Preparation of refractory oxide microspheres

Claim 1

THE METHOD OF PREPARING FUSED SPHERICAL OXIDE PARTICLES HAVING A DIAMETER WITHIN THE RANGE OF 1 TO 2 MICRONS WHICH COMPRISES INTRODUCING A DISPERSED STREAM OF A COMBUSTIBLE ORGANIC SOLUTION CONTAINING DISSOLVED THEREIN A MAJOR PROPORTION OF THORIUM NITRATE AND A MINOR PROPORTION OF REFRACTORY-OXIDE-FORMING VALUES INTO A REFLECTED OXYGEN-FED FLAME AT A TEMPERATURE ABOVE THE MELTING POINT OF THE RESULTING PARTICLES AND RECOVERING SAID PARTICLES, SAID REFRACTORY-OXIDE-FORMING VALUES BEING SELECTED FROM THE GROUP CONSISTING OF SILICON AT A PROPORTION SUFFICIENT TO PROVIDE 1 TO 10 WEIGHT PERCENT SILICON DIOXIDE IN SAID PARTICLES, ALUMINUM AT A PROPORTION SUFFICIENT TO PROVIDE 1 TO 10 WEIGHT PERCENT ALUMINUM OXIDE IN SAID PARTICLES AND BERYLLIUM AT A PROPORTION SUFFICIENT TO PROVIDE 12 TO 25 WEIGHT PERCENT BERYLLIUM OXIDE IN SAID PARTICLES.