Kinetic Study on the Hydrogen Reduction of Some Nonferrous Metal Oxides

Abstract

To investigate the kinetic aspects in reactions involving solids, the reduction rate of nickel oxide by hydrogen was measured by means of thermo-balance. The rate is described by 2/3 order kinetic law and has an activation energy of 25 kcal/mol.. From the results of Delmon's interruption technique and other kinetic examination, it may be assumed that the reduction will proceed according to the spherical surface contracting model. The reduction rate of several ilmenite ores was also measured by the same means and the profiles of oxygen concentration in a section of reduced particles were examined by means of X-ray micro-analyser to inspect the reduction progress. It was found that the reduction process consists of two stages proceeding successively, where in the first stage, the reduction of iron oxide besides ilmenite component occurred, secondly, the latter component was reduced and those kinetics were also described approximately by 2/3 order law.