MOVING BED PROCESS FOR CARBOTHERMALLY SYNTHESIZING NONOXIDE CERAMIC POWDERS

摘要

Carbothermally reduce a metal oxide to its corresponding metal nitride or metal carbide powder in a vertical gravity flow reactor (11) by adding pr ec- ursor pellets containing the metal oxide, a thermally decomposed binder mate - rial, and carbon or a source of carbon, directly to a heated reaction zone (31) within the reactor. The pellets form a pellet bed (19). The top of the bed (18) must be maintained within the heated reaction zone. The binder material is a blend of wheat and corn starches. The binder material thermally decomposes to a carbonaceous residue that functions both as an additional source of car - bon and as a binder for the precursor pellets.