【作者】 刘辉；

【导师】 吴超；

【作者基本信息】 中南大学 ， 安全技术及工程， 2010， 博士

【摘要】 硫化矿石自燃是长期以来影响矿山安全生产的问题,已成为硫化矿床开采经常遇到的重大灾害之一。迄今,国内外学者对硫化矿石的自燃机理、自燃倾向性、预防以及控制方法等方面进行了大量研究,但由于硫化矿石自燃过程的复杂性和自燃火源的隐蔽性,使问题未能得到根本解决。‘随着我国矿产资源不断向深部开发的影响,深部开采面临的高温问题越发加剧了高硫矿石开采过程中自燃事故的频发,矿石自燃问题比以前显得更加突出。因此,研究硫化矿石自燃特性及其火源探测技术,对于深入了解井下矿石自燃过程,判定矿石堆燃烧状况和推断火源位置以及高效、快速地展开防灭火具有重大的理论意义和应用价值。论文在广泛查阅国内外相关文献和系统总结前人研究成果的基础上,采用理论研究、实验室模拟、数值分析和现场实验相结合的研究方法,对硫化矿石自燃的基础理论、矿石堆的聚热特性与自燃早期的发火规律、自燃矿石火源的红外热像探测方法及内火源定位技术等展开了系统深入的研究。论文的主要工作和获得的成果总结如下：(1)在已有的研究成果基础上,对典型硫化矿物的基础特性及硫化矿石自燃机理等方面相关研究的成果进行了综合分析、比较和总结,并就矿石与氧气复合作用生热的过程进行了系统探讨和分析,为探索硫化矿石自燃发火机理提供必要、可靠的理论基础和科学依据,把硫化矿石自燃发火的研究成果融汇成较完善、系统的基础理论体系。(2)揭示了氧气在硫化矿石堆内的流动方式主要为渗流流动和扩散流动；把矿堆堆体导热视为固体颗粒导热和矿堆内间隙气体的导热过程,并在此基础上推导了硫化矿石堆热量的积聚过程和聚热升温条件；采用理论和实验相结合的手段对硫化矿石堆热量积聚的影响因素进行了系统的研究,表明温度、空隙率、漏风强度、堆积体积、氧气浓度以及含水量和矿石粒度等是影响矿石升温的主要因素。(3)运用现代测试和分析技术对硫化矿矿样做TG/DSC分析,水溶液含量测定及电镜扫描等实验发现：①矿石升温过程有大量的热量释放；②氧化前后,矿样表面变得疏松多孔,呈疏松、破碎状,并伴有结块现象。③矿样中水溶性Fe2++Fe3+和SO42-离子的含量均有增加,特别是硫酸根SO42-含量,部分矿样增加幅度很大。研究表明这些现象为矿石氧化自燃过程的主要特征。(4)利用现场堆矿实验筛选了温度作为表征矿石自燃早期的最佳指标,并分析探讨了矿石堆内部的升温特性及其对矿堆表面温度的影响,获取了两者之间的关系,表明矿堆表面温度的变化,间接反映了硫化矿石氧化的本质和程度,且温度的变化在量的关系上与各阶段紧密相关,可以通过探测矿堆表面的温度变化来监测矿堆内部的自热、自燃情况,适宜作为早期监测矿石自燃的指标。(5)提出了用于探测硫化矿石堆自燃火源的红外热像方法。分析了红外测温仪的选择方法及矿用热像仪的选型；结合IRI-1011通用型热像仪对影响矿石自燃红外探测的因素进行了深入探讨,并提出了相应的校正措施。利用理论推导和数值模拟计算表明,现有的热像仪对于探测矿石堆10m内的火源均具有可行性；设计了探测工艺,获取了几组适应于IRI-1011型热像仪的探测距离与探测面积可选参数,并提出了大测面逐层划大为小的火源探测方法；在研究热传导反问题的基础上,探讨了自燃矿石火源的定位方法,并基于热像仪大面积扫描感温,提出了一种新的火源定位方法。更多还原

【Abstract】 Spontaneous combustion of sulfide ores is always affecting the safety in mining for a long time, and has become one of the major hazards in safe mining of sulfurous ore deposits. Nowdays, the sulfide ores spontaneous combustion mechanism, spontaneous ignition tendency, prevention and control methods were carefully analyzed by many scholars over the world. However, the problem was not solved ultimately because of the complexities of sulfide ores self-igniting process and the elusive of fire source of spontaneous combustion.With the rapid development of underground mine toward the depth, the high temperature of deeply mining is gradually aggravating the spontaneous combustion accident in mining process, and the ores self-ignition problem is more significant than before.So that research on the characterization of sulfide ores and the detecting technology of its fire sources have significant and realistic significance and applied value for us to understand the self-igniting process, estimate the present situation of ore piles, deduce the fire resources position and carry out the prevention action.On the basis of reviewing the previous papers in and aboard, the research methods combining the theoretical research, laboratory simulation, numerical analysis and field application were used to systematically and deeply analyze the fundamental theory, the heat-concentration ability of ore piles, the early stage fire law, the infrared detection methods of self-ignition resources, and the positioning technique of inner sources of ignition. The main work and achievements of the thesis are as follows:(1) On the basis of research findings, the fundamental natures of sulfide minerals and the ore self-ignite mechanism were synthetically analyzed, compared, summarized. And the interactive process of ores and oxygen was carefully discussed to provide dependable theoretical foundation and scientific proof for explore the sulfide ores self-ignition mechanism to perfect the sulfide ores self-ignition research achievements.(2) Seepage flow and diffusion flow were revealed to be major flow patterns of oxygen inside sulfide ore dumps. The thermal conductivity process of solid particles and clearance gas was considered as the thermal conductivity of sulfide ore dumps. Based on this, heat build-up process and poly-thermal heating conditions of sulfide ore dumps was derived; and then a systematic study on heat heap factors of sulfide ores was carried out using the combination of theoretical and experimental methods. It indicated that the main factors affecting ore self-heating were temperature, porosity, air leakage intensity, accumulated volume, oxygen concentration, water content and mineral particle size.(3) The modern testing and analytical techniques, such as TG/DSC analysis, solution content determination and Scanning Electron Microscopy were used for doing mineral samples, and the results were found that:①The process of mineral heating release a large amount of heat;②Before and after oxidation, mineral samples surface becomes porous, loose, broken, accompanied by agglomeration.③In the ore, the content of some ions which are water-solubility Fe2++Fe3+ and SO42- were increased, especially the content of SO42-, and some ore increased tremendously. Studies have shown that the phenomena are the main features of the ore spontaneous combustion oxidation process.(4) Using the in-site experimental reactor as the best indicators of ore spontaneous combustion in the early stage, and discussed the characteristics of the temperature in the internal heap of ore and the impact on the surface temperature, the relationship between them was got,that indicted that the change of the surface temperature indirectly reflect the nature and extent of the oxidation of sulfide ores, and the change of temperature was closely quantify connected with every stage, through monitoring the change of surface temperature,the self-heating, spontaneous combustion within the ore heap was detected, and was suitable to be the indicator of ore spontaneous combustion in the early stage.(5) It was proposed that the methods of infrared thermography for detecting spontaneous fire of sulfide ores. The selection methods of infrared thermometer and mining thermal imager were analyzed, the factors that influence infrared detection of spontaneous fire of sulfide ores were studied using the IRI-1011 general-purpose thermal imager and put forward the corresponding corrective measures. The theoretical derivation and numerical simulation show that the existing thermal imager detecting of ore pile fire source within 10m is feasible. The detection process was designed, and several groups of optional parameters for the detection range and detection area adapted to IRI-1011 thermal imager were obtained. Also, it is proposed a fire detection method of dividing the large detection area into small ones layer by layer. Based on the study of the inverse problem of heat conduction, the method of spontaneous fire source location was discussed, and it is proposed a new fire source location method based on thermal imager with a large area scanning.更多还原