Abstract: Light-weight spinel refractories were prepared by solid phase sintering method with fused spinel fine powder，sintered magnesia powder and hollow magnesia alumina spinel balls as main raw materials. The effects of magnesia powder and hollow magnesia spinel balls on phase composition，microstructure，compressive strength and thermal conductivity of refractories were studied. The results showed that the introduction of magnesia powder（less than 5%）promoted the cambination of hollow balls and surrounding particals due to the solid dissolve in spinel and the formation of secondary spinel between hollow ball and spinel powder particles. Increasing the content of magnesia powder promoted the sintering，compactness and compressive strength of refractories. Addition of magnesia powder below 5% was conductive to obtain light-weight spinel refractories with the enhanced compressive strength (22.8 ～ 27.3 MPa)，the decreased size of pores and thermal conductivity [200 ～ 1 000 ℃，0.256 ～ 0.524 W/(m•K)].

Key words: Light-weight refractories, Hollow sphere, Magnesia powder, Magnesia alumina spinel