高岭土对准东煤中不同赋存形态钠释放的影响

Effect of kaolin on sodium release of different forms in Zhundong coal

新疆准东煤中碱金属钠含量较高,大量碱金属钠的释放可能会引起设备结渣和腐蚀等安全问题,甚至对电厂的安全运作产生了严重的影响。由于高岭土主要含有硅铝氧化物,可以吸收准东煤中的碱金属,从而达到防止准东煤结渣的作用。采用热分析的方法,对添加高岭土前后的五彩湾煤、天池能源煤、乌冬煤以及其对应的水洗煤的钠释放量随温度变化进行了研究,分析了高岭土对准东煤中不同赋存形态钠释放的影响规律。结果表明:当准东煤中加入10%高岭土,煤中钠的释放量明显降低,说明高岭土具有抑制钠释放的作用;在准东水洗煤中添加10%的高岭土可以显著减少其中钠的释放率,如果温度达到1100℃,钠释放率分别在五彩湾、天池能源以及乌东水洗煤中下降的比例为11.94%、28.36%以及30.6%,由此可见,高岭土对具有较高释放量的有机钠的释放具有非常突出的抑制作用;除此之外,高岭土同样可以明显抑制准东煤中水溶性钠的释放,当其中高岭土的添加量为10%,温度达到1100℃时,水溶性钠释放率分别在五彩湾煤、天池能源煤以及乌东煤中下降的比例为68.96%、58.37%以及55.3%,由此可见,当高岭土添加量为10%时,煤中水溶性钠的释放量最少会减一半。

The content of alkali metal sodium in Zhundong coal in Xinjiang is high, and the release of a large amount of alkali metal sodium may cause safety problems such as equipment slagging and corrosion, and even has a serious impact on the safe operation of power plants. Since kaolin mainly contains silicon-aluminum oxide, it can absorb alkali metal in Zhundong coal, which has certain effect on preventing Zhundong coal slagging. Therefore, this paper uses the method of thermal analysis to study the sodium release of the Wucaiwan coal, Tianchi energy coal, Wudong coal and their corresponding washed coal before and after the addition of kaolin, and analyzes the effect of kaolin on sodium release of different forms of Zhundong Coal. The results show that when 10% of kaolin was added to Zhundong coal, the release of sodium in coal was significantly reduced, indicating that kaolin had the effect of inhibiting sodium release;when 10% of kaolin was added to Zhundong washed coal, the release rate of washed coal was significantly reduced. At 1100 ℃, the release rate of sodium in the Wucaiwan washed coal was reduced by 11.94%, in Tianchi energy washed coal by 28.36%, and in Wudong washed coal by 30.6%. The higher the release of organic sodium was, the more obvious the inhibition effect of its release was after kaolin addition;the addition of 10% of kaolin in Zhundong coal had a strong inhibitory effect on the release of water-soluble sodium. At 1100 ℃, the release rate of water-soluble sodium in Wucaiwan coal decreased by 68.96%, in Tianchi Energy Coal by 58.37%, and in Wudong coal by 55.3%. The addition of 10% of kaolin could reduce the release of water-soluble sodium by at least half.