Platinum group metal refining

Abstract

A process for refining platinum group metals (PGM) first removes concentrations of base metals (BM) from the PGM through precipitation of the BM by increasing alkalinity in the dissolving aqueous solution. A large fraction of the aqueous solution is distilled before increasing alkalinity. Os is recovered from the distillate The aqueous solution is heated following precipitation of the BM; and the PGM is loaded on borane containing reduction resins. The loaded resins are washed; and the PGM is stripped from the resins with gaseous oxygen. The stripped PGM are then processed using only substituted quaternary ammonium salt (SQAS) as the refining reagent. The waste solutions from the refining are all combined together; solvent is removed; residual PGM is recycled in the process; and concentrated SQAS is recovered for further refining. Pt, Pd and Ru are refined from acidic SQAS solutions by reducing the metals from the solutions with H 2 .

1 . Removing concentrations of base metals (BM) from platinum group metals (PGM) comprising
 dissolving any of BM and PGM in an acidic aqueous solution;   precipitating the BM by increasing alkalinity in the aqueous solution;   loading the PGM on borane containing reduction resin from the aqueous solution as metal;   stripping the PGM from the resins using oxidizing agents.   
     
     
         2 . The process of  claim 1  further comprising
 distilling a large fraction of the aqueous solution before increasing alkalinity in the aqueous solution. 
 
     
     
         3 . The process of  claim 2  further comprising
 recovering Os from the distillate. 
 
     
     
         4 . The process of  3   claim 1 , loading the PGM on resin being in an inert atmosphere. 
     
     
         5 . The process of  claim 1 , stripping the PGM from the borane resin through oxidation being with gaseous oxygen. 
     
     
         6 . Removing concentrations of base metals (BM) from platinum group metals (PGM) comprising
 dissolving any of BM and PGM in an acidic aqueous solution;   distilling a large fraction of the aqueous solution before increasing alkalinity in the aqueous solution;   precipitating the BM by increasing alkalinity in the aqueous solution;   heating the aqueous solution following precipitation of the BM;   loading the PGM on borane containing reduction resins from the heated aqueous solution;   washing the loaded resins;   stripping the PGM from the resins with gaseous oxygen.   
     
     
         7 . The process of  claim 6  further comprising
 recovering Os from the distillate. 
 
     
     
         8 . The process of  claim 6 , loading PGM on resin being in an inert atmosphere. 
     
     
         9 . Refining at least one platinum group metal (PGM) from substituted quaternary ammonium salt (SQAS) bonded metal, comprising
 preparing a neutral to acidic PGM-SQAS solution;   reducing the PGM from the solution with H 2 .   
     
     
         10 . The process of  claim 9 , preparing the neutral to acidic PGM-SQAS solution including refluxing PGM with SQAS and HCl, oxidizing the refluxed solution with halogen to obtain a PGM-SQAS precipitate, refluxing the PGM-SQAS precipitate in boiling water to the neutral to acidic PGM-SQAS solution. 
     
     
         11 . The process of  claim 9 , the neutral to acidic PGM-SQAS solution being a slurry. 
     
     
         12 . The process of  claim 9 , the PGM being one of Pd, Pt or Rh. 
     
     
         13 . The process of  claim 9  further comprising separating the PGM-SQAS by individual elements of PGM-SQAS before reducing the PGM from the solution with H 2 . 
     
     
         14 . A process fro refining PGM comprising
 refining PGM using SQAS as the refining reagent in solution;   separating each refined PGM from the refining reagent solution;   combining all refining reagent solutions together;   precipitating residual PGM;   recycling the precipitated residual PGM to the refining of PGM;   recycling the concentrated SQAS as the refining reagent in solution.   
     
     
         15 . The process of  claim 13 , precipitating residual PGM including removing solvent from the combined refining reagent in solution.