关键词: 煤渣, 浸取, 液态排渣, 回收, 固体废弃物

Abstract: In order to solve the high added value utilization problem of liquid drain slag，residual carbon particles and vitreous material of coarse slag from coal water slurry gasification furnace were separated by water washing. Their compositions and structures were determined using elemental analyzer，calorimeter，inductively coupled plasma emission spectrometer and X-ray diffracmeter. The extraction methods of SiO2 and the influence of particle size，reaction liquid concentration，reaction liquid-solid ratio，reaction temperature and reaction time on the extraction rate of Fe and SiO2 in vitreous material by leaching with hydrochloric acid and sodium hydroxide solution separately were studied. Elemental analysis showed that C accounted for more than 63% in residual carbon. The net calorific value of residual carbon exceeded 21MJ/kg on dry basis. Vtreous material with 93.47% of Si，Al，Ca and Fe oxides was amorphous and was easy to react with acid. By this way，more than 90% of Fe and 93% of SiO2 were extracted from vitreous material and almost 92% of solid waste discharge were reduced.

Key words: coal slag, leaching, liquid drain slag, recovery, solid waste