With satisfactory high temperature properties, thermal shock resistance and mechanical properties, refractories in the MgO˗Al2O3 system have become promising alternative to MgO-Cr2O3 counterpart used as RH snorkel lining. High purity dead burned magnesia, fused magnesia and sintered spinel were used as raw materials and sulfite pulp waste as the binder, specimens of the refractories in the MgO-Al2O3 system were prepared for the purpose of investigating the influences in terms of the addition of three kinds of spinels, with Al2O3 50%, 66% and 78%, by mass, respectively, and the size of MA50 spinel on properties of the specimens. Relatively superior comprehensive properties can be achieved when 16% of MA50 spinel with sizes under 1 mm is adopted.