Effect of Submicron SiO2 Powder Addition on Properties of Cement Free Iron Trough Castables

A new cement free iron trough castable was prepared with dense corundum and silicon carbide as the main raw materials and submicron SiO2 powder(d50=0.242 μm,SiO2=99.9 mass％)as the binder.The effect of the submicron SiO2 powder addition(3％,4％,5％,6％,7％,8％,and 9％,by mass,respectively)on the properties of the prepared castables was studied.The working mechanism of submicron SiO2 powder was analyzed from the perspective of the particle size distribution and infrared absorption spectrum.The results show that:(1)cement free iron trough castables can be prepared using submicron SiO2 powder alone as the binder;(2)compared with traditional castables,the cement free castables have made a breakthrough in the water addition and hot modulus of rupture.The optimal submicron SiO2 powder addition is 4％-6％.