In the process of TBM tunneling in coal mine roadway, tunneling parameters have a significant impact on propulsion efficiency, energy consumption and tool wear, and there is a complex nonlinear coupling relationship among them. Traditional empirical parameter tuning or single-objective optimization methods are difficult to balance efficiency, cost and safety. Therefore, this paper proposes a multi-objective optimization method for TBM tunneling parameters based on intelligent integration algorithm, which integrates Grey Wolf Optimization (GWO), Radial Basis Function (RBF) neural network, Non-dominated Sorting Genetic Algorithm (NSGA-Ⅱ) and TOPSIS decision method. The nonlinear mapping relationship between tunneling parameters and propulsion speed, tunneling specific energy and tool wear is constructed by RBF neural network, and GWO algorithm is used to optimize its hyperparameters to improve the prediction accuracy. On this basis, NSGA-Ⅱ is used to achieve multi-objective optimization, and the Pareto optimal solution set is obtained. Finally, the optimal solution is screened by TOPSIS-entropy weight method. Based on the measured data of TBM tunneling process in Zhengtong Coal Industry, the verification is carried out. The results show that the propulsion speed is increased by 23.97 % under the optimal scheme. The specific energy of excavation decreased by 26.44 %; the tool wear is reduced by 43.67 %. The verification results show that the method can significantly reduce energy consumption and tool loss while improving tunneling efficiency, and realize the collaborative optimization of efficiency, cost and safety, which has good engineering applicability and promotion value.

To address the deep-level coordination challenges across multi-vendor and cross-generational systems during the construction of Lijiahao Coal Mine's smart mine platform, the proposed collaborative control system adopts a hierarchical control architecture. A hierarchical collaborative control system is proposed, featuring three core layers: 1) A communication interface layer with an OPC UA-based protocol conversion gateway enabling compatibility among RS485, industrial Ethernet, LoRa, and other protocols; 2) A data fusion layer employing reinforcement learning algorithms for spatiotemporal alignment of multi-source data, facilitating the construction of a mine digital twin; 3) An intelligent coordination layer incorporating an event-driven dynamic coupling algorithm and a decision matrix integrating 32 state parameters. Application testing at Lijiahao Coal Mine demonstrated significant improvements: emergency response time reduced to 9.7 seconds and comprehensive equipment energy efficiency enhanced by 19.3%. By constructing a unified communication protocol stack and data fusion mechanism, and establishing a dynamic coupling model across systems, intelligent collaborative management and control of the mine production system has been achieved.

The application of BIM technology in the coal field is now mostly concentrated in the design stage of the ground coal preparation plant. On the basis of completing the BIM design of the coal project, this paper has carried out the research on the integration application of BIM technology and the new generation information technology, and combined with the needs of specific projects, proposed technology integration application methods such as "BIM+Internet", "BIM+GIS" and "BIM+IoT". In the Zaokuang Lianchuang Coal Storage and Blending Base project, the project site selection and land boundary, as well as the layout of buildings (structures) within the industrial site, were optimized through "BIM+GIS"; In the design project of Taohe Coal Mine, a three-dimensional mining system was constructed above and below the mine, achieving integrated display of ground terrain, industrial sites, and tunnel engineering. During the general contracting of the storage and transportation system project of Inner Mongolia Great Wall Minmetals during the COVID-19, an online 3D design disclosure and communication platform was built through "BIM+Internet", which realized efficient communication among all parties involved during the epidemic and ensured the smooth implementation of the project. In the general contracting of the cooling system project at Guotun Coal Mine, the integration of "BIM+IoT" technology enables real-time display of equipment operation data in a lightweight BIM model, realizing the extension of BIM technology in the field of engineering operation and maintenance.

Against the backdrop of the "Dual Carbon" goals and energy transition, the coal industry is accelerating its transformation toward green, intelligent, and efficient development. Taking Qianjiaying Coal Preparation Plant of Kailuan Group as a research example, this paper systematically explores the modernization path of large coking coal preparation plants from the dimension of engineering design. Aiming at the pain points of the original plant, such as outdated processes and lagging efficiency, core technologies including intelligent dry separation, pressureless three-product heavy-medium cyclone separation, deep coal slime flotation, high-efficiency solid-liquid separation, and high-precision online detection are applied to construct an integrated process system of "intelligent perception-precise separation-efficient recovery". Meanwhile, an intelligent management and control platform is established, integrating 5G, big data, and artificial intelligence technologies to achieve full-process automatic control of production and real-time monitoring and analysis of data.In terms of green development, energy consumption is reduced by optimizing transportation and storage systems, and facilities for dust removal and purification, washing water recycling, and comprehensive solid waste utilization are deployed to integrate green and safety concepts throughout the construction and operation processes. This practice has achieved dual breakthroughs in economic and ecological benefits, providing replicable practical experience for the coordinated development of the coal industry and the ecological environment, and indicating the direction for the transformation and upgrading of similar coal preparation plants.

A method was proposed using crumb rubber concrete instead of ordinary concrete materials for the construction of reinforced concrete silos, which are prone to cracking and impact damage in engineering. The influence of different reinforcement modeling methods on the accuracy of nonlinear numerical simulation of reinforced concrete structures was compared by introducing a steel double line constitutive model and a concrete damage plasticity model. A simplified rebar model embedded in concrete solid elements was selected to establish finite element models of sprayed concrete on air-form silo and reinforced concrete silo structures. The influence of crumb rubber concrete with different rubber contents on the static performance of silo structures was analyzed.

Regarding the problems of high maintenance cost, long construction period, and high safety risk of reused roadways under the "U+U" ventilation mode in high-gas mine mining faces, taking the mining of No. 3 coal seam in Wangpo Coal Industry as the engineering background, this paper systematically analyzes the deformation mechanism and control principles of reused roadways, and proposes a new layout scheme for special gas control roadways. Through the theoretical calculation of Wilson's nuclear zone stability and FLAC3D numerical simulation, the rationality of a 15m coal pillar is demonstrated, and a trinity surrounding rock control technology of "active support-cutting pressure relief-dynamic adjustment" is proposed. Industrial tests show that driving special gas control roadways can effectively avoid the adverse effects of reused roadway maintenance, and has obvious advantages in construction period, safety guarantee, economic efficiency, etc. The research results establish a collaborative optimization theory of "roadway function-coal pillar width-support parameters" for high-gas mines, providing new ideas for safe and efficient mining in similar mines.

Tunnel driving is a critical process in coal mine production. To address issues such as prolonged gas extraction time, slow cutting speed, and extended support operation duration in gassy and outburst-prone mines, this study proposes a new intelligent control technology for underground coal mine driving. The technology centers around a roadway boring and anchoring machine, integrating advanced gas pre-drainage, optimized support parameters, and interlocking control between gas concentration and cutting parameters. This approach significantly enhances both the efficiency and safety of tunnel driving. Practical application demonstrates that using directional long-hole drilling for gas pre-drainage reduces gas content at the driving face by 46.39%. By optimizing the roof support method and parameters according to the surrounding rock conditions, support density is reduced by 21.77% and support costs are lowered by 2.23%. Additionally, rational optimization of the collaborative workflow among supporting procedures increases cyclic driving efficiency by 33%. An interlocking control system between gas emission and the boring and anchoring machine has been established, achieving optimal matching of gas emission volume with the machine’s cutting speed. As a result, the monthly driving advance has more than doubled, while operational safety has been greatly improved. These outcomes achieve the goal of safe, efficient, and intelligent tunnel driving.

Based on on-site measurements, the general characteristics of deformation and soil nail stress in the foundation pit of a deep trench warehouse were obtained to address the stability issues of soil nail support beyond current standards. The results indicate that due to the thick layer of fine sand on the upper part of the foundation pit, the horizontal displacement of some measuring points at the top of the slope exceeded the allowable excavation depth limit of 3‰ according to the specifications. The axial force of soil nails increases continuously with the excavation of the foundation pit. Along the length direction of the soil nails, the maximum axial force of the upper soil nails generally occurs in the middle, while the maximum axial force of the lower soil nails often occurs in the middle and deep parts. Some soil nail axial forces even exceed 25% of the sensor range, and the upper filling will further increase the sliding range of the slope. Based on this, an optimization design concept for soil nail support is proposed without increasing the total length of soil nails. By appropriately increasing the horizontal spacing between upper soil nails and decreasing the horizontal spacing between lower soil nails, the support performance of upper soil nails can be fully utilized, the support area of a single soil nail in the lower part can be reduced, and the safety of the entire slope can be improved.

Abstract: In the mining process of double-entry layout working faces, roadway surrounding rocks are significantly affected by repeated mining disturbances, leading to severe ground pressure manifestations. To address this issue, the 226up03 return airway at Huangyuchuan Coal Mine was selected as the research object. Field measurements, numerical simulations, and theoretical analysis were employed to investigate the stress evolution characteristics of roadways under repeated mining disturbances, the failure mechanisms of surrounding rocks, and the formation mechanism of floor heave. Control strategies for mitigating floor heave were also proposed. The results indicate: ① Field measurements of surrounding rock deformation reveal that the influence of primary mining on roadway disturbance is limited in scope. During the initial mining phase, the roadway remains stable overall, with no significant deformation or failure observed. However, secondary mining exhibits phased strong disturbances, causing severe deformation of the roof and floor within a 40 m advanced range, with the affected zone extending up to 120 m ahead of the working face. ② The evolution of plastic zones in surrounding rocks under repeated mining was clarified: After roadway excavation and stabilization, rock failure is primarily concentrated in the floor. Minor disturbances occur during primary mining, while secondary mining intensifies the expansion of plastic zones in the floor, resulting in asymmetric failure patterns dominated by an inverted "7" shape. ③ The failure mechanism of floor heave under repeated mining was elucidated: The deflection angle of principal stress controls the expansion direction of plastic zones, the magnitude of maximum principal stress determines the failure range, and the presence of weak floor strata exacerbates stress redistribution, ultimately inducing floor heave. ④ Floor heave control strategies were proposed and implemented: By installing 7 m advanced supports ahead of the working face and reducing the spacing between each unit support by 400 mm, field tests demonstrated enhanced coordination between the floor and supports, improved surrounding rock stability, and ensured safe coal recovery in the working face.

In the application process of in-situ blocking technology, in order to clarify the infiltration law of blocking liquid inside coal under different injection conditions and improve the application effect of in-situ blocking technology, this paper takes the B2 coal seam of Guoneng Xinjiang Kuangou Mining Co., Ltd. as the research object, and determines the optimal composite long-acting blocking liquid ratio with the best wetting performance through reverse spontaneous imbibition experiments; Then, based on the optimized ratio of the blocking fluid and relying on the three-axis coal seepage system, the effects of different axial pressures, confining pressures, injection pressures, and blocking fluid temperatures on the wetting law of the blocking fluid in the coal were tested; Finally, a gas coal water body movement monitoring experiment based on acoustic emission array was conducted to clarify the variation law of the infiltration velocity of the blocking fluid in coal under different injection conditions, determine the relevant injection parameters of the blocking fluid, and apply the in-situ blocking process for fire prevention and extinguishing in the I010206 working face of Kuangou Coal Mine. Research has found that the optimal ratio of the blocking liquid has been determined through reverse spontaneous imbibition experiments. Under this ratio, the height of the reverse spontaneous imbibition experiment can reach 16cm after one day, and the wetting effect is excellent; The triaxial coal permeability test experiment shows that increasing axial pressure, injection pressure, and injection temperature can increase permeability, while increasing confining pressure can lead to a decrease in permeability; The monitoring experiment of gas coal water transport based on acoustic emission array shows that the injection pressure and injection temperature are positively correlated with the infiltration rate; After in-situ blocking, the residual coal falls into the goaf and is monitored by a bundle tube monitoring system, resulting in a significant decrease in CO concentration and good blocking effect. This study has a positive promoting effect on clarifying the flow range of blocking fluid under complex injection conditions and the development of in-situ blocking technology.

Aiming at the serious deformation of the wall of the gob-retaining lane along the roof of the composite key layer of the protruding coal seam, the difficulty in support, and the large amount of gas leakage in the gob, the theoretical modeling and mechanical analysis were used to study the effective pressure relief and stress transfer when the segmented fracturing fracture line was located outside the wall of the gob in the 20107 working face of the Qincheng Coal Mine in Shanxi Province. The analytical solution of the horizontal distance of the starting point of the segmented fracturing was given, and the positions of the middle and low bearing key layers were determined by combining the key layer theoretical analysis. The horizontal distance of the starting point of the segmented fracturing was determined to be 8.6m, and the vertical fracturing interval was determined to be 6.1-21.8m (low position) and 24.1-42m (middle position) from the roof. At the same time, it was pointed out that the triangular area between the fault line and the natural collapse line of the overburden is the gas enrichment area of the gob, and then the drilling layer of the gas extraction in the fracture zone was optimized to be 32-50m. The non-permeability fracturing theory and field tests of geostress were used to obtain the initiation and expansion pressures of staged fracturing of 26 and 20 MPa, respectively. The fracturing time was then determined to be 20 minutes and the flow rate was 22 m3/h, which ultimately formed an integrated technology of staged fracturing, cutting and protecting the roadway and gas extraction in the composite key layer of the high-burst mine. The field engineering test verified that the horizontal and vertical deformations of the optimized roadway wall were reduced by 1.41 and 1.82 times respectively compared with the original ones, and the gas extraction volume of a single hole in the directional drilling site increased by 0.72 times, and the total volume of each group was increased to 7.46 m3/min, achieving the coordinated governance of the deformation and instability of the roadway wall and the gas in the goaf.

The radius of coalbed methane extraction is influenced by multiple factors, It is difficult to determine the effective extraction radius, This article uses theoretical analysis and underground measurement methods to analyze the attenuation characteristics of drilling flow rate and derive the maximum extraction time of drilling,When the coal seam gas extraction rate is ≥30%, the calculation formula for drilling extraction radius is obtained, which provides a basis for the design of pre extraction drilling holes in this coal seam,The main conclusions are as follows: 1) The negative exponential relationship between drilling gas extraction flow rate and time is as follows: q1=0.081e-0.028t，q2=0.102e-0.033t，q3=0.093e-0.038t, The attenuation coefficient of drilling gas flow is 0.028～0.038d-1,The maximum extraction time for drilling is 78.9～107.1d, and the coal seam has moderate permeability. 2) When the extraction time is 120d, the calculated extraction radius is 2.26～2.45m,The pre pumping time measured by the pressure drop method is 115d, and the pumping radius is 2.25m. 3) When the extraction radius is 2.25m and the extraction time is 120d, the maximum value of residual gas content after pre extraction is 4.96 m3/t, which meets the requirements of the extraction design, The gas pressure decreased by 53.85～83.33%, and the extraction rate was 34.22～60.61%, and the desorption gas content after pre extraction is 1.26～3.30m3/t, which meets the relevant requirements for extraction standards. 4) When the drilling diameter is133mm, the drilling distance is 4.5m, extraction negative pressure is 15~20kPa, pre extraction time is 120d, During the mining period, the gas concentration in the upper corner is controlled at 0.12～0.43%, gas control effect is significant, The relevant research has guiding significance for the design of pumping in working faces with similar geological conditions.

The article summarized the water quality characteristics of domestic wastewater from coal mine industrial sites in northern Shaanxi through the analysis of the incoming water quality of domestic wastewater from several large-scale coal mines． Aiming at the composition and biochemical characteristics of coal mine sewage，we designed“mechanical grid + sedimentation tank + A/O tank + MBR”sewage treatment process routes of coal mine in northern Shaanxi Province． The effluent quality of domestic wastewater treatment has been monitored for a long period of time to analyze the effectiveness of domestic wastewater treatment and adjust the operating parameters according to the effluent conditions． The results of engineering practice showed that the removal effect of this process on the pollutants BOD5 and NH3-N in the coal mine domestic wastewater reacheed more than 90% and 80%，and the produced water met the water quality standard of mine reuse water． This study helped ensure the stable operation of domestic wastewater treatment during coal mine production，reduce the cost of domestic wastewater treatment，and reuse to meet the standard． The study aimed to provide relevant cases for coal mine domestic wastewater treatment and reuse technology，and provide experience and reference for the design of similar projects．

In order to solve the problems of complex multi-source data management, insufficient intelligent graphics rendering, low system integration and abstract results expression in coal mine underground drilling and geophysical exploration engineering, a "two-exploration" data fusion application system for transparent geological construction is constructed. A dual-engine architecture based on multi-dimensional cloud GIS platform and 3D model cloud rendering platform is proposed, and a two-3D integrated transparent geological support system including "digital-graphic-mode" triple linkage mechanism is developed. Through the establishment of a unified data center, the standardized filling and reporting of the "two-probe" data of 14 mines was realized, the geological attribute field was constructed by the improved anisotropic inverse distance weighted interpolation algorithm (AIDW), the high-precision modeling of geological bodies was realized by combining the Loop subdivision surface optimization technology, and the differential linkage model of drilling parameters and the three-dimensional picture space mapping algorithm were innovatively designed. The application shows that the system can increase the interpretation efficiency of geophysical exploration results by 40%, reduce the design time of water exploration and drainage holes by 65%, control the response time of 3D seismic data cutting analysis within 200ms, and the accuracy rate of hydrogeological anomaly identification reaches 92%. The triple linkage mechanism and spatial interpolation optimization algorithm proposed in this paper effectively solve the technical bottleneck of "two-probe" data fusion modeling in coal mines, and provide a scalable geological transparency solution for the construction of intelligent mines.

In view of the problems of large amount of gas emission from adjacent strata and gas easily exceeding the limit in upper corner of Sijiazhuang coal mine, the goaf is divided into four zones based on the key stratum theory. Utilizing 3DEC numerical simulations, the collapse process of the overburden is analyzed from the perspective of the velocity field. This analysis facilitates the identification of key strata and the delineation of the “four zones” for depressurization gas extraction, along with monitoring displacements at various levels within the goaf, and examining the distribution characteristics of porosity to reveal the extent of fracture development areas in the goaf. Employing digital image processing technology, the characteristics of fracture distribution within the goaf are quantitatively analyzed. It is determined that the dominant rich accumulation areas for gas extraction in the fault zone extend from 25 m to 77 m within the boundary of the working face, at a height of 44 m to 63 m. The collapse zone is identified as the area from 3m to 44m inside the working face boundary, with heights ranging from 5.5 m to 25 m. Considering the geological features of the gas, the movement patterns of the overburden, and the requirements for gas drainage, optimal positioning for the layouts of high and low drainage roadways is proposed. After field application, effective gas management results were achieved through these high and low drainage techniques, with concentrations of gas in the upper corner remaining below 0.8 %. This approach can serve as a reference for gas management in outburst-prone mines with high gas emissions from adjacent layers.

Based on the cylindrical charge blasting crater theory and similarity criteria, a series of single-hole blasting crater experiments with variable borehole depths and spacings were designed and conducted on coal bench slopes. Key blasting parameters under experimental conditions were obtained, including the elastic deformation energy coefficient, critical depth ratio, optimal burial depth ratio, and rational borehole spacing of the coal-rock mass. According to the square root similarity law for cylindrical charges, the optimal row spacing for 200 mm borehole diameter was derived as 7.60 m (preferred range: 7.26–7.60 m), with an optimal borehole spacing of 8.38–10.44 m. Combining similar engineering experience and field conditions, the optimized borehole × row spacing was determined as 9 m × 8 m. A 2D numerical model using ANSYS/LS-DYNA was established to quantitatively characterize coal-rock damage evolution and stress wave propagation under two delay time sequences (42 ms × 65 ms and 42 ms × 100 ms), revealing the control mechanism of delay time on fragmentation uniformity. The 42 ms × 100 ms sequence enhanced stress wave superposition, significantly expanded the fracture network, increased the effective fragmentation area, and improved coal-rock fragmentation uniformity. Field trials demonstrated that the optimized timing produced a gentle-sloped muck pile with moderate height, visible through-cracks on free surfaces, appropriate looseness, and reduced boulder rates. Compared to the 42 ms × 65 ms sequence, electric shovel operational efficiency increased by approximately 10%, consistent with numerical simulation results. This research advances cylindrical charge blasting parameter design theory from the perspectives of energy matching and wave interference, providing a scientifically robust and economically viable engineering solution for efficient open-pit coal mining. Keywords:Digital Electronic Detonator; Cylindrical Charge; Blasting Crater Experiment; Delay Time Combination; Coal-Rock Fragmentation Efficiency

Abstract: In order to study the composition characteristics of fracture network and the law of gas flow after coal and rock are loaded, this paper uses CT scanning technology to study the changes of fracture microscopic parameters and macroscopic fracture morphological characteristics during the loading process of coal and rock, and COMSOL numerical simulation is used to study the interaction law between coal and rock fracture and gas fluid in the process of gas flow. The results show that the fissure aperture degree of sandstone, alluvial clay and coal specimens is concentrated in 0.1-0.2mm after loading failure, and the crack dip angle is concentrated in 80°-90°, 55°-70° and 50°-90° respectively. The different length and expansion direction of the fracture lead to different fracture morphology. The sandstone penetrates the upper and lower surfaces of the rock, and the overall damage is serious. After the failure, it is ' double inclined plane shear failure ', and the coal specimen is ' single inclined plane shear failure '. The permeability of sandstone fractures is large, and the flow velocity on the whole section exceeds 0.01 m/s. The flow velocity growth area of clay and coal specimens is small. Affected by the gas flow pressure, the area where the internal pressure of the sandstone specimen is greater than 0.5 MPa is the largest, with a volume ratio of 21%, an alluvial clay volume ratio of 16%, and a coal specimen volume ratio of 11%. The change of fracture morphology causes the change of gas pressure gradient. The shape of gas pressure distribution in the vertical fracture area increases linearly, and the shape of gas pressure distribution in the fracture tip area changes with a quadratic function.

As a new type of support structure, ACC has been gradually applied in many coal mine projects. However, in engineering application, the influence of c-shaped tube insertion depth and structural surface pressure on the reinforcement of ACC is still unclear. In this paper, the laboratory test method was used to establish a tensile and shear test system of the tube cable, and the shear mechanical properties of the ACC under 5 different c-shaped tube insertion depths and 3 different initial preload conditions were tested respectively. The shear load-shear displacement curve of ACC and its shear deformation are obtained. The mechanical properties of the ACC under different c-shaped tube insertion depths on the structural plane were studied, and the effects of the structural plane with and without normal pressure and different preload loads on the shear performance of the ACC were compared and analyzed. The test results show that the insertion depth of the c-shaped tube and the positive pressure of the structural surface have a certain influence on the reinforcement of the ACC under shearing action. The c-shaped tube with a large insertion depth will increase the shear load and shear deformation of the ACC. Compared with the insertion depth of 0mm, when the insertion depth is 50mm, 100mm, 150mm and 300mm, the peak shear load increases by 20.7%, 43.1%, 50.4% and 54.6%, respectively. The greater the insertion depth of the c-shaped tube, the higher the shear resistance of the ACC The better the performance, the reasonable c-shaped tube insertion depth can effectively improve the reinforcement effect of the ACC. Compared with no positive pressure on the structural surface, the positive pressure provided by the initial preload load to the structural surface combined with the high shear performance of ACC can further improve the peak shear load of the entire support system. The peak shear load and shear deformation of ACC under different initial preload loads are significantly different, and the peak shear load and shear deformation of ACC decrease by increasing the initial preload load. The breaking of ACC is mainly due to the combination of tension and shear, and compared with pure anchor cables, ACC has a good ability to enhance the shear strength of rock mass and resist shear deformation. The results of this study can provide reference for the further application design of ACC in coal roadway engineering.

The safe operation of the auxiliary shaft hoisting system is crucial for coal mine production. However, traditional monitoring methods suffer from limitations such as strong subjectivity and limited monitoring coverage. Under this under this circumstances, we explored the application of distributed optical fiber sense technology in the auxiliary shaft hoisting system, analyzed the principle of Rayleigh scattering, Brillouin scattering and Raman scattering in optical fiber, and introduced the application of Rayleigh scattering in sound vibration monitoring. The distributed optical fiber sensor (DAS) based on coherent Rayleigh scattering was used to detect and locate the vibration signal. By constructing a dual verification system of simulation experiment platform and mine measured scene, it was proved that the system can capture the vibration and sound waves caused by regular abnormal states. The technology can effectively monitor the running state of the cage. The phase shift generated by the vibration is positively correlated with the speed and load, and the system reliability is high, which provides a new scheme for the safety monitoring for auxiliary shaft hoisting systems.

In order to solve the problems of insufficient intelligence, thermal imbalance and high energy consumption of the heating system in Shuangxin coal mine, this study constructed an intelligent heating supply control system driven by the Internet of Things. By integrating the feedback control of the return water temperature and the dynamic balance technology of the secondary network, an intelligent control algorithm based on the thermodynamic balance model was developed: the Internet of Things temperature control valve was deployed in the return pipeline, and a closed-loop control system with the return water temperature as the core index was constructed. Intelligent algorithms are used to optimize the hydraulic balance of the pipe network, and real-time monitoring and dynamic adjustment of heating parameters are realized by combining wireless communication technology. The engineering application shows that after the system transformation, the backwater temperature of key buildings (East Warehouse, Consortium Building, and Training Base) is stable at more than 45°C, the backwater temperature deviation of the whole network is controlled within ±2°C, and the balance of the pipe network is good. The comprehensive energy saving rate of the system reaches 50%. The research confirms that the multi-parameter coupling control mechanism optimizes the heating energy efficiency through the closed-loop of "perception-decision-execution", realizes accurate control of energy consumption while ensuring the quality of mine heating, and provides an economical and environmentally friendly solution for the upgrading of mine heating system in cold areas.

Abstract：To investigate the effect of pulp concentration on the spiral separation process of coarse coal slime, separation experiments were conducted to evaluate the separation characteristics under varying pulp concentra-tions. Furthermore, comprehensive analyses of the concentration effect were carried out by examining the spatial distribution characteristics of flowing film and the migration behavior of multi-component tracer particles at dif-ferent concentrations.The separation tests indicated that, under a constant feed flow rate, increasing the pulp con-centration resulted in a continuous increase in clean coal yield, whereas the ash content initially fluctuated and subsequently increased, indicating that the performance of spiral separation for coarse coal slime first improved and then declined. With an increase in pulp concentration, the distribution width of high-density particles (+2.0 g/cm3) near the inner edge of the spiral channel increased, while the proportion of low-density particles (-1.5 g/cm3) at the outer edge initially rose and then decreased. Medium-density particles (1.5~2.0 g/cm3) exhibited a notable tendency to migrate outward.Flow field measurements revealed that, with increasing feed concentration, the thickness and longitudinal flow velocity of the slurry film at the outer edge of the spiral channel decreased, while those at the inner edge slightly increased. However, the overall distribution still exhibited thicker film lay-ers and higher velocities at the outer edge.Particle tracing experiments demonstrated that finer high-density parti-cles experienced more significant misplacement at the outer edge of the spiral channel, whereas coarser low-density particles exhibited more pronounced misplacement at the inner edge.

Abstract: Based on theoretical analysis, similar simulation experiments, and field tests, a study was conducted on the movement of overlying strata and the manifestation of mining pressure in a thick sandstone roof of a large mining face in northern Shaanxi. The research results showed that the working resistance P of the hydraulic support was inversely proportional to the length L4 of the direct top suspension, and positively correlated with the length L1 of the basic top cantilever beam, the rotation angle θ, and the strength k1 γ 1h1 of the basic top overlying load; The overall distribution of rock beams in the goaf during the single mining period of the full height working face with large mining height is in an "F" shape, with a basic top initial collapse step distance of about 70 meters, a periodic collapse step distance of about 15 meters, and a mining pressure concentration coefficient of about 1.8; During the secondary mining period, the rock beams around the coal pillars are generally distributed in a "T" shape, with a basic initial collapse step distance of about 50 meters and a periodic collapse step distance of about 15 meters. The concentration coefficient of mining pressure is about 2.2, and the stress concentration of the overlying rock roof is significantly higher during the secondary mining period; The coal pillar area exhibits high stress concentration; The load strength of the support during the secondary mining period of the working face is about 21% higher than that during the single mining period. The increase in working resistance of the hydraulic support during the pressure period is significantly smaller than that during the primary mining. In addition, the stress load of the upper goaf section of the working face is significantly higher; Based on the research results, the mining party has updated a new type of hydraulic support and increased the rated working resistance, effectively improving the safety recovery coefficient of the working face and providing theoretical basis for safe and efficient production in similar mines.

The permanent magnet external rotor hoist has subverted the traditional driving mode, enhanced the energy efficiency ratio, and facilitated the green, efficient, and energy-saving development of mining hoisting equipment. To enhance the speed control performance and robustness against load disturbance variations of the permanent magnet external rotor hoist, a composite sliding mode control method combining an improved disturbance compensation-based sliding mode controller and a sinusoidal switching sliding mode disturbance observer was proposed. The load changes were observed in real time, and the observed values were integrated into the control, improving the dynamic response capability during sudden load changes. Subsequently, a multibody dynamics load model of the permanent magnet external rotor hoist was established using Simulation X for joint simulation, and the dynamic characteristics of the permanent magnet external rotor hoist under multiple working conditions were investigated. The joint simulation results indicate that the load observer can accurately observe load changes and compensate for the disturbance values. The designed composite sliding mode control system exhibits superior dynamic performance compared to the traditional sliding mode control. The permanent magnet external rotor hoist based on the composite sliding mode control strategy can fulfill the requirements of stable heavy-load operation under diverse working conditions.