Use of a rare earth for the removal of antimony and bismuth

Abstract

The invention relates generally to a process for removing one or more contaminants from an electrolytic solution and more particularly to a process for removing the one or more contaminants contained in an electrorefining solution using rare earth metals.

1 . A process, comprising:
 (a) forming, by an electrolytic cell, an electrolytic stream comprising a target material and a valuable metal, wherein the electrolytic stream has a first target material concentration;   (b) contacting the electrolytic stream with an insoluble fixing agent to form a target material-loaded insoluble fixing agent and a purified electrolytic stream, the insoluble fixing agent comprising at least one of yttrium, scandium, and a lanthanoid, the target material-loaded insoluble fixing comprising most of the target material in the electrolyte stream, wherein the target material, in the target material-loaded insoluble fixing agent, forms a composition with the insoluble fixing agent; and   (c) cycling the purified electrolytic stream to the electrolytic cell, wherein the purified stream has a second target material concentration substantially less than the first target material concentration.   
     
     
         2 . The process of  claim 1 , wherein the electrolytic stream is a side stream. 
     
     
         3 . The process of  claim 1 , wherein step (b) further comprises contacting at least a portion of the stream with the insoluble fixing agent. 
     
     
         4 . The process of  claim 1 , wherein, in the contacting step (b), substantially little, if any, of the valuable metal is removed from the electrolytic stream. 
     
     
         5 . The process of  claim 1 , wherein the target material comprises at least one of arsenic, antimony, bismuth, tin, lead, selenium, tellurium, platinum, iridium, ruthenium, and rhodium. 
     
     
         6 . The process of  claim 1 , wherein the target material comprises an oxyanion. 
     
     
         7 . The process of  claim 6 , wherein the oxyanion comprises at least one of tellurium, selenium, bismuth, antimony and arsenic. 
     
     
         8 . The process of  claim 1 , wherein the valuable metal comprises copper. 
     
     
         9 . The process of  claim 1 , wherein the insoluble fixing agent comprises cerium. 
     
     
         10 . The process of  claim 9 , wherein the cerium comprises cerium oxide. 
     
     
         11 . The process of  claim 1 , wherein the insoluble fixing agent comprises a finely divided solid having a surface area from about 25 m 2 /g to about 500 m 2 /g. 
     
     
         12 . The process of  claim 1 , further comprising:
 (d) contacting the target material-loaded insoluble fixing agent with a stripping solution to dissolve, solublize, or otherwise displace most of the target material in the target material-loaded insoluble fixing agent to form a loaded stripping solution and barren insoluble fixing agent.   
     
     
         13 . The process of  claim 12 , wherein the stripping solution comprises at least one of a strong base, an oxalate, ethanedioate, a strongly absorbing exchange oxyanion, a reductant or reducing agent, and oxidant or oxidizing agent. 
     
     
         14 . The process of  claim 12 , further comprising:
 (e) cycling the barren insoluble fixing agent to contacting step (b), wherein the barren insoluble fixing agent is contacted with the electrolytic stream to form target material-loaded insoluble fixing agent.   
     
     
         15 . The process of  claim 12 , further comprising:
 (f) removing at least most of the dissolved target material from the loaded stripping solution.   
     
     
         16 . A process, comprising:
 (a) forming, by an electrolytic cell, an electrolytic stream comprising a target material and a valuable metal, wherein the electrolytic stream has a first target material concentration;   (b) contacting the electrolytic stream with a fixing agent to form an insoluble composition;   (c) removing the insoluble composition from the electrolytic stream to form a purified electrolyte stream; and   (d) cycling the purified electrolytic stream to the electrolytic cell, wherein the purified stream has a second target material concentration substantially less than the first target material concentration.   
     
     
         17 . The process of  claim 16 , wherein the electrolytic stream is a side stream. 
     
     
         18 . The process of  claim 16 , wherein step (b) further comprises contacting at least a portion of the stream with the fixing agent. 
     
     
         19 . The process of  claim 16 , wherein the fixing agent comprises a non-rare earth salt additive, the non-rare earth salt additive comprises a non-rare earth metal having a +3 oxidation and being substantially free of a rare earth and wherein the insoluble composition comprises a precipitate formed between the target material and the non-rare earth salt additive. 
     
     
         20 . The process of  claim 19 , wherein the non-rare earth salt additive comprises one of boron, aluminum, gallium, indium, thallium and a transition metal. 
     
     
         21 . The process of  claim 16 , wherein the rare earth-containing fixing agent comprises a rare earth salt additive, the rare earth salt additive comprises a rare earth having a +3 oxidation state and a non-rare metal having a +3 oxidation state and wherein the insoluble composition comprises a precipitate formed between the target material and at least one of the rare earth and the non-rare earth. 
     
     
         22 . The process of  claim 21 , wherein the non-rare earth is one of boron, aluminum, gallium, indium, thallium and a transition metal. 
     
     
         23 . The process of  claim 16 , wherein the fixing agent comprises a rare earth, the rare earth is a soluble rare earth, and wherein the insoluble composition comprises an insoluble target material-containing composition comprising the target material and the rare earth. 
     
     
         24 . The process of  claim 16 , wherein the electrolytic stream contains a valuable metal and wherein at least most, if not all, of the valuable metal within the electrolytic stream is cycled to the electrolytic cell by the purified electrolytic stream. 
     
     
         25 . The process of  claim 16 , wherein the electrolytic stream contains copper, wherein at least most, if not all, of the copper within the electrolytic stream is cycled to the electrolytic cell by the purified electrolytic stream and wherein the target material comprises one or more of arsenic, antimony, bismuth, tin, lead, selenium, tellurium, platinum, iridium, ruthenium, and rhodium. 
     
     
         26 . A process, comprising:
 (a) forming, by an electrolytic cell, an electrolytic stream comprising a target material and dissolved copper, wherein the electrolytic stream has a first target material concentration;   (b) contacting the electrolytic stream with an insoluble rare earth-containing fixing agent to form a target material-loaded insoluble fixing agent and a purified electrolytic stream having at least most, if not all, of the copper contained with the electrolytic stream, the rare earth-containing insoluble fixing agent comprising at least one of yttrium, scandium, and a lanthanoid, the target material-loaded insoluble fixing comprising most of the target material in the electrolyte stream, wherein the target material, in the target material-loaded insoluble fixing agent, forms a composition with the insoluble fixing agent; and   (c) cycling the purified electrolytic stream to the electrolytic cell, wherein the purified stream has a second target material concentration substantially less than the first target material concentration.   
     
     
         27 . The process of  claim 26 , wherein the electrolytic stream is a side stream. 
     
     
         28 . The process of  claim 26 , wherein step (b) further comprises contacting at least a portion of the electrolytic stream with the insoluble rare earth-containing fixing agent. 
     
     
         29 . The process of  claim 26 , wherein substantially little, if any, of the dissolved copper is removed from the electrolytic stream in the contacting step (b), and wherein the target material comprises at least one of arsenic, antimony, bismuth, tin, lead, selenium, tellurium, platinum, iridium, ruthenium, and rhodium. 
     
     
         30 . The process of  claim 26 , wherein the target material comprises an oxyanion of at least one of tellurium, selenium, bismuth, antimony and arsenic. 
     
     
         31 . The process of  claim 26 , wherein the rare earth-containing fixing agent comprises cerium oxide. 
     
     
         32 . The process of  claim 26 , wherein the insoluble fixing agent comprises a finely divided solid having a surface area from about 25 m 2 /g to about 500 m 2 /g. 
     
     
         33 . The process of  claim 26 , further comprising:
 (d) contacting the target material-loaded insoluble fixing agent with a stripping solution to dissolve, solublize, or otherwise displace most of the target material in the target material-loaded insoluble fixing agent to form a loaded stripping solution and barren insoluble fixing agent, wherein the stripping solution comprises at least one of a strong base, an oxalate, ethanedioate, a strongly absorbing exchange oxyanion, a reductant or reducing agent, and oxidant or oxidizing agent;   (e) cycling the barren insoluble fixing agent to contacting step (b), wherein the barren insoluble fixing agent is contacted with the electrolytic stream to form target material-loaded insoluble fixing agent; and   (f) removing at least most of the dissolved target material from the loaded stripping solution.   
     
     
         34 . A process, comprising:
 (a) receiving a rich feed solution having a target material and a valuable metal;   (b) electrodepositing the valuable metal onto an electrode to form an electrolyzed solution, wherein at least most of the valuable metal is electrodeposited onto the electrode; and   (c) contacting at least a portion of at least one of the rich feed solution and the electrolyzed solution with a rare earth-containing fixing agent to form a target material-loaded insoluble fixing agent, the target material-loaded insoluble fixing agent comprising at least most of the target material in the at least a portion of the at least one of the rich feed solution and the barren solution, wherein the target material, in the target material-loaded insoluble fixing agent, forms a composition with the fixing agent and the target material is at least one of antimony and bismuth.   
     
     
         35 . The process of  claim 34 , further comprising:
 (d) separating the target material-laded insoluble fixing agent from at least one of the rich feed stream and the electrolyzed solution to form a purified stream and a solid target material-laded insoluble fixing agent.   
     
     
         36 . The process of  claim 35 , further comprising at least one of:
 (e) recover target material; and   (f) recycle purified stream to electrolysis cell.   
     
     
         37 . The process of  claim 34 , wherein substantially little, if any, of the valuable metal is removed from one or both of the rich feed stream and the electrolyzed solution in the contacting step (c). 
     
     
         38 . The process of  claim 34 , wherein the target material comprises an oxyanion. 
     
     
         39 . The process of  claim 34 , wherein the electrodepositing is one an electrowinning or electrorefining of the valuable metal. 
     
     
         40 . The process of  claim 38 , wherein the valuable metal comprises a metal having an atomic number of 22-30, 40-48, and 72-79. 
     
     
         41 . The process of  claim 34 , wherein the insoluble fixing agent comprises cerium. 
     
     
         42 . The process of  claim 41 , wherein the cerium comprises cerium oxide. 
     
     
         43 . The process of  claim 34 , wherein the insoluble fixing agent comprises a finely divided solid having a surface area from about 25 m 2 /g to about 500 m 2 /g. 
     
     
         44 . The process of  claim 34 , further comprising:
 (g) contacting the target material-loaded insoluble fixing agent with a stripping solution to dissolve, solublize, or otherwise displace most of the target material in the target material-loaded insoluble fixing agent to form a loaded stripping solution and barren insoluble fixing agent, wherein the stripping solution comprises at least one of a strong base, an oxalate, ethanedioate, a strongly absorbing exchange oxyanion, a reductant or reducing agent, and an oxidant or oxidizing agent; and   (h) cycling the barren insoluble fixing agent to contacting step (c), wherein the barren insoluble fixing agent is contacted with one of the rich feed stream and the electrolyzed solution to form the target material-loaded insoluble fixing agent.   
     
     
         45 . The process of  claim 44 , further comprising:
 (f) removing at least most of the dissolved target material from the loaded stripping solution.