不同焙烧法对煤矸石中铝浸出效果的影响

Effect of Different Methods of Calcining on Extraction Efficiency of Aluminum from Coal Gangue

煤矸石中铝的溶解性质不仅受焙烧温度的影响,与焙烧方式也密切相关。通过X衍射分析研究了直接焙烧时,煤矸石中矿物成分的变化以及温度对主要含铝矿高岭石物相转化的影响,结合铝的溶出试验,确定在700℃焙烧,用氢氧化钠碱液可将煤矸石中95%以上的铝溶出。采用石灰石法时,铝的溶出效果受焙烧温度和石灰石与煤矸石的配比影响。在较低的温度即600℃,当石灰石与煤矸石配比在2.06时,铝的溶出率也可达90%以上,在温度为900℃,当石灰石与煤矸石配比大于理论计算值时,铝的利用率可达99%。

The solubility property of aluminum in coal gangue is influenced by the calcination temperature as well as the way of calcination. X-ray was applied to research the changes of composition in coal gangue and effect of temperature on conversion of kaolinite. The results showed that 95% of aluminum could be extracted from coal gangue which was calcined at 700 ℃ followed by dissolved using sodium hydroxide solution. When coal gangue was calcined with limestone, the extraction efficiency of aluminum was influenced by the roasting temperature and the ratio of limestone to coal gangue. At the lower temperature of 600 ℃ with ratio of 2.06 the dissolving efficiency of aluminum was more than 90%. The extraction efficiency of aluminum could reach to 99% when the calcination temperature was 900 ℃ and the ratio was higher than theoretical value.