Zirconium Carbide, ZrC

Zirconium resembles titanium in its power of combining with carbon at high temperature. Troost obtained a carbide to which he attributed the formula ZrC₂ by heating zircon with carbon in the electric arc in an atmosphere of carbon dioxide. Moissan and Lengfeld produced a carbide, similarly, by heating in an electric furnace a mixture of pure zirconia and sugar-carbon, mixed with oil and made into cylinders, which were placed in a carbon tube. The carbide was grey and metallic-looking, was well crystallised, was hard enough to scratch glass, but not ruby, had the composition ZrC, and was not decomposed by water at 0° C. or 100° C. In this latter respect it differs from thorium carbide, which, like the carbides of more electropositive metals, is decomposed by water with evolution of hydrocarbons. Wedekind has prepared this carbide from natural zirconia by a similar process, has shown that it is an excellent conductor of electricity, and that it is converted into the nitride when heated in a stream of nitrogen.