The fracture movement of rock layers caused by coal seam mining has led to a series of mining damage and environmental problems. In recent years, grouting and filling of overburden separation layer has been more and more applied to release of " under-three" pressed coal. In order to systematically introduce the test results of grouting and filling in overburden separation layer, this paper makes a statistical analysis on the effect of subsidence reduction test by grouting and filling in separation layer in recent 40 years. This paper explores the influence of geological factors, mining factors, and construction factors on the grouting filling of overlying strata separation, analyzes the factors that restrict the promotion and application of overlying strata separation grouting, introduces the new progress of current overlying strata separation grouting technology in grouting theory, grouting equipment, drilling construction, and grouting technology, and explains it in conjunction with the grouting filling case of overlying strata separation in the 3117 working face of Xiadian Coal Mine, Lu'an Group. The results show that the grouting and filling of overburden separation layer can not be simply homogenized in the application process, and geological factors are the primary conditions for the application of grouting and filling of overburden separation layer; mining factors have an important influence on the formation of separation space; grouting technology has a direct impact on the settlement reduction effect and economic benefits of grouting engineering.

In deep mines, an analogy ‘isolated island’ working face with one side of the local coal seam and one side of the lower coal seam is easily produced in the later stage of close-distance coal seam group mining in the upper coal seam, and its position design has a direct impact on the mining intensity of the working face. Through on-site investigation and analysis, the ‘下’ type structure of the surrounding rock of the analogy 'isolated island' face of the close upper coal seam is proposed and the potential mining risk factors are elaborated. Three types of layout schemes are proposed based on the positional relationship between this analogy ‘isolated island’ face and solid coal in the lower coal seam, and eight kinds of island surface layout models are established based on discrete element numerical software. It is concluded that the solid coal in the coal seam should be staggered downwards on the analogy 'isolated island' face, and when the staggered distance is about 25 m, the peak stress increase coefficient of the solid coal seam along the trough decreases to below 1.5, and the stress of the coal pillar seam apparently decreases, which is suitable for this arrangement. Considering that there is a thick and hard roof on this analogy ‘isolated island’ face, the method of reasonable layout+ roof pre-splitting+ re-mining after pressure relief is put forward, which provides reference and reference for related projects on site.

Based on the design practice of the driving room for the main inclined shaft of Yangmahe Mine, the architectural design of the driving room was explored from two aspects of plane layout and vertical layout. At the same time, the key points and calculation points of structural layout for the driving room were briefly introduced. Finally, the calculation methods for the natural frequencies of the driving platform under horizontal and vertical vibrations were studied, and the design principles for vibration control were given. The design of this driving room will provide references for similar engineering projects.

In order to solve the problem of insufficient database resources and analysis tools for coal and coalbed methane development, based on the principle of collaborative computing and distributed storage of big data technology, the design scheme of big data platform for coalbed methane is proposed, the big data interconnection mechanism based on cloud technology is established, and the coalbed methane development and utilization model base based on big data mining technology is constructed. According to the system architecture design and function design, a big data platform with Hadoop as the core framework was built, and diversified applications were carried out in government management departments and coal enterprises, providing data basis and decision-making basis for coordinated mining of coal and methane and rational layout of coalbed methane development and utilization.

The coal resources in Xinjiang are mainly distributed in the ecologically fragile Gobi region of northern Xinjiang，where the climate conditions are bad，water resources are short，and the ecosystem is extremely fragile. Once the disturbance is disturbed，it is extremely difficult to recover for a short time.To resolve the conflict of development of coal resources and ecological environment in Xinjiang,Four measures for the recovery of open-pit dump in Gobi mining area of Xinjiang are proposed，which are respectively Gobi gravel stripping and reconstruction，direct rolling or sprinkling rolling，construction of Gobi sand barrier and exploitative recovery.

In recent years, the Huainan mining area has gradually entered deep mining, and engineering and technical problems such as high rock stress, complex environment, weak and fractured rock, poor stability, and severe deformation have become increasingly prominent. The limitations of traditional support technologies are becoming increasingly apparent. Therefore, it is imperative to explore new tunnel rock control technologies and solve the technical problems of deep coal tunnel support. This article is based on the geological conditions of Pansan Mine in Huainan Mining Area. Theoretical analysis, numerical simulation, industrial experiments, on-site measurements, and other methods are used to conduct a systematic and in-depth study on the problem of controlling the surrounding rock of coal tunnels under the influence of deep strong mining. The characteristics of the surrounding rock of deep strong mining coal tunnels in Huainan Mining Area are analyzed, mainly including large burial depth, large changes in lithology, large tunnel sections, multiple composite roofs, and low coal strength, Based on the occurrence characteristics of surrounding rocks in coal tunnels in Huainan mining area, the technical difficulties in controlling deep strong mining coal tunnels were analyzed; In response to the technical difficulties in controlling the surrounding rock of the deep strong mining coal roadway in the Huainan mining area, an integrated collaborative control technology system of "stress optimization, surrounding rock modification, and anchoring reinforcement" has been established, and an innovative integrated surrounding rock control technology of "top cutting pressure relief, grouting reinforcement, and thick anchoring layer reinforcement" has been innovated; Industrial experiments were conducted on the 2121 (3) transportation channel. During the mining process of the tunnel, the maximum cumulative deformation of the two sides of the transportation channel was 436.6mm, and the maximum relative displacement of the bottom plate was about 390.1mm, which is less than 50% of the deformation under the original support method; The shallow rock layer of the 2121 (3) transportation trough roof has separation and crack development within the range of 1.5~1.8m. The integrity of the deep roof rock layer is good, and it has good bearing performance, which can effectively maintain the stability of the tunnel. This verifies that the technical system has good maintenance and control effects on the stability control of the surrounding rock of the deep strong dynamic pressure coal tunnel.

The stability control of the surrounding rock of the goaf retaining roadway under the influence of repeated mining is an important guarantee for ensuring safe mining of the working face under the conditions of adopting the roadway layout technology. Especially, it is of great safety significance for the western mining area to achieve simultaneous mining between the coal body and the coal pillars between the working face and the remaining face when the original roadway layout technology of double roadway excavation is changed to the goaf retaining roadway technology. This article is based on the engineering background of the transformation of the roadway layout technology from the original double roadway excavation to the goaf retaining roadway during the simultaneous extraction of the coal body of the 12408 fully mechanized mining face and the remaining coal pillars between the 12407 working face in Ulan Mulun Coal Mine, Through a large amount of on-site measured data, the full life cycle failure characteristics of the surrounding rock of the goaf retaining roadway and its influencing factors of instability and deformation are summarized and analyzed; The FLac numerical simulation software was used to analyze the response mechanism of coal pillar recovery between faces to the instability of surrounding rock in the goaf retaining roadway, and multiple measures and techniques were proposed to solve the instability problem of surrounding rock in the remaining section of the 12408 external return air passage. The results indicate that the main factors leading to the instability of the surrounding rock of the retained roadway are the influence of secondary dynamic pressure superposition, the coupling effect of bedrock lithology characteristics and burial depth, and the irrational matching of tunnel section support strength and mining strength parameters; After adopting the coupling control technology system of reinforcement support, adding unit supports, and reasonable control of mining speed, the remaining section of 12408 working face has a top separation layer value of 70mm during the mining process, a maximum subsidence of 40mm on the roof, and a maximum displacement of 23mm on both sides. The overall change is small, and the deformation of the surrounding rock does not affect safe mining, and is within the controllable range.

In view of the creep occurred in some areas of the transport roadway of 071601 fully mechanized mining face in Lingxin Coal Mine, the original support scheme can not better control the surrounding rock deformation. The creep effect and support technology of inclined coal seam roadway are studied by means of theoretical analysis, numerical simulation and field test. It is determined that the stress concentration at the end of roadway and coal pillar is more serious in the stage of driving and mining. And by increasing the initial supporting force, it plays a positive correlation role in controlling the range of plastic zone of surrounding rock of mining roadway. after the simulation and comparative analysis of original support and optimized support scheme under multi-stage, it is determined that after the optimization of support scheme, it can effectively improve the bearing capacity of shallow surrounding rock of roadway and slow down the small range expansion of surrounding rock failure, which shows that the support scheme can effectively improve the anti-deformation capacity of surrounding rock of roadway. In the field application, the optimized support scheme can improve the control ability of the roof and floor and the surrounding rock of the two sides respectively, and the deformation control effect can be improved by 75.84% and 65.49% respectively, that is, the optimized support scheme of the whole roadway is more effective for the control of surrounding rock and provides an important guarantee for mine safety production.

As the main water inrush source of coal mine water disaster accidents, goaf water accumulation has become an important goal of mine water prevention and control. This paper puts forward a series of engineering and technical schemes of "compound exploration and directional exploration" of mine groundwater based on the engineering background of the prevention and control of old empty water in coal seam 5 under the east wing of Yushuling Coal Mine. It includes the technical methods of compound exploration of mine underground water accumulation area (including three stages of macroscopic geophysical exploration, meso drilling exploration and microcosmic exploration) and long distance directional drilling precision exploration and drainage engineering scheme (including long distance directional drilling equipment technology and borehole layout design, etc.). And the implementation effect of the project is monitored and evaluated to realize the drainage of water in the goaf as a whole and solve the hidden danger of water damage caused by mining and layout in the working face. The engineering practice shows that the series of engineering technology of "compound exploration and directional exploration" has been implemented for 6 months, the accumulated empty water is about 226000m3, the water pressure decreases from 1.42MPa to 0.9MPa, and the water discharge effect is good, which can provide reference and guidance for mine exploration and discharge projects under similar conditions.

In order to explore the two key parameters of "hydraulic slope" and "critical flow rate" in the design of in-situ filling pipeline system, the existing hydraulic slope and critical flow rate models were modified. Taking A material as the research object, indoor hydraulic experiments were conducted to investigate the actual hydraulic slope and critical flow rate of A material slurry under different inclination angles and mass concentrations. The parameters were estimated and the accuracy of the model was explored, the engineering inspection was conducted based on the in-situ filling of the 7105 old roadway in a coal mine in the southwestern region of Shandong. The research results showed that: (1) as the inclination angle increases, the hydraulic slope gradually increases, and the inclination angle influence coefficient α The approximate linear relationship with the inclination angle of the pipeline; The near flow velocity is influenced by both the inclination angle and concentration, and the higher the concentration and inclination angle, the greater the critical flow velocity. (2) Obtained from experimental data α、β fitting the formula and incorporating it into the correction model, the error of the hydraulic slope model results is within 10%, and the error of the critical flow velocity is within 5%; (3) The on-site filling pipeline system designed based on two key parameters is unobstructed, and there is no siltation or severe wear of the pipeline, proving the feasibility of the values of hydraulic slope and critical flow rate in practical applications.

Intelligent construction is an important precondition for high-quality development of coal industry, shaft is the throat of mine, Tatei intelligent construction is an important guarantee for the safety and efficiency of shaft construction. This paper describes the development of technical equipment for main construction methods such as drilling and blasting construction, mechanical tunneling construction and special shaft sinking during the period of shaft construction in coal mine, and analyzes the present situation of intelligent technology for construction technical equipment in Tatei. , The Intelligent Technical Route, integrated system scheme and intelligent development direction of Tatei's main construction methods are pointed outit also points out the development direction of the intelligentization of Tatei's main construction methods, such as drilling and blasting construction, mechanical tunneling construction and special shaft sinking construction.

Aiming at the problem of strong ore pressure in super-high mining face with shallow buried thick hard roof, based on support pressure and in-situ microseismic overlying rock monitoring data, the ore pressure and overlying rock activity regularity in Caojiatan 10m super-high mining face were studied. The results show that the first pressing step of the basic top of 10m super-high mining face is 49.35 m, the average pressing step of periodic working face is 21.89 m, and the average dynamic load coefficient is 1.49. The working face has the phenomenon of "size cycle" to press, and during the big cycle to press, the working face to press step increases significantly. The working resistance of the support increases not significantly during non-pressure period, but significantly during periodic pressure period. The living column of the support has obvious shrinkage, especially during the "big cycle" period, the average and maximum shrinkage of the column reach 686.12 mm and 1321.35 mm respectively. It has the characteristics of long pressing step, long pressing duration, frequent pressing, strong dynamic load ore pressure and severe coal wall sheet. The active area of microseismic events is located in the working face trend, 0~130 m away from the center of the working face, where 110~130 m is the peak area. The 40~60 m microearthquakes in the roof of coal seam have low frequency but high energy, which is the dominant rock formation of strong ore pressure. The spatial and temporal distribution of microseismic events is in good agreement with the rule of ore pressure. High-energy microseismic events usually occur before the ore pressure appearance of the working face, and have a good correspondence with periodic pressure. The reliability or matching degree of ore pressure prediction is relatively high.

Aiming at control challenges such as slow retraction speed of hydraulic supports in fully-mechanized top-coal caving working face, sinking of hydraulic support base plate during steering process, and easy tilting frame, the comprehensive methods including on-site investigation, numerical simulation, and theoretical analysis methods were adopted to study the safety retraction platform of hydraulic supports in fully-mechanized top-coal caving (FMTC) working face. The main structure and operating process of the retraction platform were analyzed, and the stress and displacement characteristics during the interaction process between hydraulic supports and retraction platform were simulated and studied. Field industrial tests were conducted on a typical FMTC working face in Shuiyu coal mine, and the application effect was good, providing certain reference for the safe retraction of hydraulic supports in similar FMTC working face.

In order to improve the technical level of water damage prevention for burnt rock , and reduce the occurrence of water hazard accidents in the Aai mining area of Xinjiang, the distribution characteristics and water richness characteristics of the aquifer in the burnt rock in the study area were introduced; Based on the relationship between the aquifer of burnt rock and the location of the mining area, the formation mechanism of water channels, and the direction of water inflow from burnt rock, the types of water damage caused by burnt rock in the study area were classified; Proposed the use of a combination of surface drainage and underground drainage for the prevention and control of water damage caused by burnt rock; We have studied the evaluation method for water hazard control effectiveness based on hydrophobicity, water level dynamic changes, and drilling verification, and selected typical working faces for application. The results showed that the water damage caused by the burnt rock in the Aai mining area can be divided into three categories: lateral water inrush from excavation disturbance cracks, water inrush from the top of mining induced cracks, and water inrush from the top of concentrated water channels; The cumulative drainage volume of burnt rock water in a typical working face was about 2.192 million cubic meters, and the average water level in the aquifer decreased by about 40 meters. Only 7.5m3/h of water gushed from the T1 hole outside the stop mining line of the working face, and there was no water in the remaining areas, indicating that the vast majority of the burnt rock water had been drained and the drainage effect was significant. The research results provide reference for the prevention and control of water damage caused by burnt rocks in the region.

Aiming at the problems of serious dust pollution and poor dust removal effect on the fully-mechanized mining face with large mining height, this study took Daliuta Coal mine mining layer working area as an example, and optimized the spray parameters by using numerical simulation. By combing and comparing the existing spray dust removal technologies, a comprehensive dust removal technology combining support dust collection, spray inside and outside coal machine and dust source tracking spray was proposed. The performance of the optimized spray dust removal system was verified by field experiments, and the field application and effect test were carried out. The results show that HH9.5 nozzles are preferred when the wind speed is 1.0~1.5m/s, and HH9.5 and SB203 nozzles are used when the dust production is large. With the increase of pressure, the spray area and high concentration spray area showed an upward trend, and the economic benefit was the best when the pressure was 6MPa. The dust removal rates of total dust and exhaled dust can reach 92.69~96.24%, 83.61~90.07%, and the total dust mass concentration in the working face space can be as low as 20mg/m3 and 10mg/m3 respectively. In summary, the spray comprehensive dust removal technology can effectively reduce the dust concentration of the working face, improve the safety level of coal mine production, and provide a useful reference for the dust control work of the fully-mechanized mining face with large mining height.

Aiming at the technical problems such as large deformation and serious support failure of deep soft rock roadway in a mine of Pingmei, the deformation characteristics and instability failure mechanism of high stress soft rock roadway are analyzed by means of field investigation, theoretical analysis, numerical simulation and industrial test. The synergistic integrated control mechanism of roadway surrounding rock is put forward, and the synergistic integrated control scheme of ' deep and shallow anchoring grouting + deep anchor cable reinforcement + pressure relief groove pressure relief ' is designed. Through theoretical calculation, it is veri-fied that the ultimate bearing capacity of the cooperative surrounding rock bearing body after support is greater than its bearing capacity; FLAC3D simulation shows that the design scheme can make the internal and external surrounding rock structure cooper-ate with each other, fully release the plastic deformation energy around the roadway, and evenly distribute the surrounding rock load. After the roadway is re-supported, the influence range of surrounding rock stress is transferred to the 10 m deep area of the roadway, and the surrounding rock-support achieves a bearing structure with uniform load. The monitoring data of the mine show that after one year of roadway repair, the maximum displacement is less than 4% of the width of the roadway, the maximum sub-sidence is less than 5% of the height of the roadway, and the deformation of the roadway tends to be stable.

Aiming at the problems of high stope stress, large deformation amount and large roof fracture energy of the working face under the condition of deep buried thick sandstone roof remining, the FLAC numerical simulation of the stress evolution law and stope displacement evolution law of the 130207 deeply buried high-stress stope is simulated, and the results show that when the working face is advanced to the primary square and the second square, there will be high stress concentration, the concentration coefficient can reach up to 2.5~4.0, and the horizontal displacement of the return air lane gang during the second square period can reach 390mm. The kick drum volume can reach 413mm. In order to ensure the safe recovery of the working face, a regional hydraulic fracturing and pressure relief scheme was formulated, and the key disaster-causing layer of the working face was calculated according to the key layer theory and composite beam theory 130207 the key disaster-causing layer of the working face was 22.83m thick coarse-grained sandstone layer and 40.23m thick coarse-grained sandstone layer, and the rupture pressure was 13.06MPa according to the calculation formula of Hubbert-Willsi non-permeable formation rupture pressure. After regional hydraulic fracturing, the working face cycle pressure step distance and the continuous pressure distance were significantly reduced, the influence range and stress concentration coefficient of the advanced supporting pressure were significantly reduced, and the daily maximum energy and daily average energy of the working face were significantly reduced, which indicated that the hydraulic fracturing technology in the directional area had good effect and had promotion and application value.

In order to prevent the occurrence of water damage in coal mine, it is very important to develop the prediction of mine water inrush, especially the accurate prediction of water inflow. According to the occurrence conditions of near vertical coal seam, a hydrogeological model is established by combining theoretical analysis, numerical simulation and engineering verification, and a calculation method of dynamic water inflow in open pit conversion of near vertical coal seam under multiple water gushing sources is proposed. The results show that the continuous replenishment of loose deposits in open pit can not be ignored under the conditions of open-pit switching mining near vertical coal seam. The shallow mining recharge characteristics of "pit water filling - infiltration recharge - water filling - recharge" and the deep mining recharge characteristics of "combination of bedrock aquifer reserve release and vertical open pit water recharge" are defined. Taking the Xianfeng coal mine in Qinghai Province as an example, the dynamic calculation of mine water inflow is carried out, and the comparison with the measured results proves that the method is feasible. The research results can provide a basis for mine water control work and reasonable installation of water control and drainage facilities.

This article explores the influence of the interactive ratio of limestone powder and fly ash on the performance of paste filling materials. Prepare a series of samples using limestone powder instead of fly ash at 0, 25%, 50%, 75%, and 100% substitution percentages. The working performance and compressive strength of the paste filling body were evaluated by testing indicators such as expansion rate, slump, bleeding rate, setting time, and compressive strength. The research results indicate that the interaction ratio of limestone powder and fly ash has a significant impact on the performance of mineral paste filling materials. As the replacement amount of limestone powder increases, it can effectively reduce the bleeding rate and setting time of the filling material, and improve the expansion rate of the paste. When the replacement amount is around 25%, the compressive strength of the filling material is enhanced. When the curing period is greater than 3 days and the replacement amount of limestone powder is greater than 25%, the compressive strength decreases with the increase of the replacement amount.

Physical simulation test is one of the important scientific means to study rock burst of coal. Developing similar materials with low strength and high impact inclination is the key to physical simulation of rock burst. Aiming at the material performance requirements, the impact energy index and brittleness index were introduced, and four factors including calcium carbonate content, barite powder content, gypsum cement mass ratio and water content were selected by orthogonal experimental design method and sensitivity analysis method. A total of 25 groups of orthogonal ratio schemes with 4 factors and 5 levels were designed. Uniaxial compression and acoustic emission characteristic experiments were carried out to obtain stress-strain curve and acoustic emission evolution characteristics of the samples, determine the performance parameters of each group of samples such as strength and impact energy index, and compare and analyze the variation rules of each test parameter under different levels of four influencing factors. The impact energy index and brittleness index were used as screening conditions to select similar material ratio schemes. The experimental results show that water content and calcium carbonate content are the main factors for the preparation of low-strength, high-impact and strong coal-rock similar materials, and the brittleness degree and strength of similar materials can be adjusted by changing the mass ratio of gypsum to cement. Taking the impact energy index KE ≥1.5 and brittleness index BIzhou ≥0.2 as the selection criteria, six groups of low-strength and high-impact tendency materials are obtained. When the water content is 19%-25% and the calcium carbonate content is 26%-32%, the impact tendency of the prepared sample can meet the test requirements. During sample loading, acoustic emission events were not active before the yield stage, but after entering the yield stage, the ringing count increased sharply and high energy damage occurred, and the trend of "smooth transition and sharp rise" occurred before and after the yield stage.

Coal mine water disaster is one of the main disasters in coal mines, with highly destructive.It not only prone to causing property damage to enterprises, but also leads to heavy casualties, and it is difficult to carry out emergency rescue and resume production. The water channel is one of the three elements of coal mine water disaster. The failure of coal mine floor can generate cracks and also trigger microseismic events. Therefore, microseismic monitoring technology can monitor the depth failure of the working face floor. Due to factors such as non-uniform rock layers, undulations in the floor, and hidden structures, the depth of floor failure is not uniform. In this paper, the well ground hole microseismic monitoring technology is used to monitor the mining damage of the 11916 working face floor in Gequan Mine. A three-dimensional geological model of the working face floor is established based on data such as floor contours, tunnel exposure, and floor grouting holes. Subsequently, the floor rock stratum was divided into several grids and the microseismic energy density of each grid was calculated, thereby obtaining the isosurface of microseismic energy density and deducing the floor failure surface. The segmented water pressure test was used to detect the depth of the floor failure in different areas. The results showed that the floor failure surface and its change trend using this method were highly consistent with the water pressure test results, confirming the feasibility and availability of this method.

To study the gas migration laws of coal-rock systems in structurally developed areas under mining influence, a dynamic evolution model of coal body permeability under mining influence was constructed. By combining the interaction of stress field, deformation field, and seepage field of coal-rock, the mechanism of gas migration in the coal body was analyzed in terms of fluid-solid coupling. Taking the Sangbei mining area as the engineering background, a combination of theoretical analysis, field measurement, and numerical simulation was used to analyze the influence of regional structures on gas storage in the Sangbei mining area. It was pointed out that the Sangbei integration area is located in the southeast of the Ordos Basin Yishan Slope, where the structure is complex, and its impact on gas storage in coal seams is reflected in folds, faults, and collapse column structures. Based on field measurements, it was found that the vertical and horizontal stresses at measurement point 7 are the smallest, and the vertical stress of the 8 measurement points is between 4.5MPa and 7.2MPa, increasing linearly with burial depth, mainly dominated by vertical stress. The stress is influenced by gravity and structural movements, with horizontal structural movements playing a major role. The current stress state is controlled by the most recent structural movements, and after the movement, most of the stress is released with a small amount remaining. Through the multi-field coupling model of stress-injury-seepage of gas-containing coal seams, a numerical simulation scheme was established, and different parameters were set to simulate the gas migration in coal seams under different extraction times. The results show that as the extraction time increases in the original area, the area of gas pressure change expands, in the fully unloaded area, the gas pressure decreases over time and is related to the degree of unloading, and in the structurally developed area, the change in gas pressure is affected by the degree of structural development, with the higher the degree of development, the smaller the impact.

Aiming at the problem of column stalling during the lowering process of palletised hydraulic strut, the balancing circuit is improved based on the externally controlled constant pressure speed control valve, and the load bearing characteristics of the column under load are investigated. The simulation model of hydraulic support balance circuit was established by AMESim software to simulate the work-ing process of the column , and changed the structural parameters of the externally controlled constant pressure speed control valve to analyse the load-bearing characteristics of the column as well as the flow characteristics of the externally controlled constant pressure speed control valve.The results show that: when the column is impacted, the safety valve opens to unload; when the column goes down, the balancing circuit works to prevent the column from stalling.Reducing the diameter of the damping hole and the area of the regulating piston of the externally controlled constant pressure speed control valve can enhance the response speed of the system, the stability of the balancing circuit can be improved, and get the suitable load bearing characteristics of the column.

Accurate prediction of the cold load is the basis for formulating a cooling program for high-temperature coal mining face, improving the underground working environment, preventing heatstroke of workers, and breaking the dilemma of high-temperature mines stopping work and production in summer. The cold load calculation method of coal mining face based on the prediction of the wind temperature of the whole wind flow path is proposed in the engineering background of the 10th mine of Ping Coal Co. A numerical model of the temperature field of the coal mining face was established, and the dependence of the inlet air temperature on the temperature value of the temperature control target area was analyzed; the target temperature value of the temperature control target area was set, and the cold load of the coal mining face before and after refrigeration was calculated by the enthalpy difference method. The results of the study show that the temperature control target area is 50 m ahead of the working face at the upper end of the coal mining face, and the dependence relationship between the inlet temperature and the target temperature of the temperature control target area is as follows: y=89.57-72.88×0.99x; the inlet air temperature is 30 ℃ and the temperature of the target area of the temperature control area is 35.7 ℃ before the cooling down. After cooling, the inlet air temperature is 13.6 ℃, and the temperature of the temperature control target area is 26 ℃; the enthalpy of the inlet airflow at the working surface before cooling is 85.53 kJ/kg, and the enthalpy of the airflow at the temperature control target area is 128.88 kJ/kg; after cooling, the enthalpy of the inlet airflow at the working surface is 28.36 kJ/kg, and the enthalpy of the airflow at the temperature control target area is 66.77 kJ/kg; the cold load of the working surface is 2,286.8 kW. The cooling capacity of the refrigeration unit is 2300 kW, and the average temperature of the working surface is reduced by 7℃~10℃ and humidity is reduced by more than 20% after the operation of the unit, so the effect of cooling and dehumidifying is obvious.

In low-light and high-dust concentration environments of fully mechanized mining faces, ground-penetrating radar (GPR) is an effective method for addressing the challenge of coal-rock interface identification. To address the issue of existing research neglecting the impact of rough coal-rock interfaces on identification results, this study employs the Monte Carlo method to generate rough surfaces with varying root mean square (RMS) heights and correlation lengths. These surfaces are superimposed onto a coal-rock interface with undulating geological features. Using the finite-difference time-domain (FDTD) method, forward modeling experiments are conducted to investigate the impact of coal-rock interface roughness on the position of the interface and the amplitude of backscattered waves. The experimental results indicate that when the RMS height of the rough coal-rock interface exceeds 1/4 of the wavelength, multipath effects cause electromagnetic wave interference, leading to poor identification results. When the RMS height exceeds one wavelength, the identification essentially fails. The correlation length of the rough coal-rock interface has a smaller impact on identification results, with the variations in interface position and backscattered wave amplitude closely following the interface undulations. In practical applications of GPR for coal-rock interface identification, it is crucial to account for the impact of rough interfaces on identification results and to perform corresponding time delay and amplitude compensation. Increasing the root mean square height of the rough air-coal wall interface causes its echo to interfere with the coal-rock interface echo at local positions, making the identification of the coal-rock interface difficult.

The preparation of coal water slurry using coal chemical wastewater has achieved comprehensive utilization of pollutants in wastewater, minimizing the adverse impact of wastewater on the environment. This study selected Xinjiang lignite and prepared coal water slurry using sodium naphthalene sulfonate as a dispersant. Explored the influence mechanism of phenol and ammonia nitrogen in wastewater components on the slurry characteristics of coal water slurry, and explored the interaction forces between particles in the corresponding liquid-phase environment based on atomic force microscopy (AFM). The results showed that the inter-particle force had a good correspondence with the rheology of the slurry, in which: with the increase of phenol concentration, the repulsion force of the AFM particle probe increased and the action distance was shortened during the probe feeding process, while the adhesion and action duration decreased during the probe withdrawal process, indicating that the addition of phenol reduced the thickness of the hydration film and released more free water, which was manifested as a decrease in the apparent viscosity. With the increase of ammonia nitrogen concentration, the AFM particle probe feeding process and the withdrawal process mainly showed the increase of action distance, indicating that the addition of ammonia nitrogen increased the thickness of the hydration film and bound more free water, which showed that the apparent viscosity increased rapidly when the ammonia nitrogen concentration was high enough. In addition, it is found that even when the composition of the liquid phase was different, the distance and the maximum attraction value still had a good monotonic correlation with the apparent viscosity during the needle extraction process, which provides a mechanistic guidance method for in-depth exploration of the regulation of particle surface interface, wastewater environment regulation and the research and development of additives in coal water slurry system.

In order to solve the problem of low screening efficiency caused by the accumulation of materials at the feeding end of a flip-flow screen, a four-mass variable amplitude flip-flow screen consisting of one main frame and three floating frames is proposed. The transfer function method is used to obtain the expressions of the amplitude and phase of the main and floating frames; The amplitude and phase -frequency characteristic curves of the main and floating frames are plotted, the effects of changing the mass of the frame and the stiffness of the spring on the dynamic characteristics of the screen are analyzed. The amplitudes of the three floating screen frames on the working frequency were adjusted by the multi-objective optimization algorithm, so as to make the materials experience the varying vibratory amplitudes during the screening process. The results show that: The size of the four resonance frequencies are determined by the mass of the screen frames and the stiffness of the springs; the stiffness of the shear springs mainly affects the second, third and fourth-order resonance frequencies, while the stiffness of the vibration isolation springs mainly affects the first-order resonance frequency; In the process of designing a four-mass screen, the multi-objective optimization algorithm can be used to choose the appropriate parameters, so that the amplitude ratio of the three floating screen frames can reaches the preset value at the working frequency.

Based on the purpose of fine coal slurry separation and rational utilization, in order to enhance the flotation recovery and separation effect of medium ash coal slurry, and achieve the separation of three products of fine coal slurry: low ash clean coal, medium ash coal slurry, and high ash mud gangue, this paper selects two samples of flotation clean coal and medium ash coal slurry, and investigates the flotation effect under different sorting parameters through flotation experiments. The differences in flotation behavior between flotation clean coal and medium ash coal slurry are studied, and the interaction between strong/weak hydrophobic substrates and bubbles during liquid film thinning process is measured using atomic force microscopy. Research has shown that the contact angle of flotation clean coal is 109.25 °, which is 28.62 ° higher than that of medium ash coal slurry; Flotation clean coal contains a large number of cationic groups such as alkyl and amino groups, while medium ash coal slurry contains a large number of oxygen-containing functional groups such as carboxyl and hydroxyl groups. Increasing the amount of diesel and secondary octanol, as well as increasing the flotation stirring speed, can help improve the recovery efficiency of flotation clean coal and medium ash coal slurry; Increasing the inflation volume can improve the recovery efficiency of flotation clean coal, but the recovery efficiency of medium ash coal slurry is reduced. The flotation rate of flotation clean coal is significantly higher than that of medium ash coal slurry, and under the same flotation conditions, flotation clean coal preferentially floats out. For the enhanced recovery of medium ash coal slurry, the order of influence of sorting parameters is stirring speed>slurry concentration>aeration amount>foaming agent>collector. When strengthening the separation and recovery of coarse ash coal slurry, the separation conditions of "high dosage of reagents, strong stirring speed, low gas charge, high slurry concentration, and extended flotation time" should be adopted; For the separation of flotation clean coal and medium ash coal slurry, the separation conditions of "low reagent dosage, low stirring speed, high gas charge, low slurry concentration, and reduced flotation time" should be adopted. The theoretical values of the critical liquid film thickness between strong/weak hydrophobic substrates and bubbles are 39nm and 16nm, respectively. Under the attractive separation pressure, bubbles break through the liquid film and adhere to the substrate. When the thickness of the liquid film thins to the hydrophobic range, the total separation pressure begins to shift towards attraction, and the thinning of the film drives a sharp increase in pressure, causing the liquid film to rupture under the action of hydrophobic forces.

A multi-channel online high-density electrical method instrument system for mining based on ARM and FPGA is designed to address the limitations of narrow application range and low automation level of current centralized DC electrical method instruments in coal mine hydrogeological exploration. The system features a six channel electrical method instrument substation, which uses a high-performance ARM processor to transmit electrical data and control signals. A 24 bit AD and FPGA programmable logic chip are used to perform high-precision sampling and parameter configuration of on-site electrode signals. An intrinsic safety high-voltage drive circuit is designed at the electrical method instrument substation through an IGBT circuit. The main control circuit of the electrical method instrument slave adopts a low-power microprocessor STM32L431, and a micro relay is used to control the electrodes for flexible implementation. Configuration and control, ultimately achieving multi-channel automatic pole running operation. Through system software, the electrical instrument system can be remotely controlled to set parameters, collect sensor data, and perform data inversion in the coal mine environment, achieving the entire engineering application of geological exploration and mine water exploration. The actual test results of the system indicate that it has the characteristics of accurate data sampling, strong anti-interference ability, high application efficiency, and accurate data inversion results, which meet the needs of applying DC electrical exploration in coal mine hydrogeology.

The use of inspection robots instead of manual inspection is an important means to achieve intelligent mining in the visualization remote intervention mode of fully mechanized working face. Based on the systematic analysis of the research status of inspection robots in fully mechanized working face, difficulties such as adaptive working face of inspection robots and environmental perception and positioning with multi-sensor fusion are proposed. By designing an inspection robot system suitable for fully mechanized mining face, Solved the problem of adaptive comprehensive mining face for inspection robots, and achieved functions such as video image acquisition, drum tracking, and rapid inspection of the working face environment. After on-site verification, the main engine of the inspection robot has a endurance time of ≥ 3.5h, a endurance mileage of ≥ 4.5Km, a positioning accuracy of ≤ 0.1m, and a maximum inspection speed of 0.35m/s, providing a complete and reliable solution for truly realizing the replacement inspection of inspection robots.