A raw coal transparent pouring part, preparation method and permeability test device

Abstract

The invention discloses a raw coal transparent pouring part, a preparation method and a permeability testing device. The permeability testing device includes a test piece, an axial pressurization system, a hydraulic loading system, a high-speed camera, and a data acquisition system; the shaft Axial pressure is applied to the test piece by the pressurization system, hydraulic pressure is applied from the top of the test piece by the hydraulic loading system, and the drainage pipeline discharges the permeated water from the lower part of the test piece into the flat-bottomed flask on the electronic balance. The data is sent to the controller, and the high-speed camera shoots the seepage process of the aqueous solution with milky white dye in the coal fissures in real time, so as to realize the visual observation of the seepage path of the raw coal fissures. The invention can realize the visual observation of the seepage path of the raw coal fissures, and obtain the permeability coefficient of the raw coal under different stress states.

Description

technical field [0001] The invention relates to a coal body permeability test device and method, in particular to a raw coal transparent casting, a preparation method and a permeability test device. Background technique [0002] Water inrush accidents in coal mines are one of the most serious disasters in coal mines. The outbreak of water inrush accidents in coal mines is closely related to the seepage characteristics of coal bodies. The permeability characteristics of coal and the seepage path of coal fractures have very important theoretical significance and engineering application value. [0003] At present, most of the specimens used in coal permeability testing are regular briquettes and raw coal samples. The production of briquettes is relatively easy. Add a little water to the polished coal powder and mix well, weigh a certain amount with a balance according to experience, put it into the prepared mold, apply a certain pressure, and take out the coal sample after st...

AI Technical Summary

Problems solved by technology

Coal briquettes are easy to process, but there is a big difference in the number of fracture structure, degree of deformation and peak strength of raw coal. There are considerable differences between the coefficients

[0004] For the preparation of raw coal samples, many difficult problems are often encountered: in the process of drilling the test block, it is easy to move due to the force of the drill bit, so that the obtained samples cannot meet the standard; for coal rocks with low strength and easy to break Blocks, because the coal and rock blocks are only subjected to point holding force and drill bit pressure, the external force is unbalanced, coupled with the action of water, they are easily damaged and broken during the rock drilling process, and the required test pieces cannot be obtained.

[0005] At present, in the penetration test of regular raw coal samples, most of the raw coal samples used are The regular cylinder of the coal piece is small in size, and the coal body cracks contained in the coal sample are not many, which cannot fully reflect the crack structure of the coal body in the coal mining face

Moreover, the test of the permeability coefficient of coal samples is carried out in a triaxial chamber. When coal samples are placed in a triaxial pressure chamber, the seepage path of water in the coal fractures cannot be observed, and the visual observation of the seepage in coal fractures cannot be realized.

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