Chemical process for the recovery of metal from an organic complex

Abstract

A method for the recovery of a metal from an organic complex thereof, said method comprising treating the complex with a weakly acid aqueous solution of an alkali metal, an alkaline earth metal or ammonium chloride having a chloride content of at least 4 molar whereby said complex is decomposed and metal ions are transferred to the aqueous solution.

We claim: 
     
       1. A method for separating a metal selected from the group consisting of chromium, .[.manganese, cobalt.]. .Iadd.cadmium, nickel, calcium, magnesium, .Iaddend.copper, titanium, iron, zinc, germanium, arsenic, zirconium, niobium, molybdenum, ruthenium, palladium, silver, tin, tellurium, tantalum, tungsten, osmium, platinum, gold, mercury, lead, antimony, and bismuth from an organic complex thereof, said method comprising treating the complex with a weakly acid aqueous solution of an alkali metal, an alkaline earth metal or ammonium chloride having a chloride content of at least 4 molar and an acid strength of up to 0.5 molar above the stoichiometric requirement for stripping the metal whereby said complex is decomposed and metal ions are transferred to the aqueous solution. 
     
     
       2. A method according to claim 1 which comprises treating a solution of the complex in a water-immiscible organic solvent. 
     
     
       3. A method according to claim 1 wherein the solution of the complex in a water-immiscible organic solvent is a product of extracting an aqueous solution of metal salt with a solution of organic extractant in the water-immiscible organic solvent. 
     
     
       4. A method according to claim 3 wherein the organic extractant comprises an organophosphorus compound of the formula ##STR4## wherein R represents a branched alkyl radical containing at least 12 carbon atoms and which may optionally carry one or more substituents which are inert under the extraction conditions, and n is 0 or 1. 
     
     
       5. A method according to claim 4 wherein R is a branched alkyl radical containing at least 16 carbon atoms. 
     
     
       6. A method according to .[.claim 4 or.]. claim 5 wherein R is a radical of the formula: ##STR5## wherein R 1  and R 2  are straight-chain or branched alkyl radicals which together contain at least 14 carbon atoms and wherein R 1  contains 2 more carbon atoms than R 2 . 
     
     
       7. A method according to claim 6 wherein R is a radical of the formula: ##STR6## 
     
     
       8. A method according to claim 1 wherein the organic complex is a product of treating an aqueous solution of metal salt with a chelating resin. 
     
     
       9. A method according to any one of claims 1 to .Iadd.5 or 7 to .Iaddend.8 wherein the weakly acid aqueous solution of alkali metal, alkaline earth metal or ammonium chloride has a chloride content of at least 5 molar. 
     
     
       10. A method according to any one of claims 1 to .[.9.]. .Iadd.8 .Iaddend.wherein the organic complex is a complex of antimony or bismuth.