Iron carbide fine particles and process for preparing the same.

摘要

Iron carbide fine particles consisting essentially of iron carbide, which are characterized in that, in the step of the variation of the weight under the condition of combustion, the increase of the weight in the equilibrium after arrival at the maximum weight is 22% or less, on the basis of the weight before combustion. In which (a) after fine particles of iron oxyhydroxide or iron oxide have been or have not been contacted with a reducing gas containing no carbon atom, (b) the particles are contacted with a carburizing gas or a mixture of a carburizing gas and a reducing gas containing no carbon atom at a temperature of from 250 to 395 DEG C to prepare iron carbide fine particles, and (c) the resulting iron carbide fine particles are contacted with a carburizing gas at a temperature higher than the said temperature by 5 to 20 DEG C for 0.5 to 5 hours.