SYNTHESIS OF ULTRAFINE NICKEL POWDER BY CHEMICAL PRECIPITATION-REDUCTION METHOD

Synthesis of ultrafine nickel powder was investigated by chemical precipitation-reduction method with NiSO4 ·6H2O,ammonia and urea as the raw materials.The ultrafine nickel powder was characterized by means of FT-IR,XRD and SEM.It was found that the precursor synthesized by direct precipitation method was composed ofβ-Ni(OH)2 phase with irregular shape,however,the precursor synthesized by homogeneous precipitation method was a mixture of nearly sphericalα-Ni(OH)2 andβ-Ni(OH)2.Single phase nickel powder particles were synthesized by calcining the precursors resulted from the two precipitation method at 300℃for 1hin 90%Ar+10%H2 atmosphere.The nickel powder particles from the direct precipitation method were nearly spherical,and the particle size was 2-10μm.The particles from homogeneous precipitation method had nearly spherical alveolate structure and good dispersity,and the particle size was about 1μm.