PRODUCTION OF MULTIPLE OXIDE POWDER

PURPOSE:To stably produce a multiple oxide powder containing a component such as zinc whose chloride has high vapor pressure, small in fluctuation of the conc. of a main component with lapse of time and small in chlorine content. CONSTITUTION:In the method for producing the multiple oxide powder consisting of a process (1) to spray a multiple chloride solution into a calcining furnace in the same direction as the flow direction of a high temp. gas which is a heating medium to induce calcining reaction, a process (2) to introduce the multiple oxide powder produced by the calcining reaction with a reactional product gas into a powder recovering device and to recover and a process (3) to recover hydrogen chloride gas in the reactional product gas as hydrochloric acid, roasting temp. is specified within 750-1000 deg.C and the diameter of a liquid drop in 90% volume accumulating distribution of the spraying liquid drop is specified to be