硫化矿石自燃影响因素分析与实验研究

发布时间：2018-06-30 06:45

本文选题：硫化矿石 + 自燃　；参考：《重庆大学》2016年硕士论文

【摘要】：硫化矿石自然发火事故是金属矿山开采中的一项重大安全隐患。火灾的发生将造成许多的安全和环境方面的问题,恶化井下作业空间,污染地面空气,危及工人人身安全,并且会损失掉大量的矿石资源。矿石被开采后,矿石的表面会成倍的扩大,导致矿石易于接触周围的湿空气,也更易于出现氧化反应而产生一定的热。当生成热无法有效的向外界散失时,矿石的温度将会持续升高,一直升高到接近自燃点,最终引起自燃发生。因此,进一步研究分析硫化矿石自燃问题,弄清楚自燃火灾发生的原因机理、影响火灾发生的具体因素、相关的检测方法和监测措施以及预防火灾发生的具体手段措施,具有十分重要的现实意义。但是,由于硫化矿石自燃机理的复杂性,使得关于硫化矿石自燃的相关成果并不算丰富。因此,本文结合前人研究,在大量参阅相关文献的基础上,基于事故树的理论分析、实验室氧化指标的测试以及数值模拟软件计算等方法手段,展开了关于硫化矿石自燃倾向性的实验和理论研究,得到了如下研究成果:(1)对硫化矿石的发生机理进行了系统的分析与阐述,并介绍了硫化矿石的自燃倾向性鉴定和预防自燃的相关技术措施的研究情况。(2)在理论上采用事故树分析的方法研究了矿石自燃因素的特点。通过加入微生物机理中的相关影响因素,得到了该事故树的最小割集与最小径集,并对各影响因素的结构重要度进行分析,得出重要度靠前的X9氧化增重率大、X10矿石吸水性强、X11环境湿度大等因素在预防矿石自然发火事故时,要重点考虑与分析。(3)以新疆某铜矿为工程背景,进行了硫化矿石的实验室测试。采用实验室综合测试的实验手段,主要进行了以下检测内容:测试了硫化矿石的化学成分,进行了矿相分析,测试了自热点、自燃点和吸氧速度等指标。并对经过一段时间氧化的矿样测试分析。得到如下结果:阿舍勒铜矿矿石含硫量较高,平均含量为34.9%;矿石主要含有的金属矿物为黄铁矿、黄铜矿和闪锌矿,矿物构造简单,主要呈现为块状和碎裂状状态;矿样中Fe2+、Fe3+和SO42-的含量在氧化反应不断反应下,含量水平都不高;矿石在常温下氧化特性不高,经过预氧化后,氧化活性有小幅提高,矿石的自燃倾向性增强,但矿石在正常生产条件下没有自燃倾向性。(4)采用Fluent软件,在已建立的硫化矿石堆传热模型的基础上,对矿石堆模型进行改进,构建了三角形的矿石堆模型,并对矿石堆模型的气流场和温度场进行数值计算研究,得到了硫化矿石堆在不同的时间节点的气流场和温度场分布情况。算得了硫化矿石堆在初始状态、堆放5天和堆放10天时的温度场和气流场分布情况,以及在风流条件为0m/s、0.2m/s和0.4m/s的条件下矿石堆的温度特征。
[Abstract]:Spontaneous combustion of sulphide ore is a major safety hazard in metal mining. The fire will cause many safety and environmental problems, worsen the underground working space, pollute the air on the ground, endanger the personal safety of workers, and lose a lot of mineral resources. After the ore is mined, the surface of the ore will expand exponentially, resulting in the ore is easy to contact the wet air around it, and it is more prone to the oxidation reaction to produce certain heat. When the heat of formation can not be effectively dissipated to the outside world, the temperature of the ore will continue to rise until it is close to the spontaneous combustion point, which eventually leads to spontaneous combustion. Therefore, to further study and analyze the problem of spontaneous combustion of sulfide ore, to find out the cause mechanism of spontaneous combustion fire, the specific factors affecting fire occurrence, the relevant detection methods and monitoring measures, as well as the specific measures to prevent fire. It has very important practical significance. However, due to the complexity of the spontaneous combustion mechanism of sulphide ores, the related results on spontaneous combustion of sulphide ores are not rich. Therefore, based on the previous research, based on the theoretical analysis of accident tree, the test of laboratory oxidation index and the calculation of numerical simulation software, based on a large number of references, The experimental and theoretical research on the spontaneous combustion tendency of sulfide ores has been carried out. The following results have been obtained: (1) the mechanism of sulfide ores is systematically analyzed and expounded. This paper also introduces the research status of autoignition tendency identification of sulphide ores and related technical measures to prevent spontaneous combustion. (2) the characteristics of spontaneous combustion factors of ores are studied by accident tree analysis method in theory. The minimum cut set and the minimum path set of the accident tree are obtained by adding the relevant factors in the microbial mechanism, and the structural importance of each influencing factor is analyzed. It is concluded that the factors such as high weight gain rate of X9 oxidation and high water absorption and high environmental humidity of X10 ore should be considered and analyzed in order to prevent the spontaneous combustion accident of ore. (3) taking a copper mine in Xinjiang as the engineering background, Laboratory tests of sulphide ores were carried out. The main contents of this paper are as follows: the chemical composition of sulphide ore is tested, the mineral phase analysis is carried out, and the indexes of self-hot spot, spontaneous combustion point and oxygen absorption rate are tested. The ore samples that have been oxidized for a period of time are tested and analyzed. The results are as follows: the ore of Asherh copper deposit has a high sulfur content with an average content of 34.9.The ore mainly contains pyrite, chalcopyrite and sphalerite, and the mineral structure is simple, and the ore is mainly in a massive and fragmentary state, and the ore is mainly composed of pyrite, chalcopyrite and sphalerite. The contents of Fe _ 2, Fe _ 3 and so _ 4 ~ (2-) in ore samples are not high under continuous oxidation reaction, and the oxidation characteristics of ores are not high at room temperature. After preoxidation, the oxidation activity is slightly improved, and the spontaneous combustion tendency of ores is enhanced. But the ore does not have spontaneous combustion tendency under normal production conditions. (4) based on the established heat transfer model of sulphide ore reactor and fluent software, the ore heap model is improved, and the triangular ore heap model is constructed. The flow field and temperature field of the ore heap model are numerically calculated and the distribution of the gas flow field and the temperature field at different time nodes of the sulphide ore heap is obtained. The distribution of temperature field and flow field in the initial state, 5 days and 10 days of stacking of sulphide ore are calculated, and the temperature characteristics of the ore heap under the condition of 0 m / s / s 0.2 m / s and 0.4m/s are also calculated.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD752.2

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