Advanced Materials Research Vol. 868

Abstract: China is the world's important country in exporting rare earth, but in recent years, the development of rare earth industry has not sailing plainly. This paper uses game theory to analyse root causes behind the phenomena such as the "Cabbage Price" of rare earth have been sold; the vicious and brutal competitions in rare earth industry; declined profits of export corporates; the unsuccessful policy have been carried out of sustainable development of rational development and protection of resources and the environment and puts forward some appropriate policy recommendations respectively.

Abstract: Representative Elementary Volume (REV) is not only a necessary measure for studying heterogeneous pore structure of reservoir rocks but also an important parameter for core-scale numerical modeling. In this paper, we accordingly analyze the REV for different porous media with different grain sizes based on computed tomography (CT) measurement. Our results show that that CT measurement is a relible method for REV analysis and that there is an appropriate linear relationship between grain size and REV.

Abstract: In order to reduce operating temperature of deep mine, took shallow rock layer low temperature effect of mine as natural energy (cold) source in the spring and summer, used shallow abandoned waste roadway as cooling space to carry out research on deep cooling ventilation. Built model of heat and moisture exchange between inlet airflow and low temperature rock layer, carried out numerical simulation for inlet airflow cooling process of specific test mine. At the same time, inlet airflow cooling results of the experimental mine was gotten through testing and verifying. Results show: using this natural energy (cold)source that shallow rock layer low temperature effect of metal mine and abandoned resource of roadway, shaft, slop etc. cooling the inlet airflow instead of artificial refrigeration to auxiliary mine deep cooling in the spring and summer have practical saving energy significance and better applied prospect.

Abstract: The roof of 12501 transportation roadway of Tunlan mine is friable. To solve the problem of large roadway deformation, the bolt-mesh-anchor support scheme is put forward. With the FLAC3D numerical software in the program, the simulation analysis shows that the program can effectively increase the roadway confining pressure to improve the state of the surrounding rock stress, reduce roadway displacement and deformation and thus keep the stability of the surrounding rock. The results show that Bolt and cable support can effectively control the surrounding rock, with the roadway convergence rate small, and the support system safe.

Abstract: Since safety of roadway and steady of rock depend on bolt and cable supporting quality ^[~[, it is important to evaluate timely bolt and cable supporting quality that monitors tension state of bolt and cable. With separated type design, the monitoring instrument, which is to monitor tension of multiple survey point and separation type Bolt and Cable, is made up of tension of bolt and cable sensor and secondary measuring instrument. This paper focuses on the composition and the basic principle of the tension of bolt and cable sensor structure, the composition of secondary measuring instrument structure and functional partition of the chips and circuit theory of the monitoring instrument. This paper introduces the concrete implementation way and the conditions of usage of the monitoring instrument and introduces the monitor in the application of the auxiliary slot of 22301 working face of Shen Dong coal group Shi Ge Tai ore.

Abstract: The emission in atmosphere results in global climates warm, reduction of emission is growing concern of many countries. The geological storage of is effective method to reduce emission. Because coal seam has strong absorption capacity for ,the coal seam can be used as geological storage reservoirs, and coal seam has such characteristics that coal seam is preference for absorption and postponement for absorption, injection into coal seam can enhanced coal bed methane recovery, -ECBM, because and compete and absorb in coal seam , displace , hence coal bed methane can be obtained by The geological storage of in coal seam,is a energy generated by methane from injection into coal seam, injection into coal seam can not only reduce emission and but also enhance coal bed methane recovery, that is important to environment protection and energy sustainable development.

Abstract: Considering phosphate mine as an object, the text using Analytical Hierarchy Process established a model of cascade evaluation index system. And through the successful experiences of the cleaning production of advanced enterprises of phosphate mine at home and broad, this text determined the recommended value of evaluation index; And in this paper, using fuzzy mathematics method and the success experiences of experts, we put forward a quantitative evaluation method and established a cleaning production evaluation system of phosphate mine.

Abstract: Applying the method of source rocks pyrolysis to analyze 19 pieces of coal measure source rocks of Shanxi-Taiyuan group in Huanghua Depression, the results show that the level of organic matter abundance of coal measures hydrocarbon source rock in Shanxi-Taiyuan group of Well Wanggu 1 is the poor. Using monadic linear regression method to analysis the data of S₂ and T_OC, the results show that the type of the mudstone organic matter in the Shanxi - Taiyuan group belongs to III, the type of coal sample organic matter in Shanxi-Taiyuan group belongs to I. Due to the data of samples in the Shanxi group is less, the results of the coal sample in Shanxi group are only for reference. According to the data of Tmax, the most of the coal measures hydrocarbon source rocks in Shanxi - Taiyuan group are in the maturity stage, several samples are in the high maturity stage.

Abstract: In order to find the change rule of porous structure of oil shale during pyrolysis, the Huadian oil shale samples were heated to final temperature of 300°C400°C500°C600°C700°C. The pore structure and pore size distribution of oil shale and produced semi-cokes were measured by N2 isothermal adsorption/desorption method. The fractal characteristics and other parameters of porous structures were then analyzed in detail. The results indicate that the pores in oil shale were open at one direction while the pores in semi-cokes could be observed from two or even four directions. The pore sizes of semi-cokes were mostly between 3-5 nm; and the pore volume increased at a quickest rate when pyrolysis temperature increased from 400 to 600 °C. Oil shale and its semi-cokes all showed obvious fractal characteristics, whereas oil shale and the semi-coke from 600 °C gave the lowest fractal dimensions; this means that the matrix of oil shale tended to keep its original skeleton structure and the pore structure of semi-cokes from high temperatures became regular after devolatilization during the pyrolysis.

Abstract: Failure modes of jointed rock mass with different joint dip angle, joint center continuity degree, joint sets, load strain ratio and joint filling width under SHPB test are studied with model tests. The results show that failure modes and dynamic strength of jointed rock mass are much related to joint geometry. To rock mass with a single joint, its strength and failure mode are greatly controlled by the joint dip angle. The dynamic strength of the samples with joint dip angle 0° and 90°, whose failure modes are both tensile failure, is 90% and 71% of that of intact one, respectively. The dynamic strength of the samples with joint dip angle 60° is nearly zero. The dynamic strength of the samples with joint dip angle 30° and 45°, whose failure modes are mainly shear failure with partly tensile failure, is 50% and 18% of that of intact ones, respectively. The dynamic strength of the samples with 1/4, 1/2 and 4/5 joint center continuity degree is 95%, 74% and 28% of that of intact one, respectively. The dynamic strength of the samples with 1, 2 and 3 sets of joints is 54%, 23% and 10% of that of intact one, respectively. The dynamic strength of the intact and jointed samples both increases with load strain ratio, and the sensitivity to load strain ratio of the former is much higher than that of the latter, whose failure mode becomes more complicated accordingly. With increase of joint fillings width, the samples dynamic strength decreases gradually, but its failure mode does not change.