Abstract: Effects of single and composite coagulants on setting rate and hardening rate of pure calcium aluminate cement were studied,as well as the influence of mass ratio of NaOH and NaAlO2 in composite coagulants on properties of alumina-spinel castable with 4wt% cement.The results show that the effects of Li2CO3 and LiOH on coagulation of cement were more obvious than NaAlO2 and NaOH,and the setting time could be shortened by adding more coagulants.The composite coagulants with different mass ratios of NaOH and NaAlO2 could speed up the setting rate and hardening rate.However,the bending strength,compressive strength and thermal shock resistance declined because of Na+ from coagulants,while bulk density,apparent porosity and slag corrosion resistance of castable changed little.