物料配比对铝酸钙炉渣浸出和自粉性能的影响

将CaO,SiO2和Al2O3按不同配比混合,在1 500℃煅烧1 h、降温速度为5℃/min下合成了铝酸钙炉渣,主要物相为-γ2CaO.SiO2和12CaO.7Al2O3;并通过XRD和马尔文激光粒度仪研究了铝酸钙炉渣的C/A(除去和SiO2结合成2CaO.SiO2之外的n(CaO)/n(Al2O3))和A/S(w(Al2O3)/w(SiO2))对其物相组成和自粉性能的影响.结果表明:炉渣的C/A<1.5时有难浸物质钙铝黄长石2CaO.Al2O3.SiO2生成,降低了炉渣的浸出率和自粉性能,提高C/A可以消除其生成,C/A=1.6~1.9时,炉渣的浸出和自粉性能良好.炉渣的A/S对物相组成影...

Effect of Raw Material Mixture Ratio on Leaching and Self-disintegrating Behavior of Calcium Aluminate Slag

The calcium aluminate slag was synthesized by adjusting the raw material mixture ratio of CaO, SiO2 and Al2O3 through the calcinations at 1500°C for 1 h with 5°C/min cooling rate, where the main phases were γ-2CaO·SiO2 and 12CaO·7Al2O3. The effects of C/A (the molar ratio of CaO to Al2O3, excluding the CaO synthesized with SiO2 to form 2CaO·SiO2) and A/S (the mass fraction ratio of Al2O3 to SiO2) on the phase compositions and self-disintegrating behavior were investigated by XRD and a laser particle size analyzer. The results indicated that 2CaO·Al2O3·SiO2 is formed when C/A<1.5, which is difficult to leach Al2O3 thus reducing the leaching rate and self-disintegrating behavior of the slag. The increase in C/A ratio can inhibit the formation of 2CaO·Al2O3·SiO2, and the leaching rate and self-disintegrating behavior of the slag become better when C/A=1.6-1.9. The ratio A/S has little effect on the phase composition, and the leaching rate and self-disintegrating behavior of the slag become better when A/S=1.0-2.5. However, the leaching rate will decrease if the self-disintegrating behavior is degraded when A/S>2.5. As a result, the raw material mixture ratio of calcium aluminate slag in pure system is regarded as proper if C/A=1.6-1.9 and A/S=1.0-2.5.