Abstract：Corundum-spinel composite powder were synthesized by solid state reaction at relatively low temperature using light-burned magnesia and commercial alumina as raw materials, and introducing a novel assistant agent OKU. The effect of amount of assistant agent and fired temperature on the phase compositionof the powders was investigated. The laboratory research results show that, adding assistant agent and rising calcining temperature can facilitate the spinel synthesizing reaction between MgO and Al2 O3. The MgO can be turned into spinel completely with 9 %assistant agent and be calcined at 1200 ℃ for 2 h. On the basis of laboratory research, an industrialized test of 100 kg grade spinel synthesizing by solid-phase reaction method with 9 % assistant agent at the temperature of 1 200 ℃ for 8 h was done. The chemical and phase composition and the particle size distribution of the products were tested. The rheological behavior of the slurry of corundum-spinel powders were also investigated. The industrialized test results indicated that, the phase composition of the powder includes spinel 27 % and corundum 73 %, without other phase. The medium diameter of the powder is 9.01 μm, and it reduced to 1.82 μm after ball milling for 4 h. The particle size distribution of the product and ball-milled powder are both bimodal distributions. The flow ability of the slurry with different solid content obeyes the law of non-Newtonian pseudo-plastic fluid. And their viscosity grows with the increasing solid content.

Keywords：solid state reaction; corundum-spinel composite powders; phase composition; particle size distribution; rheological property