Abstract: Disclosed is a system and a method of transient electromagnetic advanced detection. The system includes a detection host, an electromagnetic signal transmitter, a probe, and a communication device. The system and method of transient electromagnetic advance detection disclosed by examples of the present disclosure can realize an early-warning through a transient electromagnetic advance detection in a borehole while drilling the borehole in a tunnel or a roadway.

Abstract: The present invention discloses a vehicle-mounted large-flow fire-fighting foam fluid mixing system, including a supply kit, a mixing kit, a control kit, and a pipeline kit. The supply kit includes an auxiliary gas supply device, a fire pump, an integrated foam pump, a fire pump main motor, and a coupling. The mixing kit includes a fire monitor interface, a foam generating device, and a fluid mixing device. The control kit includes a foam mixing proportion single-chip microcomputer control system, an alarm module, a power module, an auxiliary air compressor switch module, a frequency converter, and a central control display screen. The pipeline kit includes an air drainage tube, a fire hose, a foam liquid pipe, and a pipeline valve. For the problems of flow fluctuation and low foam foaming efficiency, the present invention optimizes the design and adopts a new control policy, thereby implementing precise mixing under the large-flow condition.

Abstract: The present disclosure provides a method for extracting and recovering gold from an aqueous solution, the method including: (1) gold extraction from an aqueous solution through electrocoagulation, in which an electrocoagulation reaction is performed in an electrolytic cell to produce iron hydroxide in-situ, so as to capture gold in the aqueous solution and reduces the gold into gold nanoparticles in-situ; (2) pickling and liquefaction of the precipitated iron sludge, in which the obtained precipitate is dissolved in nitric acid to dissolve iron flocs after washing treatment; and (3) separation and recovery of gold through a nanofiltration membrane system, in which the resulting solution after pickling the precipitated iron sludge is subjected to cut-off treatment using a nanofiltration membrane to separate nano-sized elemental gold from the solution, and then the resultant is washed with water to obtain elemental gold.

Abstract: A method for improving a monitoring capability of a borehole-surface micro-seismic monitoring system includes selecting multiple candidate points for installing surface wireless sensors to form a natural-number-coded candidate point set and combining a fixed number of candidate points randomly selected from the candidate point set with an underground installed sensor set to form a borehole-surface micro-seismic monitoring network; carrying out multiple random selections until a certain scale of borehole-surface micro-seismic monitoring network deployment plans are generated; establishing an evaluation model for a monitoring capability of each borehole-surface micro-seismic monitoring network deployment plan according to a propagation relation equation between a micro-seismic energy and a first-arrival peak amplitude of a P-wave, forming an initial population; determining an optimal borehole-surface micro-seismic monitoring network deployment plan through a genetic algorithm; and determining an optimal surface

Abstract: An underground mining method for unexploited coal in a boundary open-pit mine is provided. A shaft construction platform is arranged at one rock step to two rock steps above a coal seam. Intermediate bridges are built starting from a pit bottom. Mining area clay is laid on a working slope where no intermediate bridge is built and on a side slope with an outcrop of the coal seam as a sealing layer to seal the slopes. Auxiliary vertical shafts and main inclined shafts are dug. The pit bottom is dug downward to form a digging space on a side close to the working slope between two adjacent ones of the intermediate bridges, and clay is filled into the digging space to form an artificial water barrier layer. A roadway communicating the main inclined shafts and the auxiliary vertical shafts is constructed, and a coal seam stope face is arranged.

Abstract: The present disclosure provides a system for monitoring a scraper chain based on a measurement on transmittance of a torsion spring and a method thereof. The system includes a sprocket-wheel torsion detection device, a fixing device, a wireless receiver, an A/D converter and an industrial computer. In the method, the relative torsion of the two sprocket wheels is converted into the density change of the torsion spring, the light transmission area is converted into the current value by the laser sensing panel, a varying range of the torsion spring is calculated by the industrial computer through the preset threshold and its own program to monitor the operating conditions of the chain. The method has a novel concept, a stable and reliable system, and a high promotion value.

Abstract: Disclosed are a testing system and method under fluid-solid coupling effects. A dynamic stress field during fluid flow, deformation of a porous rock framework, real-time evolution of the stress field and deformation of a fluid-solid interface under fluid-solid coupling effects can be obtained, on the basis of a collected photo-elastic stripe image and a surface deformation image. A stress field of a solid framework and fluid in porous rock, and a strain field of the solid framework and the fluid-solid interface under fluid-solid coupling effects can be visually and quantitatively displayed by means of a display device.

Abstract: The present application relates to an attitude self-correcting underground transportation apparatus based on UWB technology and a control method thereof. A transport clamping and fastening mechanism is mounted on an upper surface of an upper platform part of a six-degree-of-freedom motion platform. An attitude perception and sensing set at least includes three UWB tags, the UWB tags in the attitude perception and sensing set being evenly distributed on the side of the upper platform part of the six-degree-of-freedom motion platform. A control module is configured to send an electric signal to drive the six-degree-of-freedom motion platform and the transport clamping and fastening mechanism to grip an object to be transported, collect positioning information of the attitude perception and sensing set, calculate the attitude of the six-degree-of-freedom motion platform in real time, and perform attitude adjustment with reference to an expected position and attitude to maintain a smooth transportation process.

Abstract: The present disclosure belongs to the technical field of mining equipment, and in particular related to an automatic driving system of a monorail hoist driven based on a digital twin and a method thereof. The system includes a railroad switch sensor module, a positioning system module, a data transferring system, an intelligent control system, a digital twin system and an automatic driving module. The railroad switch sensor module is configured to sense the connection-position state of a movable track in a monorail hoist railroad switch track. The data transferring system is configured to transmit the data on the surface and underground. A bidirectional transmission is performed between the intelligent control system and the railroad switch sensor module, a bidirectional transmission is performed between the intelligent control system and the positioning system module, and a bidirectional transmission is performed between the digital twin system and the intelligent control system.

Abstract: The present invention discloses a method for constructing inner dump type strip mine pit bottom reservoirs section by section, specifically including the following steps: S1: processing end slopes: discarding clay at a lowest step of an inner waste dump of a strip mine; S2: discharging concrete to slope faces of lowest steps of the end slopes on two sides of a pit bottom; S3: sealing the bottom; S4: discarding gravel into a pit of the strip mine; S5: laying geotextile; S6: re-adopting clay on the lowest steps of the end slopes of the inner waste dump, so as to form a reservoir sealing isolation layer; S7: constructing a plurality of reservoirs step by step in an advancing direction of the strip mine; S8: storing water resources: completing installation of water storage wells; S9: completing installation of water fetching wells; S10: storing water resources.

Abstract: A method for blocking mine water inrush includes: grouting first slurry into an interface between the quaternary aquifer and the weathered bedrock aquifer in a fracture grouting manner until a first preset condition is met; forming a first water-resisting cushion after the first slurry is solidified; drilling a curve branch drill hole in the surface horizon downward; grouting second slurry into the curve branch drill hole in a downward grouting manner until a second preset condition is met; forming a second water-resisting cushion after the second slurry is solidified; grouting third slurry onto a top of the first water-resisting cushion in an upward grouting manner until a third preset condition is met; forming a third water-resisting cushion after the third slurry is solidified; wherein the third water-resisting cushion is located on the top of the first water-resisting cushion.

Abstract: Disclosed is a characterization method of closed pores and connectivity of coal measure composite reservoirs, including collecting samples of coal seams and shales reservoirs, carrying out low-field NMR experiments and NMR freeze-thaw experiments on plunger samples and crushed samples with different particle sizes to obtain cumulative pore volume distribution and differential pore size distribution of the crushed samples, comparing crushed samples with plunger samples for optimal crushed particle sizes, and preliminarily determining a distribution range of closed pores; carrying out SAXS experiments on crushed samples to obtain size distribution and volume of total pores of 1-100 nanometers; calculating pore volume of total pores and closed pore volume in composite reservoirs by low-field NMR experiments results; carrying out non-steady overburden permeability experiments and variable factors on plunger samples of coal seams, shales and tight sandstone to characterize the connectivity under influence of pores

Abstract: Disclosed are a grouting material for modifying mudstone, a preparation method and an application thereof, belonging to the technical field of material science and geotechnical engineering. The grouting material for modifying mudstone includes the following raw materials: cement, water, superfine micronized powder, water reducer, silane, fiber, diatomite, urea-formaldehyde resin and waterborne polyurethane. The preparation method of the grouting material for modifying mudstone includes steps of: (1) weighing the raw materials in parts by weight, mixing water of 40% of a total amount of water with water reducer, superfine micronized powder, fiber and diatomite, stirring to obtain a material A; (2) adding silane, urea-formaldehyde resin, waterborne polyurethane and residual water into the material A, obtaining a material B after continuous stirring; and (3) adding cement into the material B, and uniformly stirring to obtain the grouting material for modifying mudstone.

Abstract: The present disclosure discloses a low-energy-consumption grading and positioning method and system for a coal mine auxiliary transportation vehicle, which belongs to the technical field of mine tunnel transportation.

Abstract: An apparatus includes a current excitation source, a roadheader telescopic protection cylinder, an electric rotating apparatus, auxiliary cutting teeth, a cutting head entity, a transmission shaft, an optical fiber ring protective housing, an optical fiber ring, an optical fiber current sensor control unit and a recovery electrode. The apparatus transmits an auxiliary current Ie and a monitoring current Id to a coal seam. The auxiliary current Ie and the monitoring current Id are homologous currents that are incompatible, and the auxiliary current Ie squeezes the monitoring current Id, so the monitoring current Id monitors the environment of the coal seam. The monitoring current Id flows to the coal seam as, and a return current If flows through the transmission shaft and a roadheader expansion part. The optical fiber ring measures the return current If, when the roadheader is heading forward and encounters abnormal geological bodies.

Abstract: A directional drilling-exploring-monitoring integrated method for guaranteeing safety of an underwater shield tunnel includes: drilling a small-diameter borehole below a water area, and establishing an initial geological model; reaming the small-diameter borehole into a large-diameter borehole, placing a parallel electrical method (PEM) power cable and a monitoring optical fiber cable into the large-diameter borehole, acquiring zero field data, primary field data and secondary field data through carbon rod measurement electrodes before tunnel excavation, and processing the data with an existing inversion method to form an inversion image, thereby obtaining a refined geological model of a stratum; starting the tunnel excavation, and respectively acquiring a disturbance condition of rock and soil and a sedimentation and deformation condition of rock and soil around the tunnel during the excavation, thereby implementing safety excavation of the tunnel; and continuously monitoring the tunnel and the surrounding r

Abstract: A gear-track-detachable driving device in a monorail crane for a steep slope includes a driving mechanism, a traveling mechanism, a four-bar linkage mechanism, a connection mechanism, a meshing track plate and transition track plates. The driving mechanism includes driving motors, meshing gears, a bearing rod, and a bearing plate. The traveling mechanism includes traveling wheels, clamping wheels, a shell and telescopic struts. The linkage mechanism includes first and second rockers, a linkage, and a cylinder. The connection mechanism includes fixation plates, a connection plate and connection bolts. When the crane travels to the slope front, the cylinder drives the linkage mechanism to send the meshing gears onto the transition track and adjusts the linkage mechanism into a dead point state, and the telescopic struts are locked. After the crane enters the slope, the meshing gears cooperate with the meshing track plate to provide an auxiliary drive for the crane.

Abstract: The present invention relates to a ground double-hole combined water inrush prevention method for overlying strata movement monitoring and bed separation water drainage. By arranging a rock strata movement monitoring borehole and a bed separation water drainage borehole, interior movement information of an overlying stratum and bed separation generation timing fed back by strata movement monitoring performed inside are monitored; work on the bed separation water drainage borehole is guided by monitoring changes in arranged monitoring points; and through combination of the movement monitoring borehole and the bed separation water drainage borehole, the utilization rate of the bed separation water drainage borehole is effectively increased.

Abstract: The present disclosure discloses an intelligent position sensing system based on spatial three-dimensional model image matching, which realizes three-dimensional precise positioning and target orientation positioning of closed spaces, such as a coal mine. The position sensing system includes a three-dimensional GIS server, a position matching server, a wireless camera, and a wireless access device. Position sensing is realized by comparing an image collected by the wireless camera with a two-dimensional image generated by rendering.

Abstract: The present invention provides a fly ash-based environmentally-friendly hydrogel with a high water retention for preventing and controlling spontaneous combustion of coal in a mine and a preparation method thereof. The hydrogel includes the following raw materials in the following weight percentages: 10% to 30% of a gel-forming material A, 20% to 45% of a crosslinking material B, and water as a balance, where the gel-forming material A is prepared by physical blending of a biodegradable superabsorbent resin, anionic polyacrylamide, a sesbania gum, and fly ash in a weight ratio of (1-3):(0.5-1):(0.5-1):(95-98); and the crosslinking material B is prepared by subjecting zeolite, expandable graphite, and an aluminum citrate complex in a weight ratio of (60-78):(20-36):(2-4) to mixing, dispersing, adsorbing, and freeze-drying.