Extraction of copper and other elements from waste materials for the production of metalic copper

Abstract

A method of recovering copper from a feed material includes steps of: leaching the feed material with a lixiviant adapted to leach the copper from a feed material feed stream in a leaching circuit having a plurality of leaching vessels V 1 , V n in series, establishing a countercurrent flow in the leaching circuit, simultaneously grinding the feed material in the feed material feed stream during the leaching in at least one of the plurality of leaching vessels and recovering the copper from the lixiviant.

1 . A method of recovering copper from a feed material, comprising:
 leaching the feed material with a lixiviant adapted to leach the copper from a feed material feed stream in a leaching circuit having a plurality of leaching vessels V 1 , Vn in series;   establishing a countercurrent flow in the leaching circuit by delivering the feed material feed stream to the leaching vessel V 1  and moving the feed material feed stream through the leaching circuit in a first direction toward leaching vessel Vn and delivering the lixiviant to the leaching vessel Vn and moving the lixiviant through the leaching circuit in a second direction toward leaching vessel V 1 ; and   recovering the copper from the lixiviant.   
     
     
         2 . The method of  claim 1 , further including simultaneously grinding the feed material in the feed material feed stream during the leaching in at least one of the plurality of leaching vessels. 
     
     
         3 . The method of  claim 2 , further including using an ammonia-based lixiviant. 
     
     
         4 . The method of  claim 3 , further including using copper (II) (Cu(II)) as an oxidizer and the reagent. 
     
     
         5 . The method of  claim 4 , further including using electrowinning in the recovering of the copper metal from the lixiviant. 
     
     
         6 . The method of  claim 5 , further including conducting the leaching under anaerobic conditions to encourage generation of copper (II). 
     
     
         7 . The method of  claim 5 , further including applying a size reduction to the feed material prior to leaching. 
     
     
         8 . The method of  claim 7 , wherein the grinding is by (a) agitating the feed material feed stream and the lixiviant in the at least one leaching vessel, (b) stirring the feed material feed stream and the lixiviant in the at least one leaching vessel, (c) rotating the at least one leaching vessel in order to tumble the feed material feed stream and the lixiviant in the at least one leaching vessel or (d) all of the above (a)-(c). 
     
     
         9 . The method of  claim 8 , further including providing a grinding media, adapted for grinding the feed material, in the at least one leaching vessel. 
     
     
         10 . The method of  claim 9 , further including selecting the grinding media from a non- limiting group of materials consisting of ceramics, stones (a non-limiting example is zircon), metals, plastics, thermoset (epoxy) resins, or heterogenous (multiphase), and combinations thereof. 
     
     
         11 . The method of  claim 5 , further including completing the electrowinning using an electrowinning cell including (a) a cathode, (b) an anode, and (c) a diaphragm surrounding the cathode and defining a cathode compartment within the diaphragm. 
     
     
         12 . The method of  claim 11 , further including injecting pregnant leaching solution from the leaching circuit into the cathode compartment defined within the diaphragm. 
     
     
         13 . (canceled) 
     
     
         14 . The method of  claim 5 , further including completing the electrowinning using an electrowinning cell including (a) a cathode, (b) an anode, and (c) a diaphragm surrounding the anode and defining an anode compartment within the diaphragm. 
     
     
         15 . The method of  claim 14 , further including injecting pregnant leaching solution from the leaching circuit into a cathode compartment defined outside the diaphragm. 
     
     
         16 . (canceled) 
     
     
         17 . The method of  claim 5  including recovering residual copper from electrolyte discharged following the electrowinning. 
     
     
         18 . The method of  claim 17 , wherein the recovering of the residual ammonia includes (a) washing the electrolyte with ammonia in countercurrent fashion while preventing copper precipitation, (b) recovering the ammonia and captured copper from remaining liquid and (c) heating the remaining liquid to evaporate and recover residual ammonia. 
     
     
         19 . The method of  claim 5 , further including treating vapor phase fluids generated during the method in an ammonia and water recovery circuit including a condenser, an absorber, an evaporator and a boiler. 
     
     
         20 . The method of  claim 19 , including (a) condensing ammonia vapor in the condenser, (b) contacting fluids discharged from the condenser with cooling water in the absorber whereby ammonia is absorbed in the water and treated gas is discharged to atmosphere, (c) heating outflow from the absorber in the evaporator to drive off remaining ammonia that is returned to the condenser and discharging underflow of ammonia-free water to the boiler, (d) boiling the ammonia-free water received from the evaporator and using that steam to heat other streams used during the method, (e) leaching base metals other than copper from the feed material and recovering the other base metals from the lixiviant, and (f) completing the electrowinning using an anode made from a first material selected from a first group consisting of stainless steel, 316 stainless steel, 316L stainless steel, titanium, platinized titanium, titanium coated with mixed metal oxide, graphite and combinations thereof and using a cathode made from a second material selected from a second group of materials consisting of stainless steel, 316 stainless steel, 316L stainless steel, titanium, platinized titanium and combinations thereof. 
     
     
         21 . (canceled) 
     
     
         22 . (canceled) 
     
     
         23 . (canceled) 
     
     
         24 . (canceled) 
     
     
         25 . (canceled) 
     
     
         26 . The method of  claim 5 , including (a) maintaining the lixiviant at a pH of between about 5 and 13.5, (b) maintaining the current density during the electrowinning between about 50 and about 1500 A/m 2  to induce plating of the copper rather than the generation of copper (I) and (c) maintaining an Eh between about 0.0 and about −400 mv versus Ag/AgCL reference electrode to maintain Cu(II) as dominant Cu ion in the lixiviant. 
     
     
         27 . The method of  claim 5 , including (a) maintaining the lixiviant at a pH of between about 10 and 13.5, (b) maintaining the current density during the electrowinning between about 50 and about 1500 A/m 2  to induce plating of the copper rather than the generation of copper (I) and (c) maintaining an Eh between about 0.0 and about −400 mv versus Ag/AgCL reference electrode to maintain Cu(II) as dominant Cu ion in the lixiviant.