A process for preparing silicon carbide by carbothermal reduction which includes transporting, in a gaseous medium, a particulate reactive mixture of a silica source and a carbon source through a reaction zone. The heating rate of the atmosphere within the reaction zone is such that substantially all of the reactive mixture is heated at a heating rate of at least about 100.degree. C./second until an elevated temperature of at least 1800.degree. C. is reached. Either (1) carbon monoxide is added to the reaction zone or (2) a carbon monoxide level in the reaction is achieved in order to provide at least about 30 mole percent of the gases exiting the reaction zone to achieve a higher yield of silicon carbide.