby remove excess iron and excess sulfate ions from the cupric chloride solution as well as removing other impurities; and D. Recycling the cupric chloride solution containing a limited amount of iron chloride from step C to step A.

Claim 18

A hydrometallurgical process for the production of metallic copper comprising an oxidation stage in which materials containing copper-iron sulfide ore concentrates are oxidized in a solution containing iron chloride and cupric chloride until there is substantial solubilization of thE copper content of said materials in the form of cupric chloride, a reduction stage separate from the oxidation stage in which at least a substantial portion of the cupric chloride in the solution from the oxidation stage is reduced to cuprous chloride, said cupric chloride solution containing sufficient sodium chloride and potassium chloride to maintain the total chloride concentration, related to water, near the maximum permitted by the solubility of the sodium and potassium chlorides in the process solution; an electrolysis stage in which metallic copper is recovered and cupric chloride is regenerated by electrolysis of the cuprous chloride solution from the reduction stage, and a regeneration-purge stage separate from the reduction and electrolysis stages in which the ferrous chloride in the solution from the electrolysis stage is reacted with oxygen in the presence of the regenerated cupric chloride to regenerate the ferric chloride required in the oxidation stage and to precipitate, by hydrolysis, compounds including potassium jarosite to thereby control the concentration in the process solution of iron as well as sulfate ions and remove other impurities from the solution.

Claim 19

A hydrometallurgical process for the production of metallic copper comprising an oxidation stage in which materials containing copper-iron sulfide ore concentrates are oxidized in a solution containing iron chloride and cupric chloride until there is substantial solubilization of thE copper content of said materials in the form of cupric chloride, a reduction stage separate from the oxidation stage in which at least a substantial portion of the cupric chloride in the solution from the oxidation stage is reduced to cuprous chloride, said cupric chloride solution containing sufficient sodium chloride and potassium chloride to maintain the total chloride concentration, related to water, near the maximum permitted by the solubility of the sodium and potassium chlorides in the process solution; an electrolysis stage in which metallic copper is recovered and cupric chloride is regenerated by electrolysis of the cuprous chloride solution from the reduction stage, and a regeneration-purge stage separate from the reduction and electrolysis stages in which the ferrous chloride in the solution from the electrolysis stage is reacted with oxygen in the presence of the regenerated cupric chloride to regenerate the ferric chloride required in the oxidation stage and to precipitate, by hydrolysis, compounds including potassium jarosite to thereby control the concentration in the process solution of iron as well as sulfate ions and remove other impurities from the solution.

Claim 20

The process of claim 13 in which the total chloride ion concentration is maintained at a level which will increase the degree of reduction of cupric chloride to cuprous chloride in the reduction stage with minimal loss of copper from solution.

Claim 21

The process of claim 13 in which the desired purge of the excess sulfate ion by precipitation is achieved by controlling the amount of potassium chloride which is included in the process solution.