Advanced Materials Research Vols. 962-965

Abstract: Based on the analysis of network theory and the airflow abnormal value of mine ventilation, the concept of sensitivity was introduced and a mathematical model to analyze the reason for the airflow abnormal values so as to realize the analysis for the airflow in all kinds of tunnels of ventilation system was put forward. By doing that, various reasons for the airflow abnormal value could be found so that possible predictions for the safety consequences could be made accordingly.

Abstract: The experiment uses lime, desulfurization ash, slag and other solid wastes with mirabilite and NaOH as the admixture for Jinchuan mine rod milling sand to get a new backfill cementing materials that can replace the cement materials. There obtains the influence of activators to strength of the new backfill cementing materials’ body through the orthogonal experiment. The MATLAB genetic programming is exploited for getting the regression function of compressive strength and shrinkage rate for the new backfill cementing materials. Using the genetic algorithm to optimize the constrained regression functions that can get the best combinations of the activators, Finally. The results show that the compressive strengths (28d, 7d, 3d) of new backfill cementing materials are 6.73MPa, 4.03MPa and 1.00MPa when the lime, desulfurization ash, mirabilite, NaOH and slag are 7.05%, 16.32%, 3.062%, 1.08% and 72.48%. The optimal results conform to the requirements of the Jinchuan mine filling strength, which lays a foundation for further industrial test of new backfill cementing materials in Jinchuan mine.

Abstract: The typical high temperature environment of the mine, using single index evaluation system has been unable to meet the requirements of mine thermal environment of high temperature. Through the analysis of thermal equilibrium conditions affecting the thermal comfort of the mine workers of various factors and human thermal exchange model, that the decision to control the environment and human factors is the average temperature of the heat exchange of the skin. For high-temperature thermal defects existing mine environmental assessment indicators, the average temperature in the heat to the skin comfort zone as an index, the index system is established based on theoretical calculations WSBGT of mine thermal environment for effective assessment, provide the basis for mine cooling design.

Abstract: Based on definition of porosity, permeability model of gas-bearing coal was build which took porosity gas pressure, gas adsorption expansion, temperature and crustal stress into account, and the factors affecting the permeability of gas-bearing coal has been analyzed theoretically. The results show that permeability decreased exponentially with crustal stress increasing, permeability decreased linearly with temperature increasing and permeability decreased first and then increased with gas pressure increasing; crustal stress had the strongest effect than gas pressure and temperature, decreasing crustal stress was the most effective way to increase permeability and to improve extraction; the results verified by experiments data show that the smaller error and the higher prediction accuracy can meet production practical requirement, which could provide some guidance to gas extraction.

Abstract: The methane molecule model, the coal molecule model and the absorption model of coal and methane have been thoroughly investigated using the DFT method,Van der Walls force radius as boundary conditions as well. The investigations focuses on optimizing the three types of model structure. Meanwhile, adsorption equilibrium geometries with 6-311G++ basic sets have been established. Through the model analysis of the changes in the structure and Millikan charge from free state to the adsorption states, the results indicate that the adsorption process of methane gas on the coal in the Van der Walls force mainly dispersion forces and induction force, methane molecules are polarized in the adsorption process, the electric dipole moment.

Abstract: The “three volume” and the characteristics of deformation and damage of coal seam were observed and analyzed, the appropriate mine pressure control measures were proposed and put into production practice.

Abstract: The use of data from near misses in safety management has been identified as an important practice in the prevention of accidents. In this paper, the factors of impacting near misses reporting in China coal mine are investigated based on literature review and questionnaire survey. The influence effect sequence is: no number requirement, manager’s attitude to reporting , lack of feedback and follow-up, fear of social sanction, fear of punished, difficult to identify near misses, complicated reporting procedures, psychological factors. Work (setting formal goal for number of report, motivate miners to report, give feedback on report, development a no blame culture, training miners, etc.) has to be done continuously in order to get benefits from the near miss reporting system in coal mine.

Abstract: In the coal production, coal belt conveyor as an important device to play a very important role, once the belt is abnormal, it is bound to affect the entire coal mine production safety. Article summarized the application of daily maintenance of belt conveyor under cloud computing environment, and introduces several kinds of common problem solving methods, to optimize the coal mine enterprise safety and stability of the belt conveyor equipment.

Abstract: Xiongcun district is located in the western segment of the Gangdese porphyry copper belt, Tibet. Exploration activities in the No.I, No.II and No.III deposits in the past decade suggest that it would be a large prospective for porphyry copper-gold resources. In this paper, we focus on the systematical research of the elements spatial distribution of the No.II porphyry copper-gold deposit in the Xiongcun district. The results show, from center to the outer parts of the orebody, the elements distribution can be divided into Cu, Au, Ag, K, Mo and Ba → Co, Ni and Mn → Na and Ca → Pb, Zn, Cd, Bi, Sb and As. The No.II deposit is still open down-dip to the north and along the NW-striking, it need to conduct additional exploration.

Abstract: Abstract: The nouniformity of rock and soil materials and differences of boundary conditions caused the differentiation of stress field, together with the elastic-plastic characteristics of sliding zone material control the progressive unstable failure process. In this paper, The analysis of engineering example shows that the mechanical criterion is reasonable to judge the state of progressive slope evolution.