钙基固硫剂在煤泥燃烧中的变化及固硫效果研究
Transformation and performance of calcium-based sulfur retention agents during coal slime combustion
-
摘要: 为降低煤泥燃烧过程SO2排放,以煤泥为原料,分别利用X射线衍射仪（XRD）和电感耦合等离子体发射光谱仪（ICP）分析煤灰中矿物组成和化学组成,研究了2种钙基固硫剂（CaCO3、CaO）在煤泥燃烧过程中的演变行为和不同条件下的固硫效果。结果表明,当燃烧温度低于820℃时,2种固硫剂在燃烧过程中均主要转化为硬石膏和石灰,不与煤泥中的矿物质发生反应。当燃烧温度高于820℃时,固硫剂转化为硬石膏和生石灰,而生石灰又与煤灰中的SiO2和Al2O3反应生成了钙黄长石。当燃烧温度超过1 000℃时,部分固硫产物CaSO4发生分解,导致固硫率降低。煤泥和固硫剂混合制备成型煤,能够显著提高固硫效果。Abstract: To decrease the emission of SO_2 during coal slime combustion,the mineral composition and chemical composition of coal ash were analyzed using XRD and ICP.The transformation and sulfur capture efficiency of CaCO_3 and CaO during coal slime combustion were investigated.When the temperature was lower than 820 ℃,the CaCO_3 and CaO mainly transformed to anhydrite and lime which didn't react with the mineral composition in coal slime.When the temperature was higher than 820 ℃,the CaCO_3 and CaO transformed to anhydrite and quick lime,and the quick lime reacted with silicon dioxide and aluminum oxide to form gehlenite. When the temperature was above1 000 ℃,some of sulfur retention products CaSO_4 began to break down,so the sulfur capture efficiency reduced. Compared with the briquette prepared using coal slime only,the addition of sulfur retention agents could improve sulfur capture efficiency obviously.
下载: