Evaluation of aluminum dross as raw material for high-alumina refractory

摘要

We report on the preparation of high-alumina refractory (HAR) from metallurgical aluminous dross with main crystalline phase of MgAl_2O_4 and small amounts of CaAl_2O_4. Samples were characterized using X-ray diffraction, scanning electron microscopy and petrographic analysis. Physical properties such as bulk density, apparent porosity and compressive strength of HAR were investigated. Magnesium aluminate spinel, calcium monoaluminate (CaAl_2O_4) and calcium bialuminate (CaAl_4O_7) were the primary phases of the obtained HAR. CaAl_4O_7 was generated after sintering and formed a matrix to bind the separated magnesia-alumina spinel effectively, which could improve the compactness of the samples. Ti promoted the propagation velocity of phase particles, and could reduce the extent of oxidation and improve HAR product compactness. The as-prepared HAR met the Chinese National Standard (GB/T 2988-2004), indicating its potential application in the refractory field.