Preparation of nano86.2W-13.1Fe-0.7Ni composite powder by combined EDTA-NH₃ complexing process

WO₃-Fe₂O₃-NiO precursor powder was prepared via the EDTA-NH₃ complexing process using nickel nitrate, ferrous nitrate and ammonium tungstate as raw materials, and SDS as surfactant. Then the nano 86.2W-13.1Fe-0.7Ni composite powder was prepared successfully at 800 ℃ for 60 minutes in H2 atmosphere. The effects of pH and reaction time in the mean particle size, morphology and composition of precursor were investigated. The results show that the reunited and nearly spherical WO₃-Fe₂O₃-NiO precursor in the average particle size of 1.16 μm and stable morphology could be obtained by reacting for 60 minutes at pH of 8.0. As a result, the nano 86.2W-13.1Fe-0.7Ni composite powder has an ellipsoidal particle morphology in a particle size of 80~100 nm, which is consisted of W and Fe₃Ni₂.