低品位煤矸石制备莫来石的研究

以酸洗处理后的南方地区煤矸石及氧化铝为原料,研究了不同试验条件下合成莫来石物相的影响。结果表明:1 200℃开始有棒状莫来石晶体的生成,1 500℃以后莫来石大量生成,温度升高到1 600℃莫来石进一步生成;改变最高温度下的保温时间,莫来石化程度呈现先增后减的趋势;改变煤矸石的用量,随着煤矸石用量的增加,物相中刚玉峰增强,说明煤矸石用量的增加不利于莫来石的合成;改变配料中的铝硅比,由3∶2降低到1∶1过程中,莫来石化程度逐渐加强,在铝硅比1∶1时物相中刚玉峰消失,说明低品位煤矸石在较低的铝硅比下有利于莫来石的合成。

Study on Preparation of Mullite from Low Grade Coal Gangue

Using the coal gangue after acid leaching and alumina oxide as raw material,the effect of syn thetic on mullite phase was researched under different experimental conditions.When the heating temperature is 1 200 ℃ a rod like mullite crystal appears,.With the temperature exceeding 1 500 ℃,significant amount of mullite is obtained and its amount further increases while temperature reaching up to 1 600 ℃.By changing the holding time under highest heating temperature,the degree of mullitization firstly increa ses and then decreases.With the coal gangue dosage increasing,corundum phase peak enhances,which indicates that the increase of coal gangue dosage has negative role in synthesizing mullite.By changing the rate of silicon and aluminum from 3 ∶ 2 to 1 ∶ 1,the degree of mullitization gradually enhances.When the ratio of silicon and aluminum is 1 ∶ 1,corundum phase peak disappears,which indicates that low-grade coal gangue with lower alumina-silica ratio is beneficial for the synthesis of mullite.