Production of fused alumina

Claim 1

IN A PROCESS OF PREPARING FUSED ALUMINA BY CALCINING SUBSTANTIALLY PURE ALUMINA HYDRADE TO CONVERT SUCH HYDRATE TO ALUMINA AND THEREAFTER FUSING THE CALCINED ALUMINA AND OBTAINING A SOLIDIFIED FUSED PRODUCT, THE IMPROVEMENT IN SAID PROCESS, TO INHIBIT DARKENING OF SAID ALUMINA UPON SAID FUSING THEREOF, WHICH CONSISTS IN PERFORMING THE SAID CALCINING OF THE SAID ALUMINA HYDRATE AT A TEMPERATURE OF ABOUT 1000*C. TO ABOUT 1550*C. TO CONVERT IT TO UNFUSED ALUMINA WHILE MAINTAINING IT IN A REDUCING ATMOSPHERE CONTANING ABOUT 0.5% TO 6* TOTAL OF CARBON MONOXIDE AND HYDROGEN, SAID CALCINING CONSISTING IN HEATING THE SAID SUBSTANTIALLY PURE ALUMINA HYDRATE BY DIRECT FLAME PRODUCED BY OIL FUEL AND CONTROLLED IN MUTUAL SUPPLY OF FUEL AND AIR TO PROVIDE SAID REDUCING ATMOSPHERE AND TO YIELD A WHITE UNFUSED ALUMINA WHICH DOES NOT DARKEN SUBSTANTIALLY ON THE AFORESAID FUSING THEREOF.