PURPOSE: To efficiently recover noble metal by reacting an OH-coordinated metal complex in a soln. with predetermined chlorate ions to substitute chlorine for the ligand prior to reduction and then adding a reducing agent.

CONSTITUTION: Noble metal ions dessolved in an acid is allowed to be adsorbed onto an ion exchange resin and passed through a conc. NaOH soln. to elute the ions as an OH-coordinated metal complex. Next the complex is reacted with at least one of hypochlorite and perchlorate ions such as sodium hypochlorite to be converted into chlorine-coordinated one. A reducing agent such as hydrazine is then added to the soln. to recover noble metal or metal black. The metal in the above complex is desirable to be Pt, Pd, Rh, Ru, Ir or Os.