PROCESS FOR RECOVERING NOBLE METALS BELONGING TO GROUP VIII OF THE PERIODIC SYSTEM OF THE ELEMENTS FROM A CONTAMINATED CATALYST SOLUTION ORIGINATING FROM THE CARBONYLATION OF METHYL ACETATE AND/OR DIMETHYLETHER

摘要

PROCESS FOR RECOVERING NOBLE METALS BELONGING TO GROUP VIIIOF THE PERIODIC SYSTEM OF THE ELEMENTS FROM A CONTAMINATEDCATALYST SOLUTION ORIGINATING FROM THE CABONYLATION OF ME-THYL ACETATE AND/OR DIMETHYLETHERABSTRACT OF THE DISCLOSUREThe disclosure relates to a process for recoveringnoble metals belonging to group VIII of the Periodic Systemof the elements from a contaminated catalyst solution origi-nating from the carbonylation of methyl acetate and/or di-methylether, the catalyst solution containing carbonyl com-plexes of these noble metals, organic compounds of the ni-trogen group and/or salts of alkali metals, alkaline earthmetals, chromium, iron, cobalt or nickel as promoters,un-distillable organic contaminants as well as acetic acid,acetic anhydride and ethylidene diacetate, wherein the vo-latile constituents are distillatively removed from thecatalyst solution and the remaining distillation residue iswater-treated, whereby the noble metal/carbonyl-complex isprecipitated together with the organic contaminants and isseparated from the aqueous phase, whilst the promotor isdissolved and recovered in conventional manner. To this end,the disclosure provides for the noble metals to be set freein elemental form by subjecting the noble metal/carbonyl-complex separated and contaminated with organic polymers attemperatures of 150 to 300°C to treatment with an ethylene-glycoldialkylether of the formula R(-OCH2-CH2)n-OR, inwhich n stands for a number of from 1 to 4 and R stands foridentical or different alkyl groups having from 1 to 6 car-bon atoms, for the noble metals so set free to be recoveredby filtration and, after distillative removal and recoveryof the solvent, for the organic contaminants initially re-tained in the solvent to be removed.