Preparation of aluminum nitride

Claim 1

A PROCESS FOR PREPARING ALUMINUM NITRIDE, WHICH PROCESS COMPRISES FORMING A MIXTURE CONSISTING OF FINELY DIVIDED ALUMINUM IN AN AMOUNT OF FROM ABOUT 30 TO ABOUT 60 PERCENT BY WEIGHT AND FROM ABOUT 70 TO ABOUT 40 PERCENT BY WEIGHT FINELY DIVIDED CARRIER MATERIAL SELECTED FROM THE GROUP CONSISTING OF ALUMINUM NITRIDE, ALUMINUM FLUORIDE, AND MIXTURES THEREOF, PROVIDING AROUND SAID MIXTURE A NITROGEN ATMOSPHERE, HEATING SAID MIXTURE TO A TEMPERATURE BETWEEN ABOUT 800*C. AND ABOUT 1300*C WHILE UNDER SAID MIXTURE TO FORM ALUMINUM NITRIDE, AND THEN HEATIN SAID MIXTURE TO A TEMPERATURE BETWEEN ABOUT 1900*C. AND ABOUT 2100*C. UNDER AN ATMOSPHERE OF AN INERT GAS AT LEAST DURING TEMPERATURES ABOVE 1900* C., THEREBY SUBLIMING ANY ALUMINUM FLUORIDE PRESENT AND STABILIZING THE REACTION PRODUCT.