Kinetic study on the hydrogen reduction of ferrous chloride vapor for preparation of iron powder

Abstract

A kinetic study on the hydrogen reduction of ferrous chloride vapor for the preparation of iron powder has been carried out both experimentally and theoretically. For the preparation of iron powder, ferrous chloride was vaporized and transported to a reaction zone by Ar gas used as a carrier. Ferrous chloride vapor and hydrogen were mixed and subjected to a reduction reaction at high temperatures to produce iron powders and HCl gas. Iron powder was collected with organic solvent at the end of reaction zone and HCl gas was also absorbed in a caustic soda solution to determine the conversion ratio of ferrous chloride. For the development of rate equations, a 1st-order reaction and equilibration of ferrous chloride vapor with Ar gas were assumed. According to the results, the rate constant, k, could be expressed as k=7879 exp(-53,840/RT) dm(3)/mol s and the activation energy was found to be 53.84 kJ/mol. From TEM observation, the particle size distribution of the iron powder produced was found to be in the range of 0.1-1.0 mu m which was not significantly influenced by the reaction temperature or the gas flow rate. (c) 2005 Elsevier B.V. All rights reserved.