Recovery of metals from ores

Abstract

A process for using an aqueous oxidizing solution includes at least steps of formulating the aqueous oxidizing solution by addition of ingredients to water; a metal solubilization step of oxidizing and thereby rendering soluble a desired at least one metal from a ground amount of ore in suspension; collecting a pregnant liquor from the suspension; and selectively removing at least a portion of the at least one metal from the liquor while at a pH of less than 3, such that any remaining liquid is a recyclable liquor. The aqueous oxidizing solution has a pH of less than 0.7 primarily as a result of the presence of at least one strong acid and persulphate anions. The aqueous oxidizing solution contains anions selected from a group consisting of chloride, bromide, iodide and nitrate.

1 - 11 . (canceled) 
     
     
         12 . An aqueous oxidizing solution comprising:
 a pH of less than 0.7;   at least one strong acid;   at least 0.05% by weight persulphate anions; and   0.8-2.8M of anions selected from a group consisting of chloride, bromide, iodide and nitrate.   
     
     
         13 . The aqueous oxidizing solution of  claim 12 , further comprising at least one compound selected from the group consisting of hydrogen peroxide and ozone. 
     
     
         14 . The aqueous oxidizing solution of  claim 12 , further comprising ozone generated from exposure to ultraviolet light. 
     
     
         15 . The aqueous oxidizing solution of  claim 12 , further comprising at least one compound selected from the group consisting of hydrogen peroxide and ozone present in a molar concentration of between 10 to 21 μM. 
     
     
         16 . The aqueous oxidizing solution of  claim 12 , comprising:
 hydrochloric acid,   a persulphate selected from the group consisting of sodium persulphate, potassium persulphate, and ammonium persulphate,   hydrogen peroxide,   ozone, and   water.   
     
     
         17 . The aqueous oxidizing solution of  claim 12 , comprising:
 3-10% by weight of hydrochloric acid;   0.05 to 2% of a persulphate selected from the group consisting of sodium persulphate, potassium persulphate and ammonium persulphate;   0.1-0.3% by volume of commercial strength (30%) hydrogen peroxide;   ozone in an amount of about 0.5 to 1 mg/liter made by ultraviolet irradiation of oxygen; and   water.   
     
     
         18 . The aqueous oxidizing solution of  claim 12 , comprising:
 8.4% by volume of concentrated hydrochloric acid;   0.09% by weight of sodium persulphate, potassium persulphate, or ammonium persulphate;   0.18% by weight of sodium bromide;   0.16% by volume of commercial strength hydrogen peroxide;   ozone at about 0.75 mg/liter made by ultraviolet irradiation of oxygen; and   water.   
     
     
         19 . A process for using an aqueous oxidizing solution comprising at least steps of:
 formulating the aqueous oxidizing solution by addition of ingredients to water, wherein the aqueous oxidizing solution has a pH of less than 0.7 primarily as a result of the presence of at least one strong acid, at least 0.05% by weight persulphate anions, wherein the aqueous oxidizing solution contains 0.8-2.8M of anions selected from a group consisting of chloride, bromide, iodide and nitrate;   a metal solubilization step of oxidizing and thereby rendering soluble a desired at least one metal from a ground amount of ore in suspension;   collecting a pregnant liquor from the suspension; and   selectively removing at least a portion of the at least one metal from the liquor while at a pH of less than 3, such that any remaining liquid is a recyclable liquor.   
     
     
         20 . The process of  claim 19 , wherein prior to the metal solubilization step, the ore is ground such that at least 95% of the ground ore can be passed through a 0.1 mm diameter sieve. 
     
     
         21 . The process of  claim 19 , wherein the ground ore is introduced into the solution to arrive at an amount of at least 5% by weight of ore in the suspension. 
     
     
         22 . The process of  claim 19 , wherein the ground ore is introduced into the solution to arrive at an amount of at least 10% by weight of ore in the suspension. 
     
     
         23 . The process of  claim 19 , wherein the aqueous oxidizing solution further comprises at least one compound selected from the group consisting of hydrogen peroxide and ozone present in a molar concentration of between 10 to 21 μM. 
     
     
         24 . The process of  claim 19 , wherein a pH of the aqueous oxidizing solution is maintained at less than 3 throughout the process; and includes a further step of holding the recyclable liquor ready for return to the formulating step. 
     
     
         25 . The process of  claim 19 , wherein the metal solubilization step takes between 1 and 24 hours to complete. 
     
     
         26 . The process of  claim 19 , wherein a pH of the aqueous oxidizing solution is maintained at less than 3 throughout the process; and further comprises holding the recyclable liquor ready for return to the formulating step; and recycling the recyclable liquor into substantially the aqueous oxidizing solution by addition of those ingredients consumed in the process. 
     
     
         27 . The process of  claim 19 , wherein the formulation step comprises a sub-step of bubbling ozone into the solution and recirculating the solution past a source of ultraviolet light. 
     
     
         28 . An apparatus for performing the process of  claim 19  wherein the apparatus provides a plurality of paths for separate extraction of more than one metal from the ore in a series of steps; each path including at least: a pregnant liquor storage tank; metal extraction apparatus; and a recyclable liquor storage tank. 
     
     
         29 . A process for using an apparatus for performing the process of  claim 19  wherein the apparatus provides a plurality of paths for separate extraction of more than one metal from the ore in a series of steps; each path including at least: a pregnant liquor storage tank; metal extraction apparatus; and a recyclable liquor storage tank, wherein the process for using the apparatus comprises providing a series of oxidizing solutions wherein a pH is reduced for each path within the series and a reduction potential (E h ) is increased for each path within the series, thereby exposing the ore in suspension to a series of increasingly acidic and increasingly oxidizing solutions.