空气中煤低温加热性质变化

The effect of low-temperature heating on coal characters in air atmosphere

采用热重仪和电动直剪实验仪考察 6种煤在空气中低温 (<5 0 0℃ )加热对其性质影响 .研究表明 ,6种煤在空气中受热后都先经历一个不同程度的增重过程 ,然后再随温度升高失重 ;煤粒越细 ,增重量越大 ;随升温速率的提高 ,热重TG曲线向高温移动 ;空气流量对煤低温失重没有影响 ;煤粒受热后其流动性质发生变化 ,即其内摩擦角和壁摩擦角都减小 ;X粉晶衍射图表明 ,煤中矿物质被氧气氧化生成硫酸盐是煤在空气流中受热增重的主要原因 .

The effect of low-temperature heating on coal characters was studied by means of termogravimetric analysis in air. The heating temperature was in the range of 120～500 ℃. The result showed that the coals′ weight gained before they began to loss weight in air, minerals of raw coals were the important reason for coals′ gaining weight; with the heating rate′s and coal particle size′s decreasing,coals lost more weight after they gained more weight; the air flow speed had not effect on coal TG curves, the wall friction angles and inside friction angles decreased when coals was heated and then cooled.X powder diffraction 6 graphs indicate that the sulphate oxidated from mineral in coal is the main reason in gaining weight of coal in air.