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After coal is treated by thermal solution of solvent, a certain amount of thermal solution oil and residue can be obtained, and the macromolecular network structure in coal can also be relaxed. These will inevitably affect the emission of harmful gases and distribution of the pore structure when the residue is made into activated carbon (AC). In this paper, the effects of thermal solution pretreatment on the microcrystalline structure, surface properties, pore structure of resultant ACs at different temperatures, and their catalytic performances in methane decomposition to hydrogen were investigated. The results show that the surface oxygencontaining functional groups of the residue-based ACs are changed, and the specific area of ACs increases from 1730 to 2652 m 2 /g with the increase in activated temperature. The pore diameter distribution of ACs also is changed. In the process of methane decomposition to hydrogen, the residue-based ACs show higher catalytic activity than coal-based ACs. AC-1123-1 and AC-1123 show the best stability, while AC-823-1 has the highest initial activity. With the increase in activated temperature, residue-based ACs show higher activity and stability, and partial fibrous carbon is deposited on the surface of ACs after the reaction. It is thought that increased mesoporosity is beneficial to the catalytic activity and stability of AC in methane decomposition to hydrogen, and the reduction of surface oxygen-containing functional groups contribute to the formation of fibrous carbon on the surface of AC after the reaction.

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Drilling and blasting technology is one of the main methods for pressure relief in deep mining. The traditional method for blasting hole blockage with clay stemming has many problems, which include a large volume of transportation, excess loading time, and high labor intensity. An environmentally friendly blast hole plug was designed and developed. This method is cheap, closely blocks the hole, is quickly loaded, and is convenient for transportation. The impact test on the plug was carried out using an improved split Hopkinson pressure bar test system, and the industrial test was carried out in underground tunnel of coal mine. The tests results showed that, compared with clay stemming, the new method proposed in this paper could prolong the action time of the detonation gas, prevent premature detonation gas emissions, reduce the unit consumption of explosives, improve the utilization ratio, reduce the labor intensity of workers, and improve the effect of rock blasting with low cost of rock breaking.

A new type of cigarette butts/coal-based composite porous carbon was prepared by potassium hydroxide chemical activation method and used for methane decomposition to hydrogen. The effects of mass mixing ratio of the used cigarette butts/coal and carbonization temperature on the surface properties and structure of carbon materials were studied. The results show that the optimal mass mixing ratio of cigarette butts/coal is 1:3, and the increase in temperature can promote the specific surface area of carbon materials from 1850 to 2785 m 2 /g, the distribution of pore size is also changed from a large number of micropores to mesopores, and the structure became more disordered. DT/YT-3-1023 has the highest initial activity, DT/YT-3-1123 has the highest stability, and a certain amount of carbon fibers are deposited on the surface of carbon materials after the reaction.