山西典型高铝煤灰熔融及黏温特性改性实验研究

以山西典型高铝煤为研究对象,研究了工业助熔剂石灰石、黏土以及两者的复合助熔剂对其灰熔融特性及黏温特性的影响。结果表明,随着助熔剂含量的增加,煤灰熔融流动温度下降;石灰石的助熔效果优于黏土,复合助熔剂效果优于单一助熔剂。添加石灰石使灰渣临界黏度温度tcv显著降低,添加黏土使其渣型向玻璃渣转变,复合助熔剂较单一助熔剂存在显著协同作用,即能同时实现tcv的降低和渣型的有利转变。对山西典型高铝煤两渡煤,在复合助熔剂添加量为4%(2%石灰石+2%黏土)时,不仅其渣型向玻璃渣转变,且tcv较单独添加石灰石(2%)降低133℃,较单独添加黏土(6%)降低222℃。矿物质分析结果证实了助熔剂的助熔原理。添加复合助熔剂改性的山西高铝煤可达到工业气流床气化对煤种的要求。

Study on ash fusion and viscosity temperature characteristics modification of Shanxi typical high aluminum coal

In this work, the influences of two industrial fluxes (i.e. limestone and clay) and their composite flux on ash fusion and viscosity temperature characteristics of Shanxi typical high-alumina coals were explored, respectively. The results indicated that flow temperature of coal ash decreased with increasing additive amount of flux. Moreover, limestone exhibited a better flux effect than clay, among which the flux effect of composite flux was more obvious than that of the single fluxes. It was also found that limestone could significantly reduce the t_cv of coal ash slag and clay could promote the slag type transformation towards glassy slag. Compared with single fluxes, composite flux exhibited synergistic effect on both the significant reduction of t_cv and the promotion of slag type transformation. For Shanxi typical high-alumina Liangdu coal, when total amount of composite flux was 4% (2% limestone+2% clay), not only the slag transformed into glassy slag, but also t_cv of the slag decreased 133 and 222 ℃ compared with single flux limestone(2%) and clay (6%), respectively. Minerals analysis results confirmed the fluxing principle of different fluxes. After the addition of composite flux, Shanxi high-alumina coals could meet the requirements of industrial entrained-flow gasifier.