硫化矿自燃的机械活化机理

为了揭示硫化矿发生自燃的本质原因,从典型金属矿山采集了具有代表性的矿样,在室内开展了硫化矿的机械活化实验.采用扫描电镜(SEM)、X射线衍射技术(XRD)、综合热分析技术(STA)表征了矿样在经历不同时间的机械活化作用后的表观形貌、微观结构和热行为等物理化学性质的差异.结果发现:硫化矿石经历机械活化作用后,比表面积增大,出现团聚效应,产生晶格畸变与晶格缺陷,初始放热点及最大反应速率所对应的温度值均有所下降.由此提出了一种新的解释硫化矿自燃的机械活化理论,认为在金属矿山开采中施加于矿体上的各种机械力使得硫化矿产生了机械活化效应,从而使化学反应活性得到相应提高,在一定的环境条件下更加容易产生氧化自热,最终引发自燃火灾.

Mechanism of mechanical activation for spontaneous combustion of sulfide minerals

In order to uncover the intrinsic reasons for spontaneous combustion of sulfide minerals, representative samples were collected from typical metal mines to carry out the mechanical activation experiment. The structures and heat behaviors of activated samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and simultaneous thermal analysis (STA). It is found that the sulfide minerals after mechanical activation show many changes with increased specific surface areas, aggregation phenomenon, decreased diffraction peak intensity, broadened diffraction peak, declined initial temperatures of heat release and self-ignition points. A new theory for explaining the spontaneous combustion of sulfide minerals is put forward: the chemical reaction activity of sulfide minerals is heightened by all kinds of mechanical forces during the mining, and the spontaneous combustion takes place finally under proper environment.