Process for the solvent extraction of palladium from aqueous solutions

Process for the solvent extraction of palladium from aqueous solutions of palladium salts which contain nitrate ions and are essentially free of halide and pseudohalide ions, comprising the following steps:

• (1) contacting the aqueous, palladium salt-containing solution with a solution of an extraction medium in a water-immiscible organic solvent;
• (2) separating the aqueous solution from the solution of the extraction medium in the water-immiscible organic solvent into which the palladium has been extracted;
• (3) contacting the resulting organic phase with an aqueous strip solution, the palladium transferring into the aqueous strip solution;
• (4) separating the aqueous strip solution, into which the palladium has transferred, from the solution of the extraction medium in the water-immiscible organic solvent;
• the extraction medium used being pyridinecarboxylic esters of the general formula (1) ##STR3## in which n=1 to 3 and R is identical or different hydrocarbon radicals having 5-36 C atoms and where the sum of the carbon atoms of all the Rs is between 16 and 36.