不同Si/Al条件下Na_(2)O对煤灰熔融温度及硅酸盐结构的影响  

Effect of Na_(2)O on Ash Fusion Temperature and Silicate Structure under Different Si/Al Ratio

作　　者：张星照 李寒旭[1] 焦发存 夏宝亮 ZHANG Xingzhao;LI Hanxu;JIAO Facun;XIA Baoliang(School of Chemical Engineering,Anhui University of Science and Technology,Huainan 232001,China)

机构地区：[1]安徽理工大学化学工程学院,安徽淮南232001

出　　处：《煤炭技术》2023年第10期262-266,共5页Coal Technology

基　　金：安徽高校自然科学研究重点项目(KJ2020A0278);安徽省科技重大专项项目(202003a07020022)。

摘　　要：以淮南本地高灰熔点煤为原料,通过调控煤灰硅铝比,改变煤灰中Na_(2)O含量,利用灰熔点测定仪、XRD及FTIR,探究Na_(2)O对不同硅铝比条件下煤灰熔融温度及硅酸盐结构的影响。实验结果表明:Na_(2)O明显改善煤灰熔融温度,且对高硅铝比煤灰影响较为显著,对低硅铝比煤灰熔融温度呈先降低后增加趋势,氧化钠含量为15%、Si/Al=2.0时煤灰流动温度(TF)降至最低,为1 292℃。不同硅铝比条件下原煤灰主要矿物为石英,在高温下煤灰中的Na_(2)O会与灰中的SiO2,Al2O3反应生成熔融温度较低的霞石,导致煤灰熔融温度的明显降低。Na_(2)O含量增加会导致架状和层状硅酸盐结构解聚形成更多的链状硅酸盐结构和环状硅酸盐结构,促进煤灰由复杂结构向简单结构转化。The effect of Na_(2)O on the ash fusion temperature and silicate structure of coal ash under different silica-alumina ratio conditions was investigated by regulate the silica-alumina ratio and the Na_(2)O content in coal ash, using ash melting point tester, XRD and FTIR. The experimental results showed that Na_(2)O had a significant effect on changing the melting temperature of coal ash, and the effect on high Si/Al ratio coal ash was more significant, and the melting temperature of coal ash showed a trend of first decreasing and then increasing for the increase of Na_(2)O content of low Si/Al ratio coal ash. The lowest coal ash flow temperature(TF) was 1 292°C at 15% Na_(2)O content and Si/Al=2.0. The main minerals of raw coal ash under different Si/Al ratios are quartz, and the Na_(2)O in coal ash will react with SiO2and Al2O3in the ash to form nepheline with lower melting temperature at high temperature,leading to a significant decrease in the melting temperature of coal ash. The increase of Na_(2)O content will lead to the depolymerization of shelf and laminated silicate structures to form more chain silicate structures and ring silicate structures, and promote the transformation of coal ash from complex to simple structures.

关 键 词：硅铝比 氧化钠 灰熔融温度 硅酸盐结构 

分 类 号：TQ536.4[化学工程—煤化学工程]