添加剂对高碱煤钠迁移和灰分烧结温度的影响

选取三种不同的添加剂（高岭土、SiO₂和Al₂O₃）,研究它们对高碱准东煤钠迁移和灰分烧结温度的影响,并且添加比例为1%-5%。结果表明,三种添加剂的钠捕集效率依次为：高岭土 > SiO₂ > Al₂O₃。钠捕集效率随着添加比例的增加而升高,但受温度影响比较复杂。高岭土的钠捕集效率在600-1000℃先增加后减小,并在900℃达到最大值,其余两种随温度的升高均减小。准东煤灰的烧结温度为803℃,添加高岭土后,烧结温度随添加比例的增加先降低后上升。当添加比例为3%时,因为钙长石和钙黄长石的低温共熔反应而达到最小值。SiO₂的添加比例为5%时,由于透辉石的生成和SiO₂本身的"骨架"作用,烧结温度迅速升高到879℃。Al₂O₃对烧结温度的影响最小。

Influence of additives on sodium release and ash sintering temperature of a high-alkali coal

The influence of three additves (Kaolin, SiO₂ and Al₂O₃) on sodium release and ash sintering temperature of high-alkali Zhundong coal with addition ratio range of 1%-5% was studied. The results indicate that the order of sodium capture efficiency for the additives is:Kaolin > SiO₂ > Al₂O₃. The sodium capture efficiency increases with the addition ratio. However, the effect of temperature is much complex. At 600-1000℃, the sodium caputre efficiency of Kaolin increases firstly and then decreases, and the maximum value is achieved at 900℃. Meanwhile, the sodium capture efficiencies of other two additives decrease with increasing temperature. In addition, the ash sintering temperature of Zhundong coal is 803℃. After adding Kaolin, it decreases firstly and then increases with the addition ratio. At the addition ratio of 3%, the sintering tempeature is lowest due to the low-melting eutectic reaction between gehlenite and anorthite. SiO₂ with 5% can increase the sinntering temperature to 879℃ sharply because of generation of diopside and its skeleton effect. The influence of Al₂O₃ on the sintering temperature is minimal.