利用XRD和FT-IR考察了高温弱还原气氛下Na2 O对两种硅铝含量不同的煤灰中矿物质组成的影响，揭示了Na2 O影响煤灰熔融特性的本质。通过FactSage计算了高温下矿物质反应的ΔG，探讨了Na2 O影响煤灰中矿物质组成的机理。结果表明，Na2 O对煤灰矿物质组成的影响与原煤灰的硅铝含量密切相关。硅铝总含量82．89％的煤灰，Na2 O含量为5％－20％时，钠长石和霞石的生成是煤灰熔融温度降低的主要原因；当Na2 O含量大于20％时，导致煤灰熔融温度降低的原因是霞石的生成。硅铝总含量47．85％的煤灰，Na2 O含量小于10％时，没有含钠矿物质生成；当Na2 O含量大于10％时，主要生成菱硅钙钠石、青金石和含钠的硅铝酸盐矿物，导致煤灰熔融温度降低。 FactSage计算表明生成含Na矿物质反应的ΔG较小，其在高温下更容易发生。%In ordre to er ve al the mechna ism of Na2O influence on ash fusoi n tem peratures (AFTs), effect of Na2 O on mineral transfor mation of two coal ashes with different SiO2+Al2 O3 leev ls wre e investgi ated by XRD and FT-IR udn er reducing atmosphere at high temperature.Thermodynamic os ftware package FactSage was used to ac lculate the ΔG of reactions between minerals to reveal the mechanism of Na2 O influence on mineral trna fs ormation.It is found tah t the effect of Na2 O on mineral oc mpositions depends on SiO2+Al2 O3 levels of coal ash.For ash wi th 82.89% SiO2+Al2 O3 while Na2 O content is 5%-20%, albite and nepheline are formed, leading to a decrease of AFTs.However, only nepheline is formed when Na2 O content is higher than 20%.For ash with 47.85% SiO2+Al2 O3 , when Na2 O content is less than 10%, no Na-containing mineral is observed. When Na2 O content is higher than 10%, Na-containing minerals such as combeite, lazurite and sodium aluminium oxide are formed, resulting in a decrease of AFTs.Furthermore, FactSage results reveal that Na-containing mineral is easily formed at high temperature due to lowΔG of the reactions.
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