In order to realize the efficient transportation of gangue from ground to underground in solid filling coal mining transportation system, three different ways of gangue transportation are introduced in this paper. Taking the design of vertical gangue throwing system and gangue inclined shaft transportation system as examples, the structure design of gangue transportation system and the calculation of key parameters of gangue throwing well are discussed in detail. Finally, from the point of view of reducing the amount of gangue throwing well at the source. The design method of combined arrangement of coal and gangue separation in underground mine is discussed. Through the systematic design method, the multi-design mode of gangue transportation system is established, which provides a reference for the design of solid filling coal gangue transportation system under similar conditions.

Abstract：Based on the basic geological conditions,roadway construction conditions and auxiliary transportation status of a mine.By analyzing the advantages and disadvantages of trackless auxiliary transport transformation,proposing a scheme of rail auxiliary transportation transform to trackless auxiliary transportation.The scheme is analyzed in detail from the feasibility analysis of trackless transformation,trackless transformation measures，and trackless auxiliary equipment selection and calculation.Finally analyzing the economics of the trackless auxiliary transportation,proving the efficiency of trackless auxiliary transportation.

A heating method using air compressor combined with air source heat pump as heat source is proposed, use to meet the annual hot water demand of coal mine workers. Combined with the calculation and analysis of engineering examples, Explain the feasibility of this technology in theory and practical application. This method can recycle a large amount of waste heat of air compressor, combined with air compressor waste heat recovery system and air source heat pump system, it can replace the heating mode of gas boiler. The payback period of the project is only 2.67years, which is a technology worth promoting.

In view of the change of coal seam occurrence in open pit mining in China, this paper establishes a 3d geological model, optimizes the design of the throwing blasting step based on the theoretical design, and calculates the height of the throwing blasting step corresponding to the thickness of each coal seam. This paper takes heidaigou open-pit coal mine from the first mining area to the second mining area as an example to optimize the design. The occurrence of coal seam changes, the thickness of coal seam increases, and the inclination of coal seam in the direction of working line increases. There is a fault depression zone in the north of the second mining area, which results in a large local change in the height of the throwing blasting step. In the field operation, the throwing blasting step height should not change frequently, and the front and rear amplitude should not change too much. On the premise that the coal exposure is not affected within the one-year period unit (about 4 pieces of advance), the height of throwing blasting steps is linearly balanced, the height of throwing blasting steps is slowly adjusted, and the top slope is adjusted to meet the slope requirements of the cone drilling rig.

Abstract: In order to study the energy-saving characteristics of the mining vibrating screen from the original structure, the information of the design stage of the mine energy-saving two-stage vibrating screen is lacking and can not be quantitatively evaluated. The black box method is used to design the scheme, and the scheme combination model is established. The functional analytic method establishes the optimal solution model of the scheme combination evaluation, and uses the dynamic programming method to find the optimal structural scheme combination of the mine energy-saving two-stage vibrating screen. The scheme design of the energy-saving two-stage vibrating screen is completed according to the optimal solution of the scheme. , digital prototype development and product prototype manufacturing. In order to verify the design feasibility, the prototype was subjected to vibration test. The test results show that the double-stage sieve is 37.8% more energy efficient than the traditional sieve of the same specification, and the design of the scheme is reasonable.

at present, the flexible mould concrete gob side entry retaining wall is only suitable for the application under normal conditions, so as to solve the complex supporting conditions of the gob side entry retaining, such as collapse column, fault and fracture development zone, etc., it can achieve better supporting effect. A mine 3307 fully mechanized top coal caving face as the engineering background, the first coal mine in thick coal seam with flexibleformwork concrete along the left lane and anchor arch process air surface. Mainly through the introduction of the collapse column, fault zone in roadway anchor arch support, grouting technology aided ribside support for gob. The engineering practice shows that the flexible formwork concrete gob and anchor arch process system is simple, the construction speed, roadway support, good sealing effect in complex section. Goaf roadway support strength reached coalproduction along the coal mine 3307 fully mechanized top coal caving face, have economic benefits and good application prospect.

in view of the serious deformation of the heading section of the roadway along the fully mechanized caving face and the difficulty in supporting, the overlying strata fracture structure model of the fully mechanized caving face along the roadway was analyzed theoretically. Combined with the geological conditions of the 090510 working face of the coal mine in the section, the reasonable excavation location of the roadway along the roadway was determined. And the research method of numerical simulation are used to analyze the plastic zone and stress distribution of the 090510 roadway, the main failure characteristics of the track roadway in the over-front section in the mining process have been obtained, and the deformation mechanism of roadway surrounding rock has been studied. Finally, the reinforcement mechanism is put forward, and the scheme of reinforcing the in-front section of the roadway with the reinforcement of anchor cable and the advance hydraulic support is adopted. The field practice shows that the deformation of surrounding rock in advance section is small, which is conducive to realizing high yield and high efficiency and ensuring safe production of working face, and provides a demonstration and reference for advanced support technology of fully mechanized caving face.

In order to study the limiting factors affecting the conversion efficiency of bolt prestress in underground coal mine roadway, six groups of bolt pre-tightening torque and pre-stress conversion tests were carried out in a mine roadway. About the transformation efficiency of anchor prestressing, the greater the deflection angle of anchor installation, the lower the transformation efficiency of anchor prestressing; the strength of coal and rock strata supported by anchor limits the value of anchor prestressing; the higher the strength of coal and rock mass, the greater the value of anchor prestressing. The research results can provide reference for the design of bolt prestress parameters in coal mining roadway.

In response to reduce engineering quantity of gas drainage borehole in coal seam with low permeability, the hydraulic fracturing technology of low permeability coal seam was studied. It put forward overall hydraulic fracturing in mining-coal bed which is based on kilometer directional long hole, developed a high pressure and stable sealing equipment which is suitable for uncorrected drilling in medium-hard and low permeability coal. The hydraulic fracturing effect and influence scope were studied and evaluated by the variations comparison with the coal total moisture and borehole gas parameter during pre and post of hydraulic fracturing. The results showed that The test realized the length of the coal segment of the hole underground for the whole fracturing was up to 300 m，the injected water volume of single hole was 1613 m3， and the maximum injection pressure was up to 24.60MPa. The maximum impact radius of the fracture hole in left working slope is 33m and the right working slope is 38m. The Methane extraction from scalar increased average 12.70 times and the borehole gas drainage quantity of hectometre increased average 2.67 times which are Compared with the non fracturing data. The research results improve gas drainage rate and guarantee mine excavation replacement efficiency, provide a reference support for the whole hydraulic fracturing and highly efficient gas drainage in the similar geological conditions.

Abstract: In order to solve the problem of equivalent spray thickness of dry and wet shotcrete and provide a reference for wet shotcrete design, the relationship between the outer radius of the sprayed layer and the strength of the shotcrete are built under the same support strength on the basis of the Lame solution of the elastic mechanical cylinder. And combined with laboratory test and a engineering example for calculation.The results show that the strength of shotcrete is negatively correlated with the outer radius of the sprayed layer under the same support strength.Using wet shotcrete can reduce suitable spray thickness.

In order to solve the problems of slow moving speed, unbalanced force between front and rear pillars, and poor adaptability to electro-hydraulic control system in the process of using ZF10000/23/37 four-pillar support and shield caving support in 4107 fully mechanized coal face, the characteristics of two-pillar shield caving hydraulic support are studied, and according to coal seam geology in mine. Under the condition and mining technology, ZFY12000/23/40D two-pillar shielded low-level caving support is selected in 4108 fully mechanized caving face. The adaptability of two-pillar caving support in 4108 fully mechanized caving face is better than that of four-pillar caving support in terms of working face moving time, caving time, resource recovery rate, support safety valve opening rate, support overhaul and support sheet side condition.

In order to solve the problem of rib spalling in the high caving face of soft coal seam, take the high caving face of No. 3 coal seam in Sanyuan Zhongneng Coal Industry as an example. Based on the method of rib spalling observation, laboratory test, site condition survey, PASAT high stress area detection, etc. The main geological factors and mining technical factors affecting the rib spalling were obtained. Based on the reasons of rib spalling, the risk area is divided into four categories: which are high-stress rib spalling risk area, geological structure rib spalling risk area, strong weighting rib spalling risk area, overhand mining rib spalling risk area. From the purpose of reducing the pre-disturbance and improving the self-bearing capacity of the coal wall, the technical measures for optimizing the mining parameters, improving the support conditions and optimizing the shifting mode are proposed for different risk types. The results show that after using the spalling prevention measures, the spalling area and depth were obviously reduced, and the working environment of the working face was improved. It can provide reference for the similar working conditions and surrounding mines.

Fore to the 9-10-2218 working face when finishing equipment cannot routinely retracement, and close to instability of coal seam roof, from the face began to surf the Internet to the final device retracement, rewind support scheme was proposed, and a retreat channel anchor net + anchor combined support and "the anchor section no timber supporting" process, optimization of construction parameters, innovation to implement the nose triangle preconditions such as complete sets of technology. The results show that the technology of the reversing equipment is reasonable, the combined support of the retracting passage and the construction parameters of the wiping Angle can meet the requirements of the retracting equipment, save time and materials for the pressure relief roadway and ensure the safe and rapid recovery of the working face, which can provide a reference for the retracting of the same type of working face.

The development of karst collapse columns is concealed, and the mine water damage caused by it is extremely destructive, directly jeopardizing the safe production of mines. The paper takes the karst collapse column of the Fangezhuang Minefield in Kailuan as the research object. Based on field survey, mining production data and borehole data, the development characteristics of karst collapse columns in the study area are studied. Moreover, the main controlling factors of the development of the collapse column are systematically analyzed from the aspects of geological background, structure conditions, material conditions and hydrological conditions. The research shows that the formation of the collapse column is diverse. The cross section generally has a size of a cylinder or a cone, the long axis diameter is between 39-115 m, and the short axis diameter is between 29-70 m. The karst collapse column in the study area is distributed in the structurally complex fold zone, which is obviously controlled by the structure, and is closely related to the small faults of the surrounding rock and the annular fault and joint development. The long-term weathering and erosion of the top of the Ordovician limestone has provided a material basis for the extensive development of karst. Furthermore, Groundwater dynamic conditions in the study area have obvious effects on the development scale and distribution of the collapse column.

To study the mechanism of bolt support and control the stability of roadway surrounding rock, firstly, based on the bolt reinforcement effect, the support effect of the bolt is considered as the volume force acting on the surrounding rock of the anchorage zone, and the reinforcement effect of the anchor is regarded as enhancing the strength parameters of the surrounding rock of the anchorage zone. Then, the roadway calculation model is established, and the elastic-plastic analysis is carried out, and the analytical solution of the surrounding rock stress and displacement of the roadway is derived. Finally, combined with the example, the calculated value is compared with the measured value, and the surrounding rock stresses of bolt support and unsupported are compared, meanwhile the influence parameters of surrounding rock deformation are analyzed. The results show that the bolt support improves the stress state of the surrounding rock in the plastic zone and improves the self-bearing capacity of the surrounding rock; The parameter design of bolt length and spacing follows the principle of “Long and thin, Short and thick”. The analytical solution of the theory considers the blot reinforcement effect, provides a theoretical reference for understanding the bolt support mechanism, and can also provide a reasonable bolt support scheme for the surrounding rock control of the roadway.

Based on the engineering background of mining prone ground pressure accidents which are easily induced by the mining face of adjacent faults, the mechanical model and calculation analysis are established in this paper. The results show that the working face mining can affect the weak surface of the fault, and can be divided into the far field and the near field disturbance effect according to the distance, and the fault structure is activated by the far field mining. The failure form of the adhesive contact points on the weak surface determines whether the weak surface of the fault is sliding state or stick slip state. When the fault structure is activated by the near field mining, the mining face is located in the footwall layer of the fault, and the fault rock mass is shear slide upward and downward, and the risk of the fault rock block tensioning separation is higher than that of the upper plate mining method.

In order to study the factors of gas combustion (explosion) in goaf induced by hard and thick sandstone roof containing pyrite, the goaf of 121109 working face in Xinji No.2 Coal Mine was studied by means of field monitoring, laboratory test and theoretical analysis. The results show that the roof sandstone of 11-2 Coal seam is grey-white, fine-grained structure, massive structure, and the content of CaO and Fe2O3 is high. According to the calculation formula of the collision velocity of roof sandstone collapse collision, the theoretical value of the interval of the collision velocity of roof sandstone collapse is 2.78~8.31 m/s and the coefficient of affluence is 3.34~9.97 m/s, and the continuous spark will occur when the sandstone roof rubs at very low velocity (the test contact line velocity is 0.3 m/s), and under the same contact friction condition, yellow iron will be produced. It is easier for ore cores to produce continuous sparks, and the spark intensity is higher than that of pure sandstone cores.

Spontaneous combustion in gob is a complex process and studying on the variation and influence factors of airflow field and oxygen concentration field is the prerequisite to forecast high temperature in gob. Firstly, the mathematical model of flow field and oxygen concentration field under moving coordinates is established, and then the dimensionless form of the model is studied. At the same time dimensionless criteria such as dimensionless pressure, dimensionless velocity, dimensionless oxygen diffusion coefficient, and dimensionless oxygen consumption velocity coefficient are defined. Through analysis, residual coal thickness is an important factor of spontaneous combustion in gob. Finally, the distribution map of the oxygen concentration field under different thickness of the residual coal is obtained by numerical simulation, concluding that the distribution of oxygen in the goaf is wider with the thickness of the residual coal is decrease.

Aiming at the difficult problem of gas prevention and control in the mining of close-range outburst dangerous coal seams in Shaqu Coal Mine, the stress distribution characteristics, pressure relief range and drilling gas drainage arrangement of the floor in the downward mining of close-range coal seams are analyzed by means of laboratory test and numerical simulation field test. The results show that: (1) The physical and mechanical properties of the roof and floor strata of coal seam group are uneven distribution, which shows that the horizontal properties of the strata are similar, and the vertical lithologic differences are large. Among them, the roof and floor of No. 3, No. 4 and No. 5 coal seams are sandstones with high density, cohesion, tensile and compressive strength. (2) After the No. 4 coal seam is mined, the obvious vertical stress of the middle floor strata in the goaf is 0MPa in a certain range, the high floor extraction roadway is within the pressure relief zone, and the vertical stress of the surrounding rock of the bottom extraction roadway in the middle and lower part of the goaf is less than 5 MPa. It is suitable to arrange the floor high extraction roadway at 14m away from No. 5 coal bed. (3) Engineering practice shows that After half a year of gas extraction, the gas pressure dropped from 1.5 MPa to 0.2 MPa, and the daily gas extraction rate maintained above 80%. The bottom drainage roadway has better gas extraction effect..

The influencing factors of sealing effect were reviewed, the stress around borehole and the initiative support sealing technology were analysed based on fluid-solid coupling leakage channel model of hole drilled along seam. The results showed: drilling went through “three zones” of in front of roadway, fracture further developed in stress concentration zone; the effect of two disturbances decreased with increase of distance from borehole wall, the superimposed effect of relaxation zone of borehole and roadway appeared local area around borehole, and here the leakage channel formed; without support force, the drainage negative pressure communicated atmosphere easily with in a short time through fracture of borehole and roadway pressure relief, and leakage channel was established; the coal around borehole was reinforced, the relief fracture was healed, leakage channel decreased and the effective drainage time increased with support force, and the effect was more obvious with increase of support force. Further, the initiative support sealing technology was tested, and the results showed: daily average drainage concentration and daily average drainage purity of single hole was nearly 3 times and 1.6 times higher than ordinary capsular bag sealing, and theoretical analysis results were verified.

Gas leak on the surface of a village.Due to the production of coal mines near the village, the surface leakage of gas comes from the possibility of mining coal seam.In order to confirm the source of gas,analyze the causes of gas leakage,so as to take effective measures,Sampling experiment of correlation between surface leakage gas and underground goaf gas and analysis of influence of coal mining on groundwater are carried out.The results show that the source of surface leakage gas is not coal seam gas of coal mine.However,due to the perennial mining of the coal mine and the drainage of a large number of shallow water during the construction of the South air shaft in the mine, the water level in the region has been lowered, resulting in the leakage of shallow gas to the ground.It can provide reference for the cause analysis of surface gas leakage under similar conditions.

In order to weaken the hard roof, reduce the severity of the roof pressure, and ensure the safety of the mining process, the method of blasting and crushing is used to artificially destroy the integrity of the roof. The peak value of the vibration velocity generated by the blasting is calculated by the first theoretical calculation. Then the numerical simulation software ansys/ls-dyna is used to establish the physical model to simulate the whole process of the roof blasting and blasting, and the vibration of all the blasting observation points is extracted. The peak value and the theoretical calculation value are comprehensively analyzed and compared, and combined with the blasting vibration safety allowable standard value, the peak vibration velocity from the nearest measurement point of the residential area does not exceed the safety allowable value, and the conclusion of the safety of the neighboring Feng villagers is not affected. Furthermore, combined with engineering experience, the final conclusion that the blasting operation according to the designed roof pre-split blasting scheme will not have a significant impact on the safety of Shangfeng villagers' residence is obtained.

Kailuan mining area is the main coal production base in Hebei Province. The coal-bearing strata of Carboniferous Permian formation are abundant in the mining area. In order to explore the occurrence characteristics of No.14 coal in Kailuan mining area, this paper analyzed the original sedimentary environment and coal seam occurrence characteristics of Kailuan mining area by statistical analysis of seeing No.14 coal boreholes in Kailuan mining area, using sedimentary stratigraphy, coalfield geology and coal petrology. It is concluded that the occurrence characteristics of No.14 coal are mainly influenced by the original sedimentary environment. In the early stage, the main sedimentary environment is the Lagoon facies. Because of the existence of subaqueous bar, the hydrodynamic force in the Lagoon is weak, and peat is deposited earlier on the land side of the sand bars. Due to the continuous advance of land to the sea, the study area gradually transited to tidal flat facies and exposed to the surface, which resulted in extensive sedimentary peat in the study area. Later, the peat accumulation was stopped due to the transition from transgression to shallow sea facies.

Aiming at the problem of insufficient power and insufficient fuel in the operation of existing mine explosion-proof rubber tire vehicles in the roadway, a combination of dynamic theory model and test method is proposed to analyze the optimal power, fuel consumption and energy efficiency. Firstly, the engine parameters were selected according to the actual working conditions. Then the linear regression method in MATLAB software was used to obtain the optimal fourth-order fitting curve equation, and the mathematical model of the engine was established. Based on the engine model, the dynamic system model of the explosion-proof rubber tire vehicle was built and the grade, acceleration and economy were analyzed. Finally, a dynamic test was carried out, and the universal characteristic curve obtained by the experiment was compared with the simulation. The test results show that the engine speed is 1800r/min, which is the best economic area and the best power area. The minimum fuel consumption is 222g/kWh. The mathematical model of the engine and the rubber wheel vehicle power system model are accurate. It laid the foundation for subsequent engine research and vehicle power matching.

Climate change caused by greenhouse gas emissions has attracted more and more global attention. Open-pit mining, as an important way of coal mining, has the characteristics of high energy consumption and high greenhouse gas emissions. Carbon emission accounting in open-pit coal mines can provide a clear understanding of the source of carbon emissions and provide data support for energy saving and emission reduction in open-pit coal mines. In this paper, the open pit coal mine is taken as the research object, and the greenhouse gas accounting model is constructed on the basis of identifying its emission sources. Then based on the energy consumption of Haerwusu Open-pit Coal Mine, the calculation and analysis of greenhouse gas emissions were carried out. At last, according to the characteristics of open-pit coal mine, the policy suggestions for its emission reduction strategies are given.

In order to study the effect of gate’s angle on the pressure of vibrating feeder’s surface, in this paper, the feeding process of LDDF2330 vibrating feeder is simulated using EDEM, and parameters of gate’s angle is set to 80,70,60 and 50 degree at a constant of gate’s opening, respectively. The pressure of vibrating feeder’s surface was obtained and analysed for different gate’s opening with the same position and for different position with the same gate’s opening, respectively. Results show that the decrease of the gate’s angle results in the pressure of feeder vibrating bed surface decreases linearly and the position of the maximum pressure moves to the end of the vibrating feeder, respectively.

Taking Yanzishan slime as the research object, industrial analysis, elemental analysis and ash fusion analysis were carried out. The combustion characteristics of coal slime and CO2 atmosphere gasification characteristics were analyzed by TG-DTG-DSC. The rheology of coal water slurry were tested with naphthalene sulfonic acid sodium formaldehyde as the dispersant. The results showed that, at hearting rate of 10, the ignition temperature of the slime is 456 °C in O2 atmosphere and the depolymerization temperature is 355 °C in CO2 atmosphere; the slime could be prepared to a high concentration of coal water slurry when the concetration could reach to 72.01% at optimized dispersant dosage of 1.2%, and the slurry presented shearing thining characteristic. Considering the low sulfur content and high ash content, the slime could be used as a blending material for combusting and gasifying coal water slurry preparation to realize efficient and green utilization.

Coking coal is one of the important raw materials of iron and steel industry, which guarantees the development of China's iron and steel industry. Research on coking coal supply and demand has important guiding significance for the development of China's iron and steel industry. This paper studies the present situation of coking coal supply and demand, the output change and the structure of coal types in China, analyses the development potential of coking coal in major coking coal producing provinces, analyses the influence of structural reform on coking coal supply on supply side, and comprehensively considers various factors such as coking coal resource reserves, output changes and remaining service life in each province and region, the medium and long term supply of coking coal in China is forecasted. The demand of crude steel and pig iron in medium and long term is forecasted by steel consumption coefficient method of GDP, and the demand of coking coal in medium and long term is forecasted based on steel consumption demand. According to the forecast and analysis, the supply and demand of coking coal in the medium and long term in China will show a marked downward trend; from the point of view of coal classification, the supply and demand gap of coking coal and fertilizer coal in the medium and long term in China is large, and it is urgent to strengthen the protective exploitation and utilization of domestic coking coal resources.

According to the crane lift device problems of the chain length can't be adjusted and the hydraulic support rocked wildly in lifting and crane break easily, a new device scheme use chain wheel to replace crane is proposed. This paper research the meshing behavior of chain wheel used to lift device and adaptability of half chain wheel used to heavy lifting. The processing technology and the method of calibration about chain wheel is given, also optimized the parameters of lift mechanism, the new chain wheel lift device has been applied well in practice.

Abstract: Based on the virtual prototyping technology, the multi-body dynamics analysis of a certain type of battery bracket carrier vehicle was carried out, and the full-load flat road and full-load climbing 10 were obtained. Kinematics and dynamics parameters of slope and full-load low-speed road through 100 mm trench under three typical working conditions and the stress state of each component. Based on the worst simulation results of the third trench road condition, the strength of the whole frame is analyzed in the finite element software, and the defective parts of the front, middle and rear frame are found out. The stress concentration is reduced by increasing the structural stiffener plate, reducing the thickness of the plate and opening the weight reducing hole. The structural strength of the rack is improved, and the total weight loss of the three racks is 22% under the premise of meeting the service requirements and allowable stress of the materials. After more than one year of industrial test in coal mine, the frame strength fully meets the requirements of field use, which provides a reference for dynamic analysis and structural optimization design of similar vehicles

In order to reduce the labor intensity of small (light) truck when loading bulk materials, a small loader with foldable hopper was designed. The overall design scheme is：The hopper is open in heavy section and has the largest loading capacity and the hopper is folded in the return section, which effectively saves the space under the frame and reduces the height of the machine. The physical and mathematical models of hopper are set up. The optimum angle of the frame and the hopper opening angle is determined 60° by using MATLAB, so that the loading capacity of the machine reaches at least 12.5m3/h .The shape and position parameters of the guideway are designed to ensure the opening and folding of the hopper. The trajectory of the hopper in the loading section is simulated by Pro/E. The simulation results show that the hopper can automatically load during the process from folding to opening.

In order to ensure the safe operation of the multi-ropes friction hoist, the diameter of the rope groove should be the same. A frictional lifter drum rope groove parameter detector based on laser ranging is proposed. Firstly, the measuring instrument measures the analog signal of the rope groove radius through the laser sensor. Then, the analog signal is converted into a digital signal that single chip microcomputer can process through A/D conversion. After data reading and processing, the measured results are displayed in real time by the DWIN LCD screen, and the radius changes of the rope grooves are graphically displayed. The drum rope groove parameter measuring instrument can accurately measure the radius of the rope groove and accurately display the measurement result, so that the operator can know the working condition of the drum in time and ensure the safety of transportation promotion.

Abstract: The relationship between carbon emissions and economic growth in major countries of the world is studied with carbon emission Tapio decoupling elastic decomposition model. The characteristics of decoupling at different stages and the evolution of major drivers are discussed. The results indicate that carbon emissions and GDP decoupling of China are generally weak decoupling. Since 2014, China’s carbon emissions have experienced negative growth, and the decoupling state has been strongly decoupled. The overall decoupling state of the US is ideally weak decoupling. The US carbon emissions achieved negative growth, and carbon emissions were strongly decoupled from GDP after 2006 due to the optimization and upgrading of energy structure. The decoupling state in India is worse and Japan's decoupling state is weakly decoupled. Research of driving factors indicate that energy intensity and economic growth effects are the main factors affecting the decoupling of carbon emissions from GDP in China, the United States, India and Japan. In addition, India's carbon emissions are also greatly affected by the population effect, and the energy structure effect has a greater impact on Japan's carbon emissions and GDP decoupling.

Based on the relevant laws, regulations and standards of mineral resources development and utilization scheme, combining with my nine years of experience in nearly three hundred development and utilization plans review, the main points and problems of compiling the mineral resources development and utilization plan are summarized, then take coal resources as an example, the existing problems of nine aspects including plan publish, project overview, mineral commodity supply and demand status and prediction, resources situation, the development scheme, ore dressing and tailings facilities, safety, environment protection and scheme are briefly discussed, according to this, the matters needing attention, improvement measures and suggestions in the preparation of the plan has been put forward, which provides a reference for improving the preparation of the plan for the exploitation and utilization of mineral resources.