Investigating the Kinetics and Features of the Reduction Mechanism of Ammonium Paramolybdate in Hydrogen—Nitrogen Media

摘要

Kinetic features of the reduction of ammonium paramolybdate in pure hydrogen and in a mixture of hydrogen and nitrogen with a ratio of 1 : 0.5—1.0 in the temperature range of 250-950°C with a gas supply rate of 1—3 L/min are investigated. The optimum conditions for performing this process in hydrogen—nitrogen media that ensure a no lower than 90% recovery of the target phase are established. The evolution of forming the nano- and microcrystalline molybdenum powders via the reduction of ammonium paramolybdate in hydrogen—nitrogen media is investigated. The dependence of the granulometric composition and morphology of powder samples on the type of the reduction atmosphere is shown. During high-temperature (880—900°C) reduction in a hydrogen—nitrogen medium (composition, 1:1), numerous crystallization centers with the formation of molybdenum grains through pseudomorphic transformation are observed in the powders.