Process for producing refined metal or metalloid

Abstract

Process for producing a refined metal or metalloid, comprising: an electrolysis step of, in an electrolytic bath set in a container for an electrolysis in which a material comprising a metal element or metalloid element and impurities acts as an anode, and an alloy comprising the same metal element or metalloid element as the metal element or metalloid element and a medium metal that does not substantially form a solid solution with the metal element or metalloid element and having a complete solidification temperature lower than the melting point of the metal element or metalloid element acts as a cathode, performing electrolysis at a temperature at which the alloy can be a liquid phase; withdrawing a part or the whole of the alloy of the cathode to an outside of the container; cooling the withdrawn alloy at a temperature higher than the complete solidification temperature and lower than the electrolysis temperature; and a recovery step.

1 . A process for producing a refined metal or metalloid, comprising:
 an electrolysis step of, in an electrolytic bath provided within an electrolyzer where a material comprising a metal element or metalloid element and impurities is subjected to act as an anode, and an alloy comprising the same metal element or metalloid element as the metal element or metalloid element contained in the anode and a solvent metal that does not substantially form a solid solution with the metal element or metalloid element and having a complete solidification temperature lower than a melting point of the metal element or metalloid element is subjected to act as a cathode, performing electrolysis at an electrolysis temperature allowing the alloy to be a liquid phase to move the metal element or metalloid element in the anode into the alloy of the cathode;   an withdrawal step of withdrawing part or a whole of the alloy of the cathode to an outside of the electrolyzer after the electrolysis step;   a deposition step of cooling the withdrawn alloy at a temperature higher than the complete solidification temperature and lower than the electrolysis temperature to deposit the metal element or metalloid element contained in the alloy; and   a recovery step of recovering the metal element or metalloid element deposited from the cooled alloy.   
     
     
         2 . The process according to  claim 1 , wherein the solvent metal has a eutectic point with the metal element or metalloid element. 
     
     
         3 . The process according to  claim 1 , further comprising a reuse step of using a residue after the metal element or metalloid element deposited is recovered from the cooled alloy, as the cathode in the electrolysis step. 
     
     
         4 . The process according  claim 1 , wherein the metal element or metalloid element is silicon or germanium. 
     
     
         5 . The process according to  claim 4 , wherein the alloy of the cathode comprises one or more metal elements selected from the group consisting of aluminum, silver, copper, and zinc. 
     
     
         6 . The process according to  claim 4 , wherein the material for the anode comprises one or more metal elements selected from the group consisting of silver, copper, tin, and lead. 
     
     
         7 . The process according to  claim 1 , wherein the electrolytic bath comprises cryolite. 
     
     
         8 . The process according to  claim 1 , wherein the electrolysis temperature is higher than the complete solidification temperature and lower than the melting point of the metal element or metalloid element.