1. APPARATUS FOR THE PRODUCTION OF MICROSPHERICAL INORGANIC GEL PARTICLES WHICH COMPRISES IN COMBINATION, MEANS FOR CONTINUOUSLY MIXING HYDROSOL FORMING CONSTITUENTS, A PLURALITY OF REACTORS PROVIDED WITH AGITATOR MEANS, A DISPERSION MEDIUM STORAGE TANK, VALVE CONTROLLED CONDUIT MEANS FOR SUPPLYING DISPERSION MEDIUM FROM THE STORAGE TANK SUCCESSIVELY TO EACH OF THE REACTORS, VALVE CONTROLLED CONDUIT MEANS FOR SUPPLYING HYDROSOL SUCCESSIVELY TO EACH OF THE REACTORS, AN INLET LINE FOR DISCHARGING STEAM DIRECTLY INTO THE HYDROSOL INLET LINE JUST BEFORE EACH OF THE REACTORS DURING THE PASSAGE OF HYDROSOL THROUGH THE INLET LINE TO THE REACTOR, A DISPERSION LIQUID-WATER SEPARATOR, VALVE CONTROLLED LINES CONNECTED TO THE BOTTOM OF EACH OF THE REACTORS FOR DISCHARGING THE REACTOR CONTENTS INTO SAID SEPARATOR, OUTLET MEANS FOR THE WITHDRAWAL OF DISPERSION LIQUID FROM THE UPPER PART OF SAID SEPARATOR AND CONDUIT MEANS FOR RECYCLING THE DISPERSION LIQUID TO THE STORAGE TANK, OUTLET MEANS FOR THE WITHDRAWAL OF A SLURRY OF GEL PARTICLES IN WATER IN THE LOWER PORTION OF SAID SEPARATOR, MEANS FOR SEPARATING AND WASHING THE GEL PARTICLES, MEANS FOR RESLURRING AND AGING THE GEL PARTICLES AND MEANS FOR FILTERING, WASHING AND DRYING THE GEL PARTICLES.