Process for removing precious metal from precious metal-containing catalyst form bodies

A process for removing a precious metal from precious metal-containing catalyst form bodies comprising form bodies and a precious metal, whereby the precious metal to be removed is at least one precious metal selected from the group consisting of Au, Ag, Pd, Pt, Ir, Rh, Ru, Os, and Re, comprising the steps of:

• (a) producing, in a reaction vessel, a mixture of the precious metal-containing catalyst form bodies in at least one mineral acid that is at least 1N;
• (b) supplying an inert or oxidising gas into the mixture containing the precious metal-containing catalyst form bodies and the at least one mineral acid;
• (c) introducing at least one oxidation agent, in solid or liquid form, into the mixture containing the precious metal-containing catalyst form bodies and the at least one mineral acid, the at least one oxidation agent being introduced into the mixture in a lower half of the reaction vessel;
• and
• (d) separating the form bodies from the mixture,
• wherein step (a) precedes steps (b) and (c).