Study On Explosive's Self-Initiation Risk Assessment Technology And Its Application During Mining Of Sulfide Ores

Explosive's self-initiation is a class of major disasters during sulfide mining. Explosive's self-initiation accident has seriously affected the mines'safety and production. Therefore, study on explosive's self-initiation risk assessment during sulfide mining has practical significance in reducing corporate economic loss and ensuring production safety of the workers.Based on referring to many research fruits on mechanism and risk assessment methods of explosive's self-initiation, theoretical analysis, experimental measurement and numerical simulation were combinatively used to make a study on self-initiation mechanism, risk assessment methods and numerical simulation of stope temperature.The main research contents and achievements in the paper are as follows:(1) Based on the methodology of ISM, building sketch of Interpretative structural modeling of explosive's self-initiation during the mining of sulfide ore deposits was given. From the human-machine environment system analysis point of view,15 major factors which affected the explosive's self-initiation were selected, and then fact set system was built. By the inference and calculation of the adjacency matrix, multi-level hierarchical interpretative structure model can be obtained, and then interpretative structural modeling of explosive's self-initiation during the mining of sulfide ore deposits was constructed and analyzed according to the actual significance of each factor. Study shows that factors of explosive's self-initiation can be divided into 7 levels, and different levels of the factors and their associated impact are clear. The method provides a new idea and direction for the study on the mechanism of explosive's self-initiation during the mining of sulfide ore deposits.(2) Assessment indicator system of explosive's self-initiation risk during sulfide mining was established, in which evaluation indexes can be divided into quantitative indicators and qualitative indicators. Hazard classification was made, and according to the different risk levels, different range of quantitative indicators was given, while for qualitative indicators, the assignment method was used to quantify the qualitative indicators. Based on matter-element theory and the correlation function, extension theory was introduced to the assessment of explosive's self-initiation risk, and extension synthesis assessment model of explosive's self-initiation risk during sulfide mining was built. Two-level extension synthesis assessment method was used in one mine, and evaluation results was in line with the actual situation. The application shows that the method used in explosive's self-initiation risk assessment during sulfide mining is reasonable and feasible.(3) Based on explosive's self-initiation risk during sulfide mining, flowchart of experimental study was built. Laser particle size analyzer was used to measure an ore sample with different sizes, and then an experimental apparatus was designed, by determining the deflagration point, the influence degree of mineral particle size and moisture content on explosive's self-initiation was analyzed. The results show that for the same kind of ore, it's more dangerous for the mine-like with a smaller particle size when contacting with explosives, that is, a greater explosive's self-initiation risk; when the moisture content is about 5%, the self-initiation risk of explosives is larger than that of the water content of 0% and 10%. Through experimental study on three typical kinds of ore samples in a copper mine, research shows that there is the possibility of explosive's self-initiation, and the allowable temperature of safe charge is also gained. The results show that experimental study on explosive's self-initiation risk has an important role in guiding sulfide ore production safety.(4) The existing of high temperature stope is one important reason for explosive's self-initiation. Through the use of ANSYS on stope temperature, simulation results show that, whether it is charging or not, the temperature will rise over time, while charging, the heating rate is higher, and the temperature is also higher. The third day the main stope temperature was up to 44.821℃,6.821℃more than the initial temperature, and the maximum temperature may even get to 49.118℃. Compared with previous test results, the stope charge no more than 3 days is still relatively safe, but attention should be paid to taking appropriate safety measures.