硫化矿石自燃倾向性评价的非线性多参数融合技术及自燃预警研究

According to the results of laboratory experiments, the advantages and disadvantages of determination methods of spontaneous combustion tendency and the reliabilities of determination results for sulfide ores will be evaluated systematically. Furthermore, a set of universal indicators for spontaneous combustion tendency determination will be selected and their specifications will be established. A new evaluation method for spontaneous combustion tendency will be established by extracting, selecting and integrating the nonlinear parameters of related indexes series based on wavelet technology and nonlinear dynamics theory. The unsteady self-heating process of sulfide ore heap will be simulated in combination with laboratory experiment and field test. The temperature variation trend, the combustible region and the index gases variation laws will be explored and then the recognition technology for spontaneous combustion precursor can be proposed. The chaotic characteristics of self-heating process will be revealed and the temperature prediction model will be established by using the chaotic dynamics theory. The flow laws of air in meso-pore of the ore heap and the formation mechanism of combustible region will be studied based on the digital image processing and finite element technology. The distribution laws of air-flowing field, concentration field of SO2 and O2, and temperature field of the ore heap will be studied through the application of the theories such as porous media, heat and mass transfer, fluid mechanics and so on. The starting time of spontaneous combustion and the variation trend of spontaneous combustion region will be detected. The laws that the ore heap size, ore heap shape and environmental factors affect spontaneous combustion will be revealed. It can provide theoretical support for mines to prevent spontaneous combustion of sulfide ores through the study of the project.

结合室内实验，系统评价现有硫化矿石自燃倾向性测定方法的优劣及测定结果的可靠性，优选出一套自燃倾向性测定的普适指标并建立其测定规范；应用小波技术和非线性动力学理论对相关指标序列进行非线性参数提取、选择和融合，建立自燃倾向性评价的新方法；采用室内和现场相结合的手段模拟硫化矿石堆非稳态自热过程，探明矿石堆温度变化趋势、易燃区域范围和指标气体变化规律，提出自燃前兆识别技术；应用混沌动力学理论，揭示自热过程的混沌动力学特征，构建矿石堆自热升温预测模型；基于数字图像处理和有限元技术，研究矿石堆细观孔隙内空气的流动规律，探明易燃区域的形成机制；应用多孔介质、传热传质和流体力学等理论，研究矿石堆风流场、SO2和O2浓度场以及温度场的分布规律，预测自燃起始时间，揭示自燃区域的变化趋势以及矿石堆规模、堆形、环境因素对矿石堆自燃的影响规律。通过本项目的研究，为矿山防治硫化矿石自燃火灾提供理论支撑。

硫化矿石自燃火灾会诱发一系列的安全与环境问题，给矿山企业带来巨大的经济损失。本项目采取理论分析、实验研究、数值模拟相结合的研究手段，对硫化矿石自燃倾向性评价的非线性多参数融合技术及自燃预警进行了研究。主要研究内容和取得的研究成果总结如下：.(1) 开展了不同实验条件下的硫化矿石氧化、自热及自燃测定实验，优选出氧化增重率、自热点及自燃点作为自燃倾向性测定指标，对测定过程中的关键技术参数进行了系统研究，规范了相应的测定方案。.(2) 集成小波技术、非线性特征参数提取及模糊综合评判等方法，将表征矿石自燃倾向性的非线性特征参数进行融合，提出了基于非线性多参数融合的硫化矿石自燃倾向性评价方法。.(3) 采用室内三维探索性实验和现场试验相结合的研究手段，揭示了矿石堆温度与时间的关系、矿石堆不同区域对诱导自热过程的响应差异，重构得到模拟矿石堆的温度场，确定了自热层的范围，探明了自热过程中O2和SO2指标气体浓度的变化规律。.(4) 研究了硫化矿石自热过程的混沌特征，提出了将实测矿石堆温度序列拆分为趋势项、混沌项和随机项的概念，据此建立了矿石堆自热升温的趋势—混沌组合预测模型。预测结果表明，建立的趋势—混沌组合预测模型具有很高的预测精度，能够很好地适用于硫化矿石堆自燃早期预测。.(5) 采用数字图像处理和有限元技术相结合的方法，进行了矿石堆孔隙内空气渗流的数值仿真研究，揭示了矿石堆易燃区域的形成机制。开展了多场耦合数值仿真研究，揭示了采场中风流场、SO2 与O2 浓度场以及矿石堆温度场的分布规律，探明了矿石堆截面积、空气流速以及矿石堆高度对自热过程的影响规律。