关键词: 煤矸石;矿物质;碳热还原反应;SiC;Sialon

Abstract: Producing refractory material by coal gangue is one of the effective ways to realize the high-value utilization of coal gangue.The carbothermal reduction reaction of mineral matters in Pingshuo coal gangue at high temperature(1200-1500 ℃)under different atmospheres and effect of atmosphere on the mineral transformation were investigated by X-ray diffraction and scanning electron microscopy.Results show that the mullite in high-temperature coal gangue samples reacts with carbon to form moissanite (SiC)above 1300℃under argon atmosphere;while,the mullite transforms to β-Sialon(Si5AlON7)and corundum(Al2O3)above 1300 ℃ under nitrogen atmosphere.The formation of moissanite in samples could accelerate the transformation of mullite to β-Sialon when the coal gangue was firstly heated under argon atmosphere and then was heated continuously under nitrogen atmosphere.The moissanite and β-Sialon were difficult to be formed simultaneously in the coal gangue with low carbon content at high temperature.The β-Sialon in the high-temperature samples presents rod shape.

Key words: coal gangue;mineral matter;carbothermal reduction reaction;SiC;Sialon