Abstract: A fly ash-based fire-prevention and extinguishing material with carbon dioxide mineralized and stored, and a preparation method thereof are provided. The preparation method includes: separately weighing 100 parts to 120 parts of water, 1 part to 3 parts of a solid strong alkali, and 20 parts to 40 parts of a fly ash as raw materials, pouring the raw materials into a reactor successively to obtain a resulting mixture, and stirring the resulting mixture at a high rotational speed; adding 10 parts to 20 parts of a solubilizing agent to the reactor, sealing the reactor, introducing carbon dioxide to the reactor at room temperature to maintain a carbon dioxide pressure to obtain a resulting slurry, and stirring the resulting slurry at a high rotational speed; and further introducing carbon dioxide into the reactor to increase the carbon dioxide pressure, and stirring the resulting slurry at a low rotational speed.

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.

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.

Abstract: The disclosure claims a magnetizing device and method for preparing magnetized water for dust fall of an underground coal mine. The device is formed by a plurality of magnetic drums in a parallel connection with connecting elbows in a “U”-shaped arrangement manner. Each magnetic drum consists of an external magnet, an internal magnet, a hollow pressure pipe, a spiral blade, a screen magnet cover, a connecting steel column, a pressure pipe, a closed nut and a flange plate. According to the disclosure, the internal and external magnets are arranged on a spiral flow channel consisting of the hollow pressure pipe, the spiral blade and the pressure blade by means of an alternating arrangement, thereby building an efficient magnetization environment combined by pulse cutting magnetization and spiral turbulence, enabling that the water for dust fall flowing through is magnetized continuously and efficiently.

Abstract: A preserved-amplitude RTM-based FWI method is used to obtain an image of an explored subsurface formation. Model data corresponding to detected data is generated using a velocity model of the formation. Residuals representing differences between the modeled data and the detected data are back-propagated to then update the velocity model a local optimization based on a deconvolution formula employing a backward propagating wavefield and a forward propagating wavefield. Geophysical features of the formation are imaged based on the updated velocity model.

Abstract: Disclosed is a physical-chemical composite inhibitor for controlling spontaneous combustion of low-rank coal, and methods of preparing and using the same. The composite inhibitor consists of a chelate and attapulgite, the chelate is generated by chelation of proanthocyanidin with calcium chloride. The composite inhibitor has moisture-absorbing and moisture-retaining effect, and can reduce water dissipation at low temperature. A stable oxide insulating layer such as MgO and Al2O3 insulating layer can be formed at high temperature, which can block a coal body from contacting with oxygen. In addition, the composite inhibitor can capture hydroxyl free radicals generated during the chain-cycle reaction and destroy peroxide free radicals, and can also interact with an active moiety in coal to form a stable structure such as ether linkage and hydrogen bonding, thereby achieving permanent inhibition of low-rank coal.

Abstract: Disclosed is a physical-chemical composite inhibitor for controlling spontaneous combustion of low-rank coal, and methods of preparing and using the same. The composite inhibitor consists of a chelate and attapulgite, the chelate is generated by chelation of proanthocyanidin with calcium chloride. The composite inhibitor has moisture-absorbing and moisture-retaining effect, and can reduce water dissipation at low temperature. A stable oxide insulating layer such as MgO and Al2O3 insulating layer can be formed at high temperature, which can block a coal body from contacting with oxygen. In addition, the composite inhibitor can capture hydroxyl free radicals generated during the chain-cycle reaction and destroy peroxide free radicals, and can also interact with an active moiety in coal to form a stable structure such as ether linkage and hydrogen bonding, thereby achieving permanent inhibition of low-rank coal.

Abstract: A method for efficiently treating spontaneous ignition of the remaining coal in a large area goaf of a shallow-buried coal bed, which method integrates leaking stoppage, airflow control and fast inerting and cooling so as to efficiently prevent and treat the spontaneous ignition of the remaining coal in the large area goaf of the shallow-buried coal bed.

Abstract: A method for efficiently treating spontaneous ignition of the remaining coal in a large area goaf of a shallow-buried coal bed, which method integrates leaking stoppage, airflow control and fast inerting and cooling so as to efficiently prevent and treat the spontaneous ignition of the remaining coal in the large area goaf of the shallow-buried coal bed.

Abstract: A preserved-amplitude RTM-based FWI method is used to obtain an image of an explored subsurface formation. Model data corresponding to detected data is generated using a velocity model of the formation. Residuals representing differences between the modeled data and the detected data are back-propagated to then update the velocity model a local optimization based on a deconvolution formula employing a backward propagating wavefield and a forward propagating wavefield. Geophysical features of the formation are imaged based on the updated velocity model.