RU1770585C - Method for opening steep outburst-hazard seam - Google Patents

Abstract

Usage: the invention relates to the mining industry and provides increased safety when opening a steep outburst formation. SUMMARY OF THE INVENTION: preparatory excavation at the intersection with an outburst formation is carried out under the protection of a concrete plug formed when a rock plug is drilled by a combine harvester over the entire production cross section. 2 ill.

Description

The invention relates to the mining industry and can be used for opening steep outburst formations.

A known method of opening a steep outburst formation under the protection of a metal frame (1).

A disadvantage of the known method lies in the great complexity of drilling and securing pipes.

The closest in technical essence and the achieved effect is a method of opening a steep outburst seam during contour moistening of a coal mass, including drilling wells through a rock plug to a coal seam, introducing pipes into them, sealing pipes, and hydraulic washing through central and peripheral wells (2).

A disadvantage of the known method is the low efficiency and safety of opening operations.

The purpose of the invention is to improve work safety.

The claimed method is illustrated in Figs. 1 and 2 and is carried out as follows.

When approaching the outburst coal seam 1 of the open-cut mine 2 at a distance of 3–4 m from the seam, a central borehole 3 and 4 peripheral 4 through rock plug 5 to the seam 1. Peripheral wells 4 are drilled per production line by 2 m. t pipes 6, inject water into the formation, hydrate the coal seam 1, forming a cavity 7, at the point of intersection of it with an open hole 2 along the entire cross-section 8 through central 3 and peripheral 4 and between peripheral 4 wells lead sequentially between two of them, then in wells In the indicated sequence of hydraulic washing, the concrete is pumped into concrete and a protective plug 9 is formed from it.

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The opening of the formation is carried out under the protection of the plug 9, the width of which, under favorable conditions for conducting hydraulic washing of the formation and injection of concrete, can be equal to 4 m (Fig. 2). By favorable conditions, the authors mean a homogeneous coal seam without inclusions and geological disturbances, when the hydraulic wash-out around each of the wells is carried out uniformly in all directions. In the presence of inclusions and geological disturbances, the minimum distance of the cavity 7 from the cross-section of the opening 2 is 2 m because peripheral wells 4 were drilled exactly at such a distance from the border of the openings 2. The width of the protective concrete shell, equal to 2 m, was chosen for double protection of the shell continuity. The fact is that when it is drilled by a tunneling machine, microcracks can sometimes appear in the casing up to 1 m long. With a concrete casing width of 2 m, a double margin of casing strength is provided. As regards the strength of the casing against the possible manifestation of coal and gas emissions, even when used in the construction of Portland cement grade 300, the preparatory mine is protected from significant sudden emissions of coal and gas. For example, 1 cm2 of the surface of the protective shell is able to withstand an axial load equal to 0.75 "hedgehog or 0.75 300 kg / cm2 221 kg / cm12, then 1 m of the cross-section of the protective shell is able to withstand the initial impulse from the sudden release of coal and gas, equal to 225 kg / cm2 10000 cm2 or 2250 t and, accordingly, 2 m2 - 4500 t, etc. In mining practice, such sudden emissions of coal and gas are rare - their main amount is from tens to several hundred tons of coal emitted.

Thus, the proposed method for opening a steep outburst layer ensures the safety of mining operations in the preparatory mine.

An example of a method for opening a steep outburst formation.

Under mine conditions, the steep discharge zone of the Diamond Suite with a thickness of 0.75 m, a dip angle of 60 °, was opened with a cross-section with a cross section of 11.6 m2. When approaching the formation from a distance of 3 m, 13 wells of 070 mm were drilled to the formation — one control and twelve peripheral ones. Peripheral wells were drilled beyond the 2.0 m production circuit. 050 mm pipes were introduced into the wells, sealed, and water was washed sequentially through the central and each peripheral well, as well as between two adjacent peripheral wells. After hydraulic washing in the indicated sequence, 30 m3 of concrete solution was pumped into the wells. When a solution appeared in the well, the latter was sealed. After the concrete mortar hardened, after 5 days, rock and concrete plugs were drilled to the cross section of the opening excavation using a combine. The width of the protective concrete sheath was 2.0 m. There were no discharges at the intersection of the formation with an opening excavation.

The proposed method allows to increase the safety of work when opening steep outburst hazardous formations.

Claims (1)

The claims A method for opening a steep outburst hazardous formation, including drilling central and peripheral wells through a rock plug to a coal seam, introducing pipes into them and sealing them, hydraulically washing the coal seam through a rock plug at the intersection of the production holes, drilling the rock plug with a combine and crossing the formation with production, different the fact that, in order to increase the safety of work, hydraulic washing between the central and peripheral wells and between peripheral wells are carried out sequentially between mind of them, then the well in this order gidrovymyvani pumped concrete mix and form from it the protective tube, the reservoir and the intersection generation are under its protection. Ln - 8