Study on the characteristics of mineral matter in Huainan coals by computer controlled scanning electron microscope (CCSEM)

The mineral features, ash composition, ash fusion temperature of Huainan coals were investigated by CCSEM, X-ray fluorescence (XRF) and JIS (Japan Industrial Standard) ash cone melting method respectively. The mineral matter is characterized by higher aluminosilicate clay minerals contents (more than 60% of the total mineral matter in coal) with quartz, which accounts for the higher ash flow temperatures, frequently higher than1 500℃. The contents of calcite and dolomite in Huainan coals range from 0.16% to about 11.57%. Another important non-silicate mineral matter, pyrite, ranges from 0.73% to 12.25%. Low amount of kaolinite-type clays and high amount of calcite and pyrite in the HN115 and XM coals are beneficial to ash melting. It is suggested that the high content of kaolinite in Huainan coals shows the high ash fusion temperature. CCSEM results also provide the size distribution of the minerals in Huainan coals. Generally, the mineral has bimodal size distribution in 6 Huainan coals.

煤燃烧过程矿物质行为研究

In this paper, muffle furnace and 4 corners combustion furnace are chosen to heat andburn the coal ash and raw coal. The vartiation of components of mineral matters duringheating is analysised by XRD. It shows that the behavior of mineral matters in coal ash in 4corners combustion furnace is similar to that in muffle furnace, and the behavior is greatlyrelated to the compositions and amounts of raw coal.

碱性矿物质对煤灰熔融特性影响的研究

将K2 O和Na2 O添加剂按不同比例分别掺入两种煤灰中制成混合灰样 ,对混合灰样的熔融特性进行实验研究 ,采用X衍射图谱得到混合灰样不同温度的矿物组成 ,并利用三元系统相图进行分析 .结果表明 ,在还原性气氛下 ,混合灰样灰熔点特性曲线与K2 O Al2 O3 SiO2 和Na2 O Al2 O3 SiO2 三元系统相图液相线温度曲线相似 ;

煤中矿物质对灰熔融温度影响的三元相图分析

采用ＣａＯ和Ｆｅ２Ｏ３添加剂按不同比例掺入煤灰中制成混合灰样，对混合灰样的熔融特性及其矿物组成进行试验研究，并利用三元系统相图进行分析．结果表明，在还原性气氛下，混合灰样与ＣａＯ－Ａｌ２Ｏ３－ＳｉＯ２和ＦｅＯ－Ａｌ２Ｏ３－ＳｉＯ２三元系统相图具有相似的熔融特性温度曲线；

添加秸秆类生物质对长平煤灰熔融特性的影响

借助高温热台显微镜、扫描电子显微镜-能谱仪、灰熔点仪和X射线衍射仪考察了添加稻草和棉秆两种秸秆对长平煤灰熔融特性的影响。研究结果表明添加两种秸秆都能有效地降低长平煤灰的熔融温度。在高温弱还原性气氛下,长平煤灰主要矿物组成为耐熔性石英和莫来石,而添加秸秆后产生了白榴石、尖晶橄榄石、钙长石等低温共熔化合物,使长平煤灰熔点降低。不同灰的高温熔融图像表明,煤灰在熔融过程中由于受热而使固相持续软化,形成了不利于难熔物分解的高黏度熔体。而煤和稻草的混合灰在熔融时形成了易发生流动的低黏度熔体,能够促进矿物质发生反应而更易熔融。