Proposal for a new mechanism for the transformation of alumina into aluminium nitride

It is known that carbonitridation is a more efficient process than direct nitridation for the transformation of alumina into aluminium nitride. The simple mechanical mixture of carbon and alumina reduces both the temperature and time of reaction. However, the role of the carbon and the mechanism of the transformation are not clearly established. Evidence of the formation of hydrogen cyanide from the reaction of carbon with ammonia, and the gas-solid reaction between HCN and alumina for the synthesis of AlN is presented.