Hoechst Aktiengesellschaft

Ruhrchemie Aktiengesellschaft

Dieter Kupies

Ludger Bexten

Boy Cornils

Peter Lappe

Jurgen Weber

Helmut Springer

Roderich Gartner

To separate and recover rhodium, the distillation residues of oxo synthesis products are initially treated with an oxidant. Then the reaction mixture is reacted, in the presence of carbon monoxide (or a compound which splits off carbon monoxide), with an aqueous solution of a reagent forming a water-soluble complex compound with rhodium. The reaction mixture breaks into an organic phase and an aqueous phase, the complex goes to the aqueous phase as it is substantially insoluble in the organic phase.

Process for the separation and recovery of rhodium from the products of

A process for recovering rhodium from an aqueous solution containing its complex compounds and optionally complex ligands in the presence of a water-soluble salt of a carboxylic acid by treatment of the aqueous solution at 20.degree. to 120.degree. C. with hydrogen peroxide (or a substance forming hydrogen peroxide) and with oxygen (or an oxygen-containing gas). The rhodium is then removed as a water-insoluble compound.

Process for recovering rhodium

A process for the recovery of rhodium from aqueous solutions of rhodium complex carbon atoms comprising adding a molar excess of a water-soluble salt of an organic carboxylic acid of 7 to 22 carbon atoms to an aqueous solution of a rhodium complex compound, treating the solution with an oxidant at 50.degree. to 200.degree. C. and recovering the rhodium as a water-insoluble compound.

Novel recovery process

A process for the purification of salts of at least one member of the group consisting of diphenylphosphine-phenyl-m-sulfonic acid, phenylphosphine-di-(m-phenylsulfonic acid) and triphenylphosphine-tri-(m-sulfonic acid) from aqueous solutions thereof comprising adding at least a molar equivalent amount of at least one member of the group consisting of di-(n-pentyl)-amine, di-(n-hexyl)-amine and water-soluble salts of said amines to an aqueous solution containing at least one member of the group consisting diphenylphosphine-phenyl-m-sulfonic acid, phenylphosphine-di-(m-phenylsulfonic acid), triphenylphosphine-tri(m-sulfonic acid) and salts thereof to adjust the pH value to .ltoreq.7, recovering the precipitate, washing the precipitate and dissolving the same in an aqueous basic solution.

Process for the purification of sulfonated aryl phosphines

To recover a hydroformylation catalyst system containing rhodium and phosphine, the aqueous solution containing the catalyst system is mixed with acid and then extracted with an amine which is dissolved in an organic solvent. The organic phase is separated and treated with the aqueous solution of an inorganic base, thereby recovering the catalyst in essentially pure form as an aqueous solution.

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Duisburg, Germany

Dieter Kupies