Study Of Fire Source Location Method Of Spontaneous Combustion Of Sulfide Ores Based On Surface Temperature Detection

Abstract:Spontaneous combustion of sulfide ores is one of the major hazards in safe mining of sulfurous ore deposits, and affecting the safety in mining for a long time. Spontaneous combustion of sulfide ores is a complex physical and chemical process including the oxidation of sulfide ores giving out heat, storing heat cause the temperature rise. The fire source of spontaneous combustion is elusive. So that research on the inner fire source location of sulfide ore spontaneous combustion 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 referring the relevant literatures and the former research results over the world, the research methods combining the theory of finite element analysis and numerical simulation, locating the inner fire source of sulfide ore spontaneous combustion based on the mathematical models. The inner fire resources position of ore pile under different conditions were analyzed, and the monitoring and prediction model of inner fire source location of sulfide ore pile were set up.The main research contents and results in this paper are as follows:(1) The current situation and specific application of inner fire source of sulfide ore spontaneous combustion prediction was introduced. The deficiency of infrared detection method is applied to locate the inner fire source of sulfide ore spontaneous combustion were described. Summarizing the development and application situation of the finite element numerical analysis method is applied to solve inverse problem of heat conduction for the source.(2)The mathematical models for describing the dynamic process of spontaneous combustion of sulfide minerals were deduced, including wind flow field and oxygen concentration field and temperature field. Combined with the inverse problem of heat conduction, the numerical simulation program of the inner fire source location of sulfide ore was determined. The inner fire source location of sulfide ore simulation was established by the ANSYS finite element method analysis system.(3) The finite element model of spontaneous inner fire source of sulfide ore in inversion was set up by using the ANSYS finite element method analysis system. Contour map of temperature distribution of each Sulfide ore point at a certain time, and the temperature of each node solution data were obtained by loading and solving the model. The location of the maximum temperature and the approximate area of high temperature fire area were obtained by temperature distribution coordinates.(4) Inner fire source location of sulfide ore pile under different conditions were analyzed through altering the temperature distribution on the surface of the ore pile, porosity, heat generation rate and thermal conductivity of ore sample. The temperature distribution situation on the surface of the ore pile has a great influence on inner fire source location of sulfide ore pile. If the arrangement of measuring points in surface temperature is different, the simulation results are quite different. When other conditions remain unchanged, the area of high temperature fire area of the ore pile increases with the increase of porosity, the area of high temperature fire area of the ore pile increases with the increase of heat generation rate, the area of high temperature fire area of the ore pile decreases with the increase of thermal conductivity.(5) Combined finite element analysis technology and temperature measurement technique based on the infrared thermal imaging, the monitoring and prediction model of inner fire source location of sulfide ore pile were established. The model includes the measurement of parameter values, the simulation of the inner fire source location of ore, prevention and control measures. Combine the technical measures and management measures to prevent and control the sulfide ore spontaneous combustion fire timely and effectively.