Abstract: The present invention discloses a multi-energy complementary system for a co-associated abandoned mine and a use method. The multi-energy complementary system for a co-associated abandoned mine includes a mining mechanism, a grouting mechanism and an energy mechanism. In the present invention, the mining of coal and uranium resources is realized through the mining mechanism, the subsidence and seepage reduction of the stratum is realized through the grouting mechanism, and the effective utilization of waste resources is realized through the energy mechanism. Finally, with the efficient cooperation of the three mechanisms, safe and efficient development and utilization of co-associated resources in the full life cycle are realized, and the purposes of green and efficient mining of coal and uranium resources and secondary development of a coal seam goaf are achieved, thereby facilitating the realization of dual-carbon goals and the development of low-carbon green energy.

Abstract: The present disclosure provides a test system and a method for measuring efficiency of underground coal gasification, and relates to the technical field of underground coal gasification, comprising a gasification agent supply system, a gasifier, an outlet and recycling system and a monitoring system, wherein the gasification agent is mainly injected into the gasifier and then chemically reacts with the coal by igniting the gasifier at a high temperature to generate gas, while after the gas passes through the outlet and recycling system, the composition and content are measured, and the monitoring system monitors an operating state of the gasifier, injection of the gasification agent and production of gas, temperature change in the gasification channel and ignition temperature and pressure gauge data.

Abstract: Disclosed is a method for measuring gas pressure of a close-distance seam group simultaneously, including the following steps: constructing a pressure-measuring drill hole inclined downwards; lowering a first seam piezometer tube, lowering a baffle and a polyurethane blocking material after a tube head reaching a lowermost seam; and installing a gas pressure gauge; lowering a second seam piezometer tube, lowering the baffle and the polyurethane blocking material after the tube head reaching a second layer of seam; and installing the gas pressure gauge; lowering a nth seam piezometer tube, lowering the baffle and the polyurethane blocking material after the tube head reaching a nth layer of seam; and installing the gas pressure gauge; injecting a high-water and quick-solidifying material into the drill hole; and connecting the gas pressure gauges through optical fibers, and connecting the gas pressure gauges with a ground control system.

Abstract: An intelligent experimental device for collaborative mining of associated resources includes a signal transmission mechanism, a pressure maintaining mechanism, a feeding mechanism, and a reaction mechanism. The signal transmission mechanism includes a centralized controller, an annunciator, signal receivers, a power supply, a power cord, signal transmitters, and signal sensing valves. The pressure maintaining mechanism includes ambient and axial pressure oil chambers, ambient and axial pressure pumps, ambient and axial pressure liquid distribution tanks, a comprehensive pressure distribution pipe, and hydraulic transmission pipes. The feeding mechanism includes monitoring analyzers, temperature controllers, solution transfer pipes, seepage pumps, mixture conveying pipes, a comprehensive liquid distributor, an aggregate chamber, a liquid chamber, an oil chamber, a gas chamber, a mixing chamber and an analytical purifier.

Abstract: A system for detecting a concentration of free SiO2 in coal dust includes a first sampling tube and a second sampling tube for sampling the coal dust, a three-way control valve communicated with the first sampling tube and the second sampling tube respectively, a photoacoustic spectrometry detection device communicated with the three-way control valve through a connecting pipeline, and a SiO2 reaction tube for reacting SiO2 in the coal dust; and the SiO2 reaction tube is disposed on the second sampling tube. In the present disclosure, a coal dust sampling line is convenient to change by disposing the three-way control valve, and the first sampling tube and the second sampling tube are respectively communicated with the photoacoustic spectrometry detection device, so as to perform a differential accurate detection of the reacted CO content, and to obtain the SiO2 content.

Abstract: Disclosed is a method for measuring gas pressure of a close-distance seam group simultaneously, including the following steps: constructing a pressure-measuring drill hole inclined downwards; lowering a first seam piezometer tube, lowering a baffle and a polyurethane blocking material after a tube head reaching a lowermost seam; and installing a gas pressure gauge; lowering a second seam piezometer tube, lowering the baffle and the polyurethane blocking material after the tube head reaching a second layer of seam; and installing the gas pressure gauge; lowering a nth seam piezometer tube, lowering the baffle and the polyurethane blocking material after the tube head reaching a nth layer of seam; and installing the gas pressure gauge; injecting a high-water and quick-solidifying material into the drill hole; and connecting the gas pressure gauges through optical fibers, and connecting the gas pressure gauges with a ground control system.

Abstract: A gas-liquid spray dust settlement system for a fully mechanized mining face includes an atomization humidification subsystem, a boundary mist curtain subsystem, and a dust mist recycling subsystem that are all arranged outside the fully mechanized mining face, where the boundary mist curtain subsystem includes high-pressure blade nozzles mounted to hydraulic supports. The atomization humidification subsystem includes a spray dust settler mounted to a rocker arm of a coal cutter and configured to spray water mist completely covering the high-pressure blade nozzle. The dust mist recycling subsystem includes a wind-water linkage dust remover mounted to a semi-encircling support base, arranged under the spray dust settler, and configured to collect the water mist sprayed by the spray dust settler.

Abstract: Methods for modifying a recycled fine powder of concrete and uses thereof. A method for modifying a recycled fine powder can include: crushing a collected waste concrete block with a crusher, grinding with a ball mill, and passing through a 100-mesh sieve, to obtain a recycled fine powder with d50 of 13.5 ?m; placing the obtained recycled fine powder in a dry environment at a high temperature, drying, then taking out, and cooling to room temperature; preparing tannic acid solutions with different concentrations, mixing the cooled recycled fine powder with the prepared tannic acid solutions, and continuously stirring by a glass rod.

Abstract: A system for detecting a concentration of free SiO2 in coal dust includes a first sampling tube and a second sampling tube for sampling the coal dust, a three-way control valve communicated with the first sampling tube and the second sampling tube respectively, a photoacoustic spectrometry detection device communicated with the three-way control valve through a connecting pipeline, and a SiO2 reaction tube for reacting SiO2 in the coal dust; and the SiO2 reaction tube is disposed on the second sampling tube. In the present disclosure, a coal dust sampling line is convenient to change by disposing the three-way control valve, and the first sampling tube and the second sampling tube are respectively communicated with the photoacoustic spectrometry detection device, so as to perform a differential accurate detection of the reacted CO content, and to obtain the SiO2 content.

Abstract: The present disclosure relates to a method and system for determining a rational width of a gob-side working face under a condition of thick and hard key strata. The method includes: constructing a piecewise function with a width of a gob-side working face as an independent variable; obtaining values of parameters of the gob-side working face; determining a solution set based on the values of the parameters of the gob-side working face, the piecewise function, and a predetermined function threshold; and determining a numerical value according to the solution set as a rational width and mining the gob-side working face according to the rational width.

Abstract: A preparation method of a cube-like ZnSnO3 composite coated with highly graphitized fine ash comprises steps: S1: with the gasified fine slag of pulverized coal as a raw material, preparing the fine ash by adopting a three-step acidification method; and S2: adding the fine ash prepared in the S1 into a container filled with distilled water, ultrasonically dispersing for 20-40 min, adding equal molar masses of SnCl4·5H2O and (Zn(NO3)·6H2O respectively, uniformly stirring, dropwise adding ammonia into the mixed solution and magnetically stirring until the pH value of the mixed solution is 12, heating the mixed solution, washing the product obtained with deionized water and ethanol for 2-4 times, and finally drying to obtain a ZnSnO3@fine composite. With the dielectric property and conductivity adjusted, the composite prepared reveals a good impedance matching performance and an improved MA performance.

Abstract: Disclosed are a hydro-mechanical coupling experimental device with CT real-time scanning and a use method thereof. The hydro-mechanical coupling experimental device with the CT real-time scanning includes a CT scanning room and further includes a support frame, a hydro-mechanical coupling mechanism and a jack that are arranged in the CT scanning room. The support frame includes a base, a top plate, a plurality of columns for arranging the top plate and the base at intervals, and a movable plate that is arranged between the top plate and the base and can slide on the plurality of columns. The hydro-mechanical coupling mechanism includes an experimental box, a pressure box arranged inside the experimental box and a compression leg slidingly worn on a top of the experimental box; and the experimental box is arranged on the movable plate, and the jack is arranged on the base.

Abstract: Disclosed are a mine dust real-time detection system based on double-photoacoustic spectrometry and a detection method. The mine dust real-time detection system based on double-photoacoustic spectrometry includes a first sampling unit, a first photoacoustic detection cavity, a second sampling unit, a second photoacoustic detection cavity, a signal unit and a processing unit; the first sampling unit is used for sampling in respective, the first photoacoustic detection cavity provides a photoacoustic effect field to substances sampled by the first sampling unit, the second sampling unit is used for sampling in respective, the second photoacoustic detection cavity provides the photoacoustic effect field to substances sampled by the second sampling unit, the signal unit is used for providing a laser signal, and the processing unit is used for collecting and processing a photoacoustic signal.

Abstract: The present invention proposes a coal and gangue separation device, including a first supporting seat, a guide part and multiple material bins. The guide part is hinged with the first supporting seat; the guide part rotates in a vertical direction; and inlets of the plurality of material bins are sequentially distributed on a rotation track of a movable end of the guide part. In the coal and gangue separation device of the present invention, the high-pressure airflow of a high-pressure nozzle does not directly act on the materials, but on grate bar driving mechanisms; and cantilever grate bars are driven to rotate by the grate bar driving mechanisms so as to directionally discharge the mineral aggregate. Therefore, the gangue can accurately enter a gangue collection bin; and the clean coal can accurately enter a clean coal collection bin.

Abstract: Disclosed is a rake-free thickening device including driving area. The device includes a feed assembly, a diversion assembly and a clean coal collection assembly. The clean coal collection assembly includes a driving area. The diversion assembly includes a central tank. Slime water passes through the feed assembly and flows with a medicament from an upper part of the central tank to a middle of the central tank, and then diffuses around. Bubbles carry the fine slime up after reacting. The driving zone drives the dispersed bubbles to a defoaming zone located in the middle of the central tank. The slime water in the central tank flows through the central tank after defoaming. With the continuously filling of slime water, the slime water above the central tank overflows the central tank to the clean coal collection assembly within the diversion and settlement area.

Abstract: A pitch control method and system of a symmetrical-airfoil vertical axis wind turbine collects data by an anemometer, an anemoscope and an angle sensor, outputs an optimum pitch angle based on a control law of a pitch angle and controls the pitch angle to be the optimum pitch angle through a pitch control actuator. In addition to input variables of the control law such as a wind velocity vin and a blade azimuth angle ?, constants such as a rotation radius R, a rotation velocity ? of the blade and aerodynamic coefficients c1, c2 and c3 are also related. A Reynolds number has little influence on three aerodynamic coefficients c1, c2 and c3. The pitch actuator controls the adjustment rods to realize the automatic pitch control of the blades. An expression of the control law of the pitch is concise, the calculation time is short, and a response speed is fast.

Abstract: The present disclosure discloses a method for preparing 2,5-dimethylphenol by selective catalytic conversion of lignin, relates to the technical field of chemistry, and includes the following steps: mixing lignin, a catalyst, and ethanol, and then carrying out a catalytic conversion reaction of lignin under the gaseous supercritical conditions of ethanol; and cooling the reaction product by quenching after the completion of reaction, and then subjecting it to separation and extraction to obtain 2,5-dimethylphenol. The catalyst comprises a modified sepiolite carrier, an active metal Mo, and auxiliary agents Zr and Fe. The process of the present disclosure is simple, and the prepared catalyst is a solid catalyst, which avoids problems of difficult recovery, serious environmental pollution and equipment corrosion caused by the use of homogeneous organic acid-base catalysts.

Abstract: A flocculating, grading, and dewatering device includes a tank body, a mixing zone, a flocculent settling zone, a centrifugal dewatering zone, and a particle screening zone. An initial material is mixed with a chemical agent for a flocculation reaction, a lower sediment material settles and an upper liquid overflows. In the centrifugal dewatering zone, a screen basket is allowed to rotate to facilitate a centrifugal movement of the sediment material, water in the sediment material moves into a guide cavity and then flows to a centrifugate outlet, and then a dewatered material in the screen basket is removed out of the screen basket. In the particle screening zone, a screening mechanism screens particles of different size grades in the dewatered material, and water generated flows downward and is discharged; liquids discharged from the centrifugate outlet and the overflow port are combined, and then discharged through a mixed liquid outlet.

Abstract: A sprayer for settling dust of a coal mine includes: an outer housing, having at least one opening configured to spray water mist; a sprayer, placed in the outer housing, configured to spray water mist through the opening; a plurality of water curtain nozzles, configured to spray water curtain lines outside the opening to block suspended dust; and a support, configured to support the outer housing. The water curtain nozzles are in an equidistant arrangement around a center of the opening. A plurality of the water curtain nozzles are constructed such that the nozzles are all oriented toward the same point, to form a circular or conical water curtain.

Abstract: A device for measuring a flow velocity and a flow direction and geological parameters of groundwater through cross holes of deep wells includes detectors and a device for throwing the tracer source. A method includes measuring a correspondence between a conductivity and a concentration of a tracer solution at different temperatures in a laboratory; selecting at least two boreholes; selecting a target aquifer section; placing the detectors in the target aquifer section in the hole to test a conductivity background value and a temperature value; using the device for throwing the tracer source to place the tracer solution in the hole for throwing the tracer source, and using the detectors to measure a water conductivity and temperature in a detection hole, to obtain a distribution curve of a tracer solution solubility with time; performing cross-test, and calculating the seepage flow velocity and flow direction of groundwater in the hole.