Based on the calculation formula of the anchorage force of a single resin bolt,this paper explores the relationship between the anchorage force and anchorage length of resin bolt and the wall thickness of coal mine shaft,and derives the checking formula of shaft wall thickness based on the design anchorage force of resin bolt.At the same time,this paper discusses the wall thickness of shaft wall and the relevant specifications when using resin bolt to fix shaft equipment in general conditions in the form of a case.

A new ventilation system is proposed to improve the intake side structure of the coal mining face in response to the poor disaster resistance of the ventilation system in China’s coal mining face in dealing with the frictional heat generated by the main conveyor belt and belt fires. The new ventilation scheme takes the belt roadway of the coal mining face as an independent air supply point, forming a “one-intake, two-consumption-point” ventilation system. On this basis, the advantages and disadvantages of the “one-intake, two-consumption-point” ventilation system are analyzed, and an example is used to illustrate its scope of application and feasibility of implementation. The research results show that the new ventilation system can not only enhance the disaster resistance of coal mining face in case of fire, but also alleviate the heat damage of high-temperature coal mining face and improve the air quality of coal mining face. The formation of this new ventilation system requires a small amount of engineering, which can be achieved by adjusting the demolition time of relevant ventilation structures and adding a small amount of engineering on the basis of the original “two-intake, one-return” coal mining face ventilation system. The calculation results indicate that the necessity of using this scheme is more prominent when the length in the advancing direction of the coal mining face is greater than 2500 m.

The heat pipe structural parameters of the gravitational heat pipe heat exchange system for mine air return heat recovery and intake air heating remain largely the same under different operating conditions, resulting in low efficiency of waste heat recovery from mine air return and inability to meet the design requirements for intake air temperature. To address the technical challenge of lacking targeted theoretical support for the design of key parameters of this system and its heat pipe components, a design calculation method for key parameters of the mine air return and intake gravitational heat pipe system was proposed based on the heat exchange model of the gravitational heat pipe system. This method was applied to a mine in Yinchuan, and its heat exchange effectiveness was compared with three other typical gravitational heat pipe coal mines. The results showed that the gravitational heat pipe heat exchange system at this mine increased the intake air temperature from -31.5°C to 4.1°C, meeting the coal mine safety regulation requirement of an intake air temperature ≥2°C, and demonstrated a more noticeable improvement compared to other projects, thereby confirming the effectiveness and practicality of this method.

In order to solve the problems of serious deformation and damage of the surrounding rock and low support strength of the impact ground pressure roadway, the influence of stress wave on the roadway was analyzed, the high-impact toughness bolt (cable) was developed, and the synergistic anti-scouring mechanism of the high-impact toughness bolt and the high-strength anchor cable was proposed. Based on the engineering background of the 30207 wind tunnel of Mudu Chaideng Mine, the design and application of high-impact toughness anchor (cable) support were carried out from the supporting materials and supporting body structure according to the roadway conditions and environment. From the on-site monitoring results, it can be seen that the deformation of the roadway in the test area has been significantly controlled, and the deformation is mainly based on the deformation of the bottom drum and the two gangs, and the bottom drum volume reaches more than 400mm during the roadway excavation, and the distance of the two gangs reaches 300mm. With the roadway excavation, the force of the roof bolt cable is gradually stabilized, and the force is 170kN and 150kN respectively. The force of the mining help bolt (cable) is quite different, and the axial force of the bolt is gradually lost and gradually stabilized; The force fluctuation of the side bolt of the coal pillar is large, and the force of the anchor cable is relatively small, and the force is located at 70-110 kN. On the whole, the roadway support strength is improved, the stability of the roadway surrounding rock is ensured, and the demonstration effect is good.

Xinjiang open-pit mining area is located in an ecologically fragile area, where the spoil heap soil is subjected to intense human disturbance. The natural and human interference has exacerbated the water shortage, leading to the prominent soil salinization. Water has become the key factor limiting ecological restoration in the arid region of Northwest China. In order to investigate the influence of different application rates of soil amendments on the water retention and holding performance of highly saline-alkaline soil, the surface soil of a dump in an open-pit mining area in Xinjiang was used as the experimental objec,and one-dimensional column infiltration experiments and soil leaching experiments were designed. By adding different concentrations of γ-PGA and humic acid to the soil surface, the study analyzed the changes in soil water retention and holding performance caused by the application of γ-PGA and humic acid, and fitted the measured data to study the suitability of γ-PGA and humic acid for the spoil heap soil in the mining area. γ-PGA can improve the infiltration characteristics of highly saline-alkaline soil. Compared with the blank group, the advancing front velocity of the wetting front was significantly reduced and the cumulative infiltration volume decreased by 3.6%, 4.1%, 2.1% and 4.8% with the combined application of γ-PGA and humic acid. The fitting results of the Philip model and the Kostiakov model show that as the application rate of γ-PGA increases, the influence of γ-PGA on soil water movement parameters becomes increasingly significant. With the increase in the application rate of γ-PGA, the Philip model is more suitable for fitting the modified soil water infiltration in the group of combined application of γ-PGA and humic acid. Compared with the blank group, the soil surface salt ion content was significantly reduced in the combined application of γ-PGA and humic acid; the volume of leaching liquid was reduced by 11.85%, and the soil surface and 10 cm deep water holding capacity were increased by 165% and 133.68%, respectively, with the increase of γ-PGA application rate. The combined application of γ-PGA and humic acid in the saline alkaline soil improved the infiltration characteristics and water distribution of the soil, enhanced the soil's water retention and water holding capacity, and improved its resistance to salinization.

In order to explore the mechanism of coal spontaneous combustion and reduce the risk of coal spontaneous combustion in storage and transportation,a tube furnace was used to simulate the low-temperature oxidation process of coal storage and transportation.The evolution law of pore structure of low-rank coal was analyzed by low-temperature nitrogen adsorption-desorption method.The results indicated that the most of holes of the Santanghu coal was similar to neck bottle and ink bottle. And there were also some cylindrical holes and slit flat holes.The critical pore size of Santanghu coal were around 1.8nm, 6.8nm and 9.3nm. With extending oxidation time, the pore roughness and the volume of mesopore and micropore increased. The percentage of pore volume increase was the largest.The transformation of pore structure of Sandanghu coal was be divided into three stages by oxidation temperature.The specific surface area, mesopore and micropore increased before 80℃. The specific surface area and pore volume continued to increase between 80℃-110℃. The pore volume and specific surface area of Santanghu coal reached the largest at 110℃. The pore volume of micropores increased the most.Comparing with the raw coal, the pore volume of micropores increased by 45.83 percentage points and the specific surface area increased by 61.99 percentage points.The specific surface area , micropores and mesopore decreased between 110℃-170℃.