Recovery of rhenium from a spent catalyst via sublimation

Abstract

This invention provides a method for recovering rhenium oxide from a material containing rhenium by itself or rhenium in combination with some other element, such as an element catalytically active for a catalytic process, such as hydrogenation, oxidation, reforming, and hydrocracking. The method includes conversion of rhenium to a sublimable oxide via oxidation, heating in an oxidizing atmosphere to sublime the oxide as a volatized oxide, and then isolation of rhenium from the volatized oxide.

What is claimed is:  
     
         1 . A method for recovering rhenium from a spent catalyst comprising rhenium, the method comprising: 
 heating the spent catalyst in an oxidizing atmosphere at a temperature effective to sublime a portion of the rhenium as a volatized oxide.    
     
     
         2 . The method according to  claim 1  wherein the atmosphere is at standard pressure and the temperature is between about 250° C. and about 400° C.  
     
     
         3 . The method according to  claim 1  further comprising: 
 scrubbing the volatized oxide with an aqueous medium to form a rhenium-bearing aqueous solution.  
 
     
     
         4 . The method according to  claim 3  further comprising: 
 separating rhenium from the aqueous solution so as to form a rhenium-bearing solid.  
 
     
     
         5 . The method according to  claim 1  wherein the portion comprises at least 25% of the rhenium.  
     
     
         6 . The method according to  claim 1  wherein the spent catalyst further comprises a second metal.  
     
     
         7 . A method for recovering rhenium and a second metal from a spent catalyst comprising rhenium and the second metal, the method comprising: 
 (a) heating the spent catalyst in an oxidizing atmosphere at a temperature effective to sublime a portion of the rhenium as a volatized oxide and to form a catalyst remainder; and    (b) removing at least a portion of the second metal from the catalyst remainder.    
     
     
         8 . The method according to  claim 7  wherein the atmosphere is at standard pressure and the temperature is between about 250° C. and about 400° C.  
     
     
         9 . The method according to  claim 7  further comprising: 
 (c) scrubbing the volatized oxide with an aqueous medium to form an aqueous rhenium-bearing solution.  
 
     
     
         10 . The method according to  claim 9  further comprising: 
 (d) separating rhenium from the aqueous solution so as to form a rhenium-bearing solid.  
 
     
     
         11 . The method according to  claim 7  wherein the portion of the rhenium comprises at least 25% of the rhenium.  
     
     
         12 . The method according to  claim 7  wherein step (b) comprises: 
 (b1) dissolving the catalyst remainder in an acid solution; and  
 (b2) extracting the second metal from the acid solution.  
 
     
     
         13 . The method according to  claim 12  wherein the portion of the second metal comprises at least 50% of the second metal.  
     
     
         14 . The method according to  claim 7  wherein the second metal is a metal catalytically active for a catalytic process selected from among hydrogenation, oxidation, reforming, and hydrocracking.  
     
     
         15 . A method for reclaiming rhenium from a spent catalyst, comprising: 
 (a) heating the spent catalyst in an oxidizing atmosphere at a temperature effective to sublime a portion of rhenium as a volatilized oxide;    (b) isolating the rhenium from the volatized oxide; and    (c) incorporating the isolated metal in a fresh catalyst.    
     
     
         16 . The method according to  claim 15  wherein the atmosphere is at standard pressure and the temperature is between about 250° C. and about 400° C.  
     
     
         17 . The method according to  claim 15  further comprising: 
 (d) scrubbing the volatized oxide with an aqueous medium to form a rhenium-bearing aqueous solution.  
 
     
     
         18 . The method according to  claim 17  further comprising: 
 (e) separating rhenium from the aqueous solution so as to form a rhenium-bearing solid.  
 
     
     
         19 . The method according to  claim 15  wherein the portion of rhenium comprises at least 25% of the rhenium.  
     
     
         20 . The method according to  claim 15  wherein step (c) comprises loading a catalyst support with the reclaimed rhenium.