Abstract: Low cement high alumina silicon carbide castable was prepared with 83% rotary kiln bauxite，90% silicon carbide，α-Al 2O3 and silica fume as main raw materials，pure calcium aluminate cement as binder. This paper studied the effects of adding citric acid，boric acid and sodium fluorosilicate as retarders on the construction time，modulus of rupture and compressive strength of low cement high alumina silicon carbide castable. The results showed that the retarding effect of sodium fluorosilicate was the best，the modulus of rupture and compressive strength at ambient temperature decreased after 110 ℃ drying for 24 hours，while the modulus of rupture and compressive strength increased or decreased slightly after 1 100 ℃ and 1 400 ℃ heat treatment for 3 hours，therefore，boric acid or sodium fluorosilicate can be used as retarder in summer.

Key words: Low cement castable, Retarder, High alumina silicon carbide castable, Construction time, Modulus of rupture, Compressive strength