Abstract: Based on the results of three kinds of water reducer solely added in refractory castable, and orthogonal test was used to determine the optimal mix ratio. According to the seven performance indexes of castable and result of analysis of scanning electronic microscope, optimal admixing quantity of composite water reducer was obtained. Exprimental results show that the water reducer has evident effect on water reducing, and the performance of refractory castable improves greatly when composite water reducer is in the the scope of 5‰-10‰.

Key words: refractory castable%compound water reducer%optimal admixing quantity