Research on the preparation of Ni/Al 2 O 3 powder by fluidized crystallization granulation–hydrogen reduction

Abstract This paper proposes a new process route for the preparation of Ni/Al 2 O 3 composite powder through fluidized crystallization granulation–hydrogen reduction and investigates the effects of process feasibility, nickel concentration, nucleation method, and hydrogen reduction on Ni/Al 2 O 3 ‐coated powder. The decrease in nickel concentration, heterogeneous nucleation, and natural air‐drying properties of precursor particles was beneficial to the formation of a complete and uniform cladding layer, and the increase in hydraulic retention time could improve the thickness of the cladding layer. The optimum process involves a nickel concentration of 50 mg/L; hydraulic residence time of 75 h to ensure heterogeneous nucleation; two‐step hydrogen reduction of precursor particles to obtain a complete and uniform Ni/Al 2 O 3 cladding layer; and a powder surface nickel content of 59.5%.