Method for platinum recovery from materials containing rhenium and platinum metals

Abstract

The present disclosure relates to hydrometallurgical methods for the isolation and recovery of platinum from rhenium-containing materials, and more particularly, from superalloys containing rhenium, platinum, and other metals. The disclosure also relates to apparatuses capable of carrying out the hydrometallurgical methods and the product streams generated from the methods and apparatuses.

We claim: 
     
         1 . A system configured to separate platinum and rhenium wherein the system comprises:
 an apparatus configured to digest an alloy feed comprising platinum and rhenium in a complexing ligand comprising halides in an amount sufficient to complex the platinum present in the alloy feed;   an apparatus configured to separate resulting solids from the liquid comprising platinum and rhenium, wherein a concentration of rhenium and/or platinum in the resulting solids is from 50 to 100% lower than a concentration of rhenium and/or platinum in the alloy feed;   an apparatus configured to contact a liquid comprising platinum and rhenium with a chelating ion exchange resin, whereby the platinum is adsorbed onto the chelating ion exchange resin,   an apparatus configured to obtain a liquid stream comprising a higher relative concentration of rhenium to platinum than a relative concentration of rhenium to platinum in the liquid comprising platinum and rhenium.   
     
     
         2 . The system of  claim 1 , wherein the chelating ion exchange resin is functionalized with thiourea or thiouronium groups. 
     
     
         3 . The system of  claim 1 , wherein the pH of the liquid comprising platinum and rhenium is below 5. 
     
     
         4 . The system of  claim 1 , wherein the complexing ligand is selected from the group consisting of hydrochloric acid, a chloride containing salt, bromine and bromide salts, or chlorine. 
     
     
         5 . The system of  claim 1 , wherein the apparatus configured to digest an alloy feed is configured to digest the alloy feed comprising platinum and rhenium in an oxidant capable of oxidizing both platinum and rhenium from their metallic zero-valence state to platinum's fourth oxidation state and rhenium's heptavalent oxidation state. 
     
     
         6 . The system of  claim 5 , wherein the oxidant is selected from the group consisting of peroxides, nitric acid and its salts, chlorates, chlorine, HCl, sulfuric acid, sodium chlorite, acids, oxygen, air, and mixtures thereof. 
     
     
         7 . The system of  claim 6 , wherein the oxidant is chlorate or a mixture of HCl and sulfuric acid. 
     
     
         8 . The system of  claim 6 , wherein the oxidant is sodium chlorite and an acid. 
     
     
         9 . The system of  claim 1 , wherein the apparatus configured to obtain a liquid stream comprising a higher relative concentration of rhenium to platinum than a relative concentration of rhenium to platinum in the liquid comprising platinum and rhenium is configured to obtain a concentration of rhenium and/or platinum in the resulting solids that is from 90 to 100% lower than a concentration of rhenium and/or platinum in the alloy feed. 
     
     
         10 . The system of  claim 1 , further comprising an apparatus configured to decrease an oxidative reduction potential value of the liquid comprising platinum and rhenium. 
     
     
         11 . The system of  claim 10 , wherein the apparatus configured to decrease an oxidative reduction potential value of the liquid comprising platinum and rhenium is configured to add reducing agents to the liquid comprising platinum and rhenium. 
     
     
         12 . The system of  claim 11 , wherein the reducing agents are capable of reducing platinum (IV) to platinum (II) without affecting the oxidation state of rhenium in solution (Re(VII)). 
     
     
         13 . The system of  claim 12 , wherein the reducing agents comprise sulfites, sulfur dioxide gas, or N 2 H 4  salts. 
     
     
         14 . The system of  claim 12 , wherein the reducing agents comprise anhydrous sulfur dioxide, or a salt thereof, ascorbic acid, ethanol, or hydroxylamine hydrochloride. 
     
     
         15 . The system of  claim 10 , wherein the apparatus configured to decrease an oxidative reduction potential value of the liquid comprising platinum and rhenium is configured to treat the liquid comprising platinum and rhenium with sulfur dioxide gas. 
     
     
         16 . The system of  claim 1 , wherein the apparatus configured to digest an alloy feed is configured to adsorb onto the chelating ion exchange resin at least 60% of the platinum present in the liquid comprising platinum and rhenium. 
     
     
         17 . The system of  claim 16 , wherein the apparatus configured to digest an alloy feed is configured to adsorb onto the chelating ion exchange resin at least 90% of the platinum present in the liquid comprising platinum and rhenium. 
     
     
         18 . The system of  claim 17 , wherein the apparatus configured to digest an alloy feed is configured to adsorb onto the chelating ion exchange resin at least 99% of the platinum present in the liquid comprising platinum and rhenium. 
     
     
         19 . The system of  claim 1 , wherein the apparatus configured to digest an alloy feed is configured to adsorb onto the chelating ion exchange resin less than 10% by weight of rhenium, relative to the amount of platinum adsorbed onto the chelating ion exchange resin. 
     
     
         20 . The system of  claim 19 , wherein the apparatus configured to digest an alloy feed is configured to adsorb onto the chelating ion exchange resin less than 1% by weight of rhenium, relative to the amount of platinum adsorbed onto the chelating ion exchange resin. 
     
     
         21 . The system of  claim 20 , wherein the apparatus configured to digest an alloy feed is configured to adsorb onto the chelating ion exchange resin less than 0.1% by weight of rhenium, relative to the amount of platinum adsorbed onto the chelating ion exchange resin. 
     
     
         22 . The system of  claim 1 , further comprising an apparatus configured to recover the platinum adsorbed onto the chelating ion exchange resin.