[en] Water accumulation in goaf is a great hidden danger to the coal mining safety, and detecting and removing the water accumulated in goaf has become a daily safety routine to ensure coal mining safety. This paper expounds the application of TSP technology in detecting the goaf water of Shuanglong coal mine, and it can be a valuable reference for the goaf water detection in the similar mines. (paper)

[en] A range of preventive works has been presented based on the example of one of the exploited longwalls and the costs borne by the coal mine have been exhibited. Further, the paper presents the costs of preventive aerological practices conducted for the improvement of work safety, borne by one of the coal mining companies. The paper also includes the calculation of cost indices. Based on these cost indices, an analysis of costs of the applied aerological preventive practices was conducted for the longwalls driven in years 2014-2015 by one of the coal mining companies. (paper)

[en] Southern Yakut coal basin is a huge and reliable base of the high-quality coked and steam coals in the east of the country. The Southern Yakut TPC was begun in the 70-s in the south of Yakutia forming, what predetermined considerable strengthening in this region of exploration works on coal. Now the fields of Neryungri, Elga and certain sites on Denisovsk and Chulmakan fields are developed by an open method. Absence near the operating Neryungri coal mine of the coalfields suitable for open-cast mining, and also finite useful lives of the Neryungri field (till 2018-2020) caused expansion of search works on coal on flanks of the basin, directed at identification of the powerful coal layers suitable for development by an open method. (paper)

[en] This article presents the general flow chart of stripping, mining, processing and handling of coal at Maamba Collieries. Major sources of environmental degradation starting from the Open Pit, Coal Preparation Plant(CCP), Aerial Ropewayup to the Screening Plantand dispatch facilities located some eleven kilometres away at Masuku Rail Terminalare pointed out. Past and on-going efforts by Maamba Collieries at ameliorating and, where feasible, mitigating of adverse environmental impact of mining, processing and handling of coal as well as limitations of these measures as applied at Maamba are presented and discussed. (author)

[en] Coal mining face is the place where coal mine accidents occur frequently.In this paper, the security early warning expert system is buliled based on the analysis method of system engineering and the investigation of coal mining face in a large number of coal mines. The classification, acquisition mechanism and representation of knowledge are described, and the system structure, reasoning mechanism and the establishment of knowledge base are also introduced. (paper)

[en] Due to the inability of the single line of sight D-InSAR to monitor the three-dimensional deformation of the surface, the conventional methods are unable to obtain the prediction parameters (probability integral parameters) of surface subsidence in coal mining. In this paper, a calculation method of simulated annealing (SA) for probability integral parameters based on single line of sight D-InSAR is proposed. Firstly, the method predicts the subsidence, the horizontal movement in the north–south direction and the horizontal movement in the east–west direction of the target pixel by using the probability integral method. Based on the projection relationship between the three-dimensional deformation and the LOS deformation, the predicted movement and deformation of the target pixel in LOS direction ($r_{i\text{LOS}}^{{}^{\prime }}$) are calculated. Using the measured movement and deformation of the target pixel in LOS direction ($r_{i\text{LOS}}$), the residuals of the target pixel are calculated ($v_i=r_{i\text{LOS}}-<!--\; ???\; -->r_{i\text{LOS}}^{{}^{\prime }}$) and the error function of the parameter is constructed ($\mathrm{\epsilon <!--\; ??\; -->}(B)=\sum <!--\; ???\; -->|v_i|$). Then based on the criteria ($\mathrm{\epsilon <!--\; ??\; -->}(B)=\text{min}$), all the probability integral parameters are obtained accurately by the SA method. The accuracy and robustness of the proposed method are verified by simulation experiments. At last, the predicted parameters of mining subsidence in 9310 working face of Nantun Coal Mine are calculated by this method, and the characteristics of probability integral parameters are analyzed.

[en] Coal mines in ecologically fragile areas in western China are seriously deficient in water. The contradiction between coal mining and water shortage is extremely sharp. Therefore, how to effectively protect and utilize water resources has always been an important problem that plagues western mining areas. Based on the analysis of the water environment characteristics of the western mining area, a coal mine waters circulation system is designed. It consists of ground sponge facilities and groundwater reservoirs in the coal mine goafs. (paper)

[en] Luling coal mine was used for research using FLAC^3D software to analyze the stress distribution characteristics of the two sides of a normal fault zone with two different working face models. The working faces were, respectively, on the hanging wall and the foot wall; the two directions of mining were directed to the fault. The stress distributions were different across the fault. The stress was concentrated and the influenced range of stress was gradually larger while the working face was located on the hanging wall. The fault zone played a negative effect to the stress transmission. Obviously, the fault prevented stress transmission, the stress concentrated on the fault zone and the hanging wall. In the second model, the stress on the two sides decreased at first, but then increased continuing to transmit to the hanging wall. The concentrated stress in the fault zone decreased and the stress transmission was obvious. Because of this, the result could be used to minimize roadway damage and lengthen the time available for coal mining by careful design of the roadway and working face. (paper)

[en] We would like to test the concept that induced seismicity prior to relatively large mining tremor (M_L > 2.5, E > 10⁶J) can be inferred from the cumulative Benioff strain release (BSR) as power law time-to-failure before the strong event. This study presents the application of accelerating BSR prior to a large earthquake, widely used in natural seismicity, for analysis of this phenomenon in induced seismicity. The Benioff strain release is quantified as accelerated releases of cumulative (square root sum) of seismic energy in the time series. During the study, five sequences were extracted from the seismic catalogues from two Polish hard coal mines: exhausted Bobrek Mine (data form the IS-EPOS Platform) and from a mine belonging to the Polish Mining Group. Next, a search radius was used to select precursory events and to indicate the type of processes occurring in the coal seam and its vicinity. The fitted power law of cumulative Benioff strain release showed changes of m-parameter. If the value of m was lower than 1.0, the process was regarded as an accelerating-like and if m was higher than 1.0—as a quiescence-like. The investigation of m-parameter vs. the search radius showed the general behaviour of the rock mass in the studied areas and allowed to evaluate the relationship between the critical radius and magnitude of the target event. The obtained scaling relation log(Rc) ~ 0.35 M_L is similar to these reported by other authors who analysed natural seismicity which might suggest that the scaling relation works in a wide range of magnitudes.

[en] In recent years, environment concerns have attracted a great deal of attention worldwide. It has been acknowledged that the danger of environmental degradation is threatening the very existence of mining industry. Simultaneously ecological awareness and sensitivity have spawned a new commitment, on part of the industry, towards the environment. Pertinent to note in this paper is that an economic model has also been developed, which describes the exploitation of Lignite and its interaction with rest of the economy, including the environmental consequences, to ensure that the damage caused to the environment and society is contained within acceptable limits. This model has been implemented as a workable and viable alternative for environment protection in a lignite mine in India. 5 refs