Process for recovering platinum group metals, rhenium and gold

Abstract

Processing for the extraction of metals consisting of platinum, palladium, iridium, rhodium, osmium, ruthenium, rhenium and gold (PGMRA) includes dissolution of the PGMRA metals from solid materials in an acidic aqueous solution, preferably with a halogen acid sparged with the corresponding halogen element. The acidic solution is then exposed to extraction material of non-cross-linked polyamine composite resin. The bound metal, following washing of the extraction material is eluted from the resin using stronger acidic processes than that provided in the wash of the resin. Conventional extraction by organic solvents or other known techniques is employed to recover the PGMRA metals. Rhodium is separated from the rest of the PGMRA metals either near the beginning or the end of the process. Rhodium is separated by creating hydroxides with the metals in the solution and then reacidifying the metals such that the rhodium remains as aquochlororhodate complexes. Using the binding process to the extraction material leaves only the aquochlororhodate complexes in solution to be recovered. All of the PGMRA metals may be recovered by conventional means such as organic solvents, reduction or precipitation.

1 . A method for the extraction of metals from source materials, comprising
 binding more than one dissolved PGMRA metal selected from the group consisting of Pt, Pd, Ir, Rh, Os, Ru, Re and Au in an acidic aqueous solution to extraction material of non-cross linked polyamine composite resin on a substrate including exposing the dissolved PGMRA metals to the extraction material;   washing the non-cross linked polyamine composite resin and the bound PGMRA metals with dilute acid;   eluting the bound PGMRA metals from the extraction material with at least one eluting acid including sequentially eluting with eluting acid of increasing specific stripping capacity to separately elute individual ones of the bound PGMRA metals.   
   
   
       2 . The method of  claim 1 , binding the more than one dissolved PGMRA metal being at temperatures, pressures and acid normality below that which elutes the bound PGMRA metals from the extraction material. 
   
   
       3 . The method of  claim 1 , binding the more than one dissolved PGMRA metal being in an acidic solution of 0.01-0.0001 N hydrochloric acid. 
   
   
       4 . The method of  claim 3 , binding the more than one dissolved PGMRA metal further including limiting the extraction material to an amount having a capacity to bind no more than the PGMRA metals available in solution. 
   
   
       5 . The method of  claim 1 , binding the more than one dissolved PGMRA metal further including limiting the extraction material to an amount having a capacity to bind no more than the PGMRA metals available in solution. 
   
   
       6 . The method of  claim 1 , binding the more than one dissolved PGMRA metal being in perchloric, nitric or sulfuric acid solution. 
   
   
       7 . The method of  claim 6 , washing the non-cross linked polyamine composite resin and the bound PGMRA metals being with a hydrochloric, hydrobromic or hydroiodic wash solution. 
   
   
       8 . The method of  claim 7 , washing the non-cross linked polyamine composite resin and the bound PGMRA metals being at temperatures, pressures and acid normality below that which elutes the bound PGMRA metals from the extraction material. 
   
   
       9 . The method of  claim 1 , washing the non-cross linked polyamine composite resin and the bound PGMRA metals being with a hydrochloric, hydrobromic or hydroiodic wash solution. 
   
   
       10 . The method of  claim 9 , washing the non-cross linked polyamine composite resin and the bound PGMRA metals being at temperatures, pressures and acid normality below that which elutes the bound PGMRA metals from the extraction material. 
   
   
       11 . The method of  claim 1 , eluting the bound PGMRA metals from the extraction material being with hydrochloric, hydrobromic or hydroiodic acid. 
   
   
       12 . The method of  claim 1 , the increasing specific stripping capacity resulting from one or more of increasingly acidic solubility, increasing acid concentration, increasing pressure or increasing temperature. 
   
   
       13 . The method of  claim 12 , eluting further including soxhlet extraction. 
   
   
       14 . The method of  claim 12  further comprising
 extracting at least one of the eluted PGMRA metals from the eluting acid with one of an organic solvent, a reducing agent or a precipitating agent.   
   
   
       15 . The method of  claim 1 , the non-cross linked polyamine composite resin including functional chelating groups. 
   
   
       16 . A method for the extraction of metals from source materials, comprising
 binding more than one dissolved PGMRA metal selected from the group consisting of Pt, Pd, Ir, Rh, Os, Ru, Re and Au with one of the selected dissolved PGMRA metals being either Pt or Au in an acidic aqueous solution to extraction material of non-cross linked polyamine composite resin on a substrate including exposing the dissolved PGMRA metals to the extraction material;   washing the non-cross linked polyamine composite resin and the bound PGMRA metals with dilute acid;   eluting the bound PGMRA metals from the extraction material with at least one eluting acid including sequentially eluting with eluting acid of increasing specific stripping capacity to separately elute individual ones of the bound PGM RA metals.   
   
   
       17 . The method of  claim 16 , binding the more than one dissolved PGMRA metal being in an acidic solution of 0.01-0.0001 N hydrochloric acid. 
   
   
       18 . The method of  claim 16 , washing the non-cross linked polyamine composite resin and the bound PGMRA metals being with a hydrochloric, hydrobromic or hydroiodic wash solution. 
   
   
       19 . The method of  claim 18 , washing the non-cross linked polyamine composite resin and the bound PGMRA metals being at temperatures, pressures and acid normality below that which elutes the bound PGMRA metals from the extraction material. 
   
   
       20 . The method of  claim 16 , eluting the bound PGMRA metals from the extraction material being with hydrochloric, hydrobromic or hydroiodic acid. 
   
   
       21 . The method of  claim 16 , the increasing specific stripping capacity resulting from one or more of increasingly acidic solubility, increasing acid concentration, increasing pressure or increasing temperature.