気相反応法により生成するニッケルおよびモリブデン微粉体の粒度

概要

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Ultrafine particles of nickel and molybdenum were prepared by hydrogenation of metal chloride in the gas phase. The effects of operation conditions such as reaction temperature and concentration of metal chloride on the particle size were investigated. Particles were characterized by means of transmission electron microscopy, X-ray diffraction and BET surface area.<BR>The size of nickel particles decreased with increasing temperature in the range of 1050-1250K but increased with increasing temperature above 1250K. Near the melting point, the particle size obeyed the agglomeration theory which assumes that each particle fused immediately after mutual collision by Brownian motion.<BR>The fusion of particles was possible even at relatively low temperatures when the particles were small. Particle growth by fusion was enhanced if metal monomer could deposit near the neck of agglomerated particles. After the disappearance of metal chloride, however, the rate of particle growth became very slow. Nickel chloride was consumed within 0.3 second under the present conditions.<BR>Particle size was decreased by an increase in the rate of hydrogenation reaction.
社団法人化学工学会の論文