Effect of Different Binders on Properties of High Alumina Refractory Plastic

    The effect of different additives on the phase transformation and mocro-morphology of high alumina bauxite was investigated by 

means of X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The results indicated that the best particle size 

gradation is determined, which is 3-1 mm/ ≤mm/ ≤0.074 mm =47/18/25. The proportion of soft clay is 10% in aggregate. The 

combined strength of alumina plastic material combined by hexametaphosphate and sodium silicate is better than that of plastic 

materials combined by aluminum sulfate and aluminum dihydrogen phosphate. Because of additives containing Na^ ＋ and Ca^2 

＋, the samples inhibited the formation of mullite in the sintering process. At the same time, owing to the formation of glass phase,

 the densification of sintered samples was enhanced, but the porosity was decreased. As a result, the properties of this material is 

worse at high temperature, on the contrary , better at room temperature.