Method for recovering rhenium and other metals from rhenium-bearing materials

Abstract

A method of recovering rhenium (Re) and other metals from Re-bearing materials in the form of ammonium perrhenate having at least the step of adding Re-bearing materials into a leaching slurry. Additionally, the method has the step of adjusting the pH of the slurry to obtain Re in soluble form in a metal salt solution and insoluble residues; filtering the metal salt solution to remove the insoluble residues; selectively precipitating Re from the metal salt solution; and filtering the Re precipitate from the metal salt solution to obtain a Re filtercake. The method further has the step of drying and formulating Re to produce Re sulfide product.

What is claimed is: 
     
         1 . A method of selectively recovering rhenium in the form of Re sulfide from a Re-bearing material, comprising the steps of:
 (i) adding Re-bearing materials into a leaching slurry;   (ii) adjusting the pH of the leaching slurry to obtain Re in soluble form in a metal salt solution;   (iii) filtering the metal salt solution to remove insoluble fractions;   (iv) selectively precipitating Re from the metal salt solution; and   (v) filtering the Re precipitate from the metal salt solution to obtain a Re filtercake, and (vi) drying and formulating Re to produce Re sulfide.   
     
     
         2 . The method according to  claim 1 , wherein the Re-bearing material is a super alloy waste, sludge, byproduct, or residue resulting from the manufacturing and/or subsequent repair of high-temperature industrial turbines, turbine components, superconductor components, vacuum plasma metal deposition processes, and bimetallic reforming catalyst materials. 
     
     
         3 . The method according to  claim 1 , wherein the pH of the leaching slurry in step (ii) is adjusted by adding an acid in an amount sufficient to solubilize metals as metal salts. 
     
     
         4 . The method according to  claim 3 , where the acid in step (ii) is aqua regia. 
     
     
         5 . The method according to  claim 1 , where an oxidant is added in step (iv) in an amount sufficient to oxidize Re to the heptavalent state. 
     
     
         6 . The method according to  claim 1 , where a precipitant is added in step (iv) in an amount sufficient to precipitate the Re and obtain Re 2 S 7 . 
     
     
         7 . The method according to  claim 6 , where the precipitant is NaHS. 
     
     
         8 . The method according to  claim 1 , where a solution of metal salts is separated from the Re filtercake in step (v) and the solution of metal salts contain at least one metal selected from the group consisting of Ni, Co, Cr, Hf, Ti, Ta, W, Mo and a platinum group metal. 
     
     
         9 . The method according to  claim 8 , where the pH of the solution of metal salts is increased to precipitate metal hydroxides containing at least one metal selected from the group consisting of Ni, Co, Cr, Hf, Ti, Ta, W, Mo and a platinum group metal. 
     
     
         10 . The method according to  claim 9 , further comprising filtering the solution and precipitate to obtain a filtercake that contains at least one metal selected from the group consisting of Ni, Co, Cr, Hf, Ti, Ta, W, Mo and a platinum group metal. 
     
     
         11 . The method according to  claim 1 , where the insoluble fractions from step (iii) contain at least one metal selected from the group consisting of Ni, Co, Cr, Hf, Ti, Ta, W, Mo and a platinum group metal. 
     
     
         12 . The method according to  claim 11 , where the insoluble fractions are formulated or compounded to obtain a metal concentrate. 
     
     
         13 . The method according to  claim 1 , where the Re-bearing material is a super alloy waste, sludge, byproduct, or residue resulting from the manufacturing and/or subsequent repair of high-temperature industrial turbines, turbine components, superconductor components, vacuum plasma metal deposition processes, and bimetallic reforming catalyst materials. 
     
     
         14 . The method according to  claim 1  for producing ammonium perrhenate, further comprising the steps of:
 roasting the Re sulfide product to oxidize the rhenium sulfide to rhenium heptoxide, wherein said rhenium heptoxide sublimes into flue gas and a metal oxide; and 
 treating the flue gas to obtain ammonium perrhenate. 
 
     
     
         15 . The method according to  claim 1  for producing metal concentrate further comprising the step of formulating or compounding the insoluble fractions to obtain said metal concentrate. 
     
     
         16 . The method according to  claim 1  for producing molybdenum oxide further comprising the step of combining the Re sulfide with molybdenum concentrate containing Re to obtain a Mo/Re concentrate and treating the Mo/Re concentrate to recover the molybdenum oxide. 
     
     
         17 . The method according to  claim 1  for producing copper concentrate further comprising the steps of combining the Re sulfide with molybdenum concentrate containing Re to obtain a Mo/Re concentrate, wherein the molybdenum concentrate containing Re is obtained by treating copper ore containing Mo and Re with a porphyry Cu ore flotation process to obtain Mo/Cu/Re/concentrate, and treating the Mo/Cu/Re concentration with a flotation process to obtain copper concentrate.