Process for the production of ammonium perrhenate

Process for the production of ammonium perrhenate, comprising the following steps:

• a) providing an aqueous suspension comprising rhenium-containing compounds;
• b) adding Ca(OH)2 to the suspension from step a), the pH value being greater than 7;
• c) adding an oxidizing agent to the aqueous suspension from step b), the temperature of the suspension not exceeding 50° C.;
• d) heating the suspension from step c) to at least 95° C. and subsequent filtration, the suspension being cooled to 60° C. or less prior to filtration;
• e) adding an ammonium carbonate to the filtrate from step d) to obtain an aqueous suspension containing ammonium perrhenate;
• f) filtering the suspension from step e);
• g) reducing the amount of liquid of the filtrate from step f) to obtain solid ammonium perrhenate.