【作者】 阳富强；

【导师】 吴超；

【作者基本信息】 中南大学 ， 安全技术及工程， 2007， 硕士

【摘要】 我国矿山企业中,有许多硫化矿山,遍及有色、化工等系统,分布于全国各地。据不完全统计,其中20%～30%的硫铁矿及5%～10%的有色金属矿或多金属硫化矿都存在内因火灾的危险。硫化矿山内因火灾不仅恶化了井下的作业环境,污染地面空气,影响工人的身体健康,而且造成矿物资源的巨大浪费,还可能破坏井下设备,影响采矿作业的正常进行,甚至造成重大的人员伤亡事故。因此,对硫化矿山的内因火灾进行机理研究并及时预测预报就显得尤其重要。然而,硫化矿石堆的自燃过程是个极其复杂的氧化自热,从常温状态转变到燃烧状态的物理化学过程。本论文在查阅大量有关硫化矿石及煤炭自燃研究成果的基础上,就硫化矿石堆氧化自热机理、表面温度分布规律、自燃发火预测预报方法等方面做了大量的理论和实验研究,论文的主要研究内容和结论如下:(1)参阅了国内外关于硫化矿石氧化自燃及煤炭自燃的研究成果文献100余篇,包括煤炭自燃及硫化矿石堆自燃预测预报技术的研究现状,硫化矿石自燃火灾的综合防治措施等;系统阐述了硫化矿石堆的氧化自热机理。(2)利用硫化矿石堆内气体的流动状态和多孔介质动力学理论、传热传质学,并结合达西定律、连续性方程、质量守恒定律、能量守恒定律,推导出描述具有内热源的硫化矿石堆自燃发火充分必要条件的动态演变过程的数学模型,并以描述其自燃发火的数学模型为理论依据,建立了硫化矿石堆自燃预测的综合数学模型。(3)根据现场的边界条件,利用CFD软件FLUEN7对粉状硫精矿石堆及采场块状硫化矿石堆进行了二维网格划分,进而进行了硫化矿石堆内部风流场及温度场的数值模拟,从而更加直观地掌握硫化矿石堆内部温度在某一时刻的分布。(4)为了研究红外测温仪在不同感温距离、感温角度、不同环境、不同采场的硫化矿石堆参数等条件下,其感温读数与实际矿堆表面温度的关系,作者在实验室同时用Raytek红外测温仪与CENTER接触式测温仪测量了三种不同类型硫化矿样的表面温度,并对测量结果进行深入分析,得出了重要结论。(5)介绍了红外辐射的相关理论知识;以上述研究结论为指导,总结出了适用于预测预报硫化矿石堆自燃的红外检测装置的选择方法,并将其运用到现场当中,达到了较好的效果。(6)最后,从硫化矿石堆氧化自热数学模型的建立,数值模拟软件的开发,红外测溫技术的研究等方面对硫化矿石堆自燃的研究现状作出了一些展望,这对硫化矿山的安全生产具有重要的指导意义。更多还原

【Abstract】 Lots of sulfide ore mines exist among Chinese mining companies, spreading over nonferrous and chemical systems. It is estimated that 20% to 30% sulfide iron mines and 5% to 10% nonferrous or multi-metal mines have the hazard of spontaneous combustion. The fire caused by internal reasons in sulfide ore mines not only worsens the underground work environment, pollutes the ground air, affects the workers’ health, but also wastes a lot of resources, and destroys the equipment, influences the normal task seriously, furthermore, it leads to huge life losses. Therefore, it is of great significance to research over the oxidation mechanism of sulfide ores and to predict and forecast the spontaneous combustion for sulfide ore dumps in time.The spontaneous combustion of sulfide ores is an extremely complex physicochemical course, which often changes from the static state under normal temperature to dynamic state of combustion. Based on referring to many research fruits on spontaneous combustion of sulfide ores and coal, study both in theories and experiments were made in-depth, such as the mechanism of oxidantion and self-heating, the distributing law of surface temperature, predicting and forecasting methods, and so on. The main study contents and conclusions of this paper are as follows:(1) The research production on the oxidation and spontaneous combustion of sulfide ores and coal were summarized by reading about 100 references, including the status quo of predicting and forecasting technology, comprehensive preventing and fathering measures. Moreover, the mechanism of spontaneous combustion was set forth in details.(2) The theories on the flow pattern of the air inside sulfide ore piles and porous medium dynamics, heat and mass transfer, combining with Darcy Law, continuity equation, conservation of mass and energy, were used to deduce a mathematical model, which was sufficient to describe the dynamic process of sufficient and necessary conditions for spontaneous combustion of sulfide ore piles. Based on the mathematical model of spontaneous combustion, the comprehensive model for predicting spontaneous combustion was built.(3) Combining with the boundary conditions on the spot, the powder and block sulfide ore piles were plotted out grid in 2D, moreover, the airflow and temperature field were simulated by applying CFD software FLUENT. Therefore, the transformation of its inner temperature can be known at some time.(4) In order to research the connection between the sensing data of the infrared thermometer and the actual surface temperature for various measuring distances, ore samples, and environmental conditions, the surface temperature of three different sulfide ore samples were measured by Raytek infrared thermometer and CENTER tangent thermometer simultaneously, and the measured values were analyzed in details, some important conclusions were gained, too.(5) Some theories about infrared radiation were introduced; Based on the study conclusions above, the choice principles of infrared measuring instrument for predicting and forecasting spontaneous combustion of sulfide ore dumps were summarized. These were used in actual piles and took effect well.(6) At last, some prospects over the building of oxidation and self-heating mathematic model, the research of numerical simulation software, and the developing of infrared measuring instrument, were made, which are of great significance for sulfide ores production.更多还原