Hydrometallurgical System and Process Using an Ion Transport Membrane

Abstract

A hydrometallurgical system and process with a hydrometallurgical processing circuit integrated with an ion transport membrane assembly. The ion transport membrane assembly provide oxygen to the hydrometallurgical processing circuit.

We claim: 
     
         1 . A hydrometallurgical processing system for processing a metal-bearing material, the system comprising:
 an ion transport membrane assembly comprising an ion transport membrane layer and having a feed side and a permeate side where the feed side has an inlet for introducing a first feed gas comprising oxygen and nitrogen into the ion transport membrane assembly and a first outlet for withdrawing a nitrogen-enriched product from the feed side of the ion transport membrane assembly, and where the permeate side has a second outlet for withdrawing an oxygen product from the ion transport membrane assembly; and   a hydrometallurgical processing circuit comprising
 a pre-processing unit operatively disposed to receive a metal-bearing material and selected from a group of units consisting of a grinding unit, a roasting unit, a pressure oxidation unit, a bio-oxidation unit, an upstream leaching unit, and a solution or slurry preparation unit; 
 a downstream leaching unit operatively disposed to receive at least a pre-processed portion of the metal-bearing material from the pre-processing unit; and 
 one or both of an acid production unit and a post-processing unit, the post-processing unit, if present, operatively disposed to receive and adapted to post-process material from the downstream leaching unit; 
 wherein at least one of the pre-processing unit, the downstream leaching unit, the acid production unit, if present, or the post-processing unit, if present, are operatively disposed to receive an oxidant gas containing at least a portion of the oxygen product and/or activated oxygen generated from at least a portion of the oxygen product from the ion transport membrane assembly. 
   
     
     
         2 . The system of  claim 1  wherein the hydrometallurgical processing circuit comprises at least one outlet for an oxygen-containing effluent gas, this outlet operatively connected with one or both of
 the feed side of the ion transport membrane assembly for feeding at least a portion of an oxygen-containing effluent gas from the hydrometallurgical processing circuit to the feed side of the ion transport membrane assembly; and 
 a mixing junction for mixing at least a portion of an oxygen-containing effluent gas from the hydrometallurgical processing circuit with the at least a portion of the oxygen product. 
 
     
     
         3 . The system of  claim 1  wherein the pre-processing unit is a pressure oxidation unit operatively disposed to receive at least a portion of the oxidant gas, and/or the downstream leaching unit is an oxidative leaching unit operatively disposed to receive at least a portion of the oxidant gas. 
     
     
         4 . The system of  claim 1 , wherein
 the pre-processing unit is a grinding unit operatively disposed to receive the metal-bearing material; and   the hydrometallurgical processing circuit comprises at least one further pre-processing unit operatively disposed to receive at least a portion of the ground metal-bearing material from the grinding unit and selected from the group consisting of a pressure oxidation unit, a roasting unit, a bio-oxidation unit, an upstream oxidative leaching unit, and an oxidative solution or slurry preparation unit;   
       wherein at least one of
 (a) the grinding unit is operatively disposed either to receive at least a portion of the oxidant gas for grinding in an oxygen containing gas or liquid or to receive an oxygen-deficient grinding gas containing at least a portion of the nitrogen-enriched product for grinding in an oxygen-deficient environment; 
 (b) the at least one further pre-processing unit is operatively disposed to receive at least a portion of the oxidant gas for at least partial consumption in oxidation; or 
 (c) the downstream leaching unit is operatively disposed to receive at least a portion of the oxidant gas for oxidative leaching. 
 
     
     
         5 . The system of  claim 1  wherein at least one of the pre-processing unit, the downstream leaching unit, or the post-processing unit, the latter if present, comprises an autoclave operatively disposed to receive an autoclave slurry or solution containing one or more metal values of the metal-bearing material and operatively disposed to receive at least a portion of the oxidant gas, the autoclave comprising a gassing system for introducing the at least a portion of the oxidant gas into the autoclave slurry or solution. 
     
     
         6 . The system of  claim 1  wherein the hydrometallurgical processing circuit comprises:
 an autoclave operatively disposed to receive an autoclave slurry or solution containing one or more metal values of the metal-bearing material; and 
 a heat exchanger to heat the autoclave slurry or solution by indirect heat transfer with a heat exchanger feed stream comprising at least a portion of the nitrogen-enriched product and/or at least a portion of the oxidant gas. 
 
     
     
         7 . The system of  claim 1  further comprising a turbine operatively disposed to receive at least a portion of the nitrogen-enriched product from the ion transport membrane assembly, the turbine being a gas turbine, a combustion turbine, or a pressure letdown turbine,
 wherein the turbine is operatively disposed to provide at least a portion of the first feed gas to the ion transport membrane assembly, and/or 
 wherein the system further comprises a generator for producing electric power, the generator operatively connected to the turbine to receive shaft work from the turbine and the hydrometallurgical processing circuit operatively disposed to receive at least a portion of the electric power produced by the generator. 
 
     
     
         8 . The system of  claim 1  further comprising a heat recovery steam generator operatively disposed to receive one or more steam generator feed streams and feed water, the heat recovery steam generator adapted to extract heat from the one or more steam generator feed streams and to produce steam from the feed water, wherein the one or more steam generator feed streams comprise at least a portion of the nitrogen-enriched product from the ion transport membrane assembly and/or a hot off-gas from the hydrometallurgical processing circuit. 
     
     
         9 . The system of  claim 8  wherein a steam generator feed stream is combusted with fuel, the heat recovery steam generator adapted to recover heat from the combustion of the steam generator feed stream with the fuel and/or from at least a portion of a hot combustion product of that combustion. 
     
     
         10 . The system of  claim 8  wherein the heat recovery steam generator is adapted to recover heat from one or more of the following heat sources (i) to (iv):
 (i) at least a portion of the nitrogen-enriched product received as the steam generator feed stream, 
 (ii) a hot off-gas of the hydrometallurgical processing circuit received as the steam generator feed stream or as a further steam generator feed stream, 
 (iii) the combustion of the preceding claim, or 
 (iv) the at least a portion of the hot combustion product of the preceding claim to produce steam from the feed water; 
 wherein the hydrometallurgical processing circuit is operatively disposed to receive at least a portion of the steam from the heat recovery steam generator; and/or 
 wherein the heat recovery steam generator is operatively disposed to receive an oxygen-containing feed gas and adapted to heat the oxygen-containing feed gas by recovering heat from one or more of the heat sources (i) to (iv), the heat recovery steam generator operatively disposed to provide at least a portion of the heated oxygen-containing feed gas to the ion transport membrane assembly. 
 
     
     
         11 . The system of  claim 1  further comprising:
 a hydrogen production unit operatively disposed to receive a hydrogen production feed stream and to provide a hydrogen-containing product wherein the hydrometallurgical processing circuit is operatively disposed to receive at least a portion of the hydrogen-containing product; 
 and at least one of
 a heat exchanger adapted to heat the hydrogen production feed stream by indirect heat transfer with a heat exchanger feed stream comprising at least a portion of the oxygen product and/or at least a portion of the nitrogen-enriched product from the ion transport membrane assembly; or 
 a heat exchanger adapted to heat at least a portion of the first feed gas by indirect heat transfer with a heat exchanger feed stream comprising at least a portion of the hydrogen-containing product and/or a hydrogen production unit flue gas. 
 
 
     
     
         12 . The system of  claim 1  further comprising:
 a hydrogen production unit operatively disposed to receive a hydrogen production feed stream and to provide a hydrogen-containing product; 
 a nitrogen purification unit operatively disposed to receive at least a portion of the nitrogen-enriched product from the ion transport membrane assembly; and 
 an ammonia production unit operatively disposed to receive a nitrogen product from the nitrogen purification unit and operatively disposed to receive at least a portion of the hydrogen containing product from the hydrogen production unit to produce an ammonia product; 
 wherein the hydrometallurgical processing circuit is operatively disposed to receive at least a portion of the ammonia product from the ammonia production unit. 
 
     
     
         13 . The system of  claim 1  wherein the hydrometallurgical processing circuit comprises one or more of the following units:
 a drying unit operatively disposed to receive at least a portion of the metal bearing material and a drying gas containing at least a portion of the nitrogen-enriched product from the ion transport membrane assembly, the drying unit adapted to reduce a liquid content of the at least a portion of the metal bearing material by at least one of direct contact and indirect heat exchange with the drying gas to provide a dried metal bearing material for further processing in the hydrometallurgical processing circuit; and/or 
 a grinding unit operatively disposed to receive at least a portion of metal-bearing material and an oxygen-deficient grinding gas containing at least a portion of the nitrogen-enriched product from the ion transport membrane assembly, the grinding unit adapted to grind the at least a portion of the metal-bearing material in an oxygen-deficient environment by contacting the at least a portion of the metal-bearing material with the grinding gas; and/or 
 a flotation unit operatively disposed to receive a flotation slurry containing at least a portion of the metal-bearing material and an oxygen-deficient flotation gas containing at least a portion of the nitrogen-enriched product from the ion transport membrane assembly, the flotation unit adapted to pass the flotation gas through the flotation slurry to float one or more metal values of the flotation slurry with the flotation gas to provide a flotation concentrate and a flotation tail. 
 
     
     
         14 . A hydrometallurgical process for processing a metal-bearing material containing one or more metal values, the process comprising the steps of:
 (a) providing an ion transport membrane assembly comprising an ion transport membrane layer and having a feed side and a permeate side;   (b) introducing a first feed gas comprising oxygen and nitrogen into an inlet to the feed side of the ion transport membrane assembly;   (c) withdrawing a non-permeate nitrogen-enriched product from an outlet from the feed side and a permeate oxygen product from an outlet from the permeate side of the ion transport membrane assembly;   (d) providing a hydrometallurgical processing circuit comprising one or more units for carrying out the hydrometallurgical process, a process carried out in at least one of the one or more units consuming oxygen by chemical reaction, the one or more units selected from the group consisting of a grinding unit, a roasting unit, a pressure oxidation unit, a bio-oxidation unit, an upstream leaching unit, an upstream solution or slurry preparation unit, a downstream leaching unit, a further downstream leaching unit, a further downstream solution or slurry preparation unit, a lixiviant remediation unit, and an acid production unit;   (e) pre-processing the metal-bearing material in the hydrometallurgical processing circuit;   (f) leaching at least a pre-processed portion of the metal-bearing material in the hydrometallurgical processing circuit to recover at least one metal value from the metal-bearing material; and   (g) introducing an oxidant gas containing at least a portion of the oxygen product and/or activated oxygen generated from at least a portion of the oxygen product from the ion transport membrane assembly into at least one oxygen consuming unit of the one or more units of the hydrometallurgical processing circuit for oxidation.   
     
     
         15 . The process of  claim 14  further comprising:
 recycling at least a portion of an oxygen-containing effluent gas of the hydrometallurgical processing circuit in a first recycle effluent stream and/or a second recycle effluent stream; 
 and at least one of
 recycling the first recycle effluent stream to the feed side of the ion transport membrane assembly to form a portion of the first feed gas; or 
 mixing the second recycle effluent stream with at least a portion of the oxygen product of the ion transport membrane assembly to form a mixed stream containing the at least a portion of the oxygen product and the oxygen containing effluent gas of the second recycle effluent stream, and introducing the mixed stream into the at least one oxygen consuming unit of the hydrometallurgical processing circuit to provide oxidant. 
 
 
     
     
         16 . The process of  claim 14  wherein
 the hydrometallurgical processing circuit comprises a pre-processing unit and a downstream leaching unit; 
 at least a portion of the metal-bearing material is pre-processed in the pre-processing unit by one or more of grinding, roasting, pressure oxidation, bio-oxidation, upstream leaching, and/or solution or slurry preparation to produce a pre-processed material containing the at least one metal value; and 
 at least a portion of the pre-processed material is leached in step (f) in the downstream leaching unit as the at least a pre-processed portion of the metal-bearing material; 
 wherein at least a first portion of the oxidant gas is introduced into the pre-processing unit and/or at least a second portion of the oxidant gas is introduced into the downstream leaching unit for oxidation. 
 
     
     
         17 . The process of  claim 14  comprising
 operating the ion transport membrane assembly at a temperature within a membrane temperature range of 700° C. to 1000° C.; 
 withdrawing the non-permeate nitrogen-enriched product in step (c) at a temperature within the membrane temperature range; 
 withdrawing the permeate oxygen product in step (c) at a temperature within the membrane temperature range; 
 operating the at least one oxygen consuming unit at a temperature within a unit temperature range of 80° C. to 300° C.; 
 and providing oxidant to a process performed in this oxygen consuming unit by introducing at least a portion of the oxidant gas into the at least one oxygen consuming unit in step (g). 
 
     
     
         18 . The process of  claim 17 , furthermore comprising the step of recovering heat from at least a portion of the oxidant gas by heating a process stream of the hydrometallurgical processing circuit before introducing the at least a portion of the oxidant gas into the at least one oxygen consuming unit in step (g). 
     
     
         19 . The process of  claim 14  wherein at least a portion of the oxidant gas is introduced into a grinding unit for grinding at least a portion of the metal-bearing material in an oxygen containing gas or liquid; and/or wherein at least a portion of the oxidant gas is introduced into a roasting unit for roasting at least a portion of the metal-bearing material; and wherein at least a portion of the ground and/or roasted material is leached in step (f). 
     
     
         20 . The process of  claim 14  furthermore comprising at least one of the following steps:
 (i) generating steam from feed water by heat exchange with at least a portion of the nitrogen-enriched product and introducing at least a portion of the generated steam into the hydrometallurgical processing circuit; 
 (ii) heating an autoclave slurry or solution by heat exchange with at least a portion of the nitrogen-enriched product and introducing the heated autoclave slurry or solution into an autoclave of the hydrometallurgical processing circuit for leaching or pressure oxidation; 
 (iii) introducing at least a portion of the nitrogen-enriched product into an ammonia production unit to produce an ammonia product, and introducing at least a portion of the ammonia product into the hydrometallurgical processing circuit; 
 (iv) floating one or more metal values of the metal-bearing material with an oxygen-deficient flotation gas containing at least a portion of the nitrogen-enriched product in a flotation unit; 
 (v) grinding at least a portion of the metal-bearing material in a grinding unit while contacting the at least a portion of the metal-bearing material with an oxygen-deficient grinding gas containing at least a portion of the nitrogen-enriched product; or 
 (vi) drying at least a portion of the metal-bearing material by passing a drying gas containing at least a portion of the nitrogen-enriched product through the at least a portion of the metal-bearing material.