RU2263213C1 - Method for thick steeply inclined fire-hazardous bed mining with caving - Google Patents

Abstract

FIELD: methods of underground mining, particularly for mining thick steeply inclined coal beds liable to spontaneous ignition.

SUBSTANCE: method involves dividing bed into two inclined layers by establishing interlayer protective coal pillar; cutting the inclined layers in blocks along with forming air-tight bridges between the blocks; performing sublevel benching of upper layer having thickness of 1.5-1.8 m along strike with leading on upper sublevel; excavating lower sublevel by columns along bed fall with the use of movable shield supports. Lower layer may be divided into two or more shield columns.

EFFECT: increased safety of bed mining.

2 cl, 3 dwg

Description

The invention relates to mining, and specifically to a technology for developing powerful coal seams of steeply inclined bedding, prone to spontaneous combustion.

There are various methods for developing powerful coal seams with inclined layers, both with roof collapse and with laying of worked out space, both with erecting an interlayer overlap and with leaving an interlayer coal bundle (see, for example, Mining - Encyclopedic Handbook, M., Ugletekhizdat , 1958, p. 238-245).

One of the serious drawbacks of the inclined bed development system is its high fire hazard, which is usually a consequence of large coal losses in interlayer packs and low speeds when mining excavation sites. Therefore, when choosing a method for developing a powerful steep-slope formation, it is necessary to strive for a minimum number of inclined layers and a higher productivity of their downhole equipment.

There is a method of layer-by-layer development of powerful gentle layers of minerals, including the excavation of the upper and lower layers of minerals by lavas, leaving a rocky layer in the worked out space and cutting compensation gaps (see AS USSR No. 1239332 according to class IPC E 21 C 41/04 , 1986).

The closest technical solution to the proposed technology is the development of a powerful inclined formation with two inclined layers and the use of lining or KTU complexes (see "Mining" Terminological Dictionary, M., Nedra, 1990, p. 550-551).

The disadvantages of the prototype include the following disadvantages: low load on the excavation section, the large complexity of erecting a flexible metal floor in the upper mounting layer, large losses of coal in the interlayer thickness, which increases the degree of spontaneous combustion of coal in the excavation section.

The purpose of the invention is the development of powerful steeply inclined coal fire hazardous seams without spontaneous combustion of the coal seam in the excavation area.

This goal is achieved by the fact that a powerful steeply inclined coal seam, prone to spontaneous combustion, is worked out by two inclined layers, and the upper layer with a thickness of 1.5-1.8 m is worked out in columns along the strike with division into sub-floors within the excavation block, and the lower layer by width the block is worked out by strips (pillars) in the fall using mobile shield supports of the SK type, either to the width of the block with one shield face or two shield faces, depending on the geological conditions of the reservoir section and on the structure and mobile shield support.

The description of the invention is illustrated by drawings, where figure 1 shows a profile projection of a fragment of the technological scheme with the image of the upper and lower inclined layers; figure 2 and figure 3 shows the mining scheme, respectively, of the upper and lower layers.

A steeply inclined coal seam with a thickness of 9-11 m, prone to spontaneous combustion, is prepared by the main drift 1, passed from the cross-turn (not shown in the drawing), and ventilation 2 and 3. The excavation section of the seam is divided into blocks 4 by a length determined by the degree of spontaneous combustion of coal and technological parameters adopted development system. At the boundaries of each excavation block 4 are inclined workings 5 located in the upper layer of the reservoir. Each excavation block 4 is worked out by two inclined layers: the upper 6 and the lower 7. The upper layer 6 with a thickness of 1.5-1.8 m is worked out by sub-floors along strike - with lavas with a wooden timber support. The lower layer 7 is worked out by two or more pillars in the fall using the shield type SK.

In preparing the excavation section of the reservoir in the upper layer at the level of the return horizon, a parallel drift 8 is carried out, which is connected by inclined orts 9 with the main drift 1. The upper layer 6 is divided into 2-3 sub-floors (lavas) with an inclined length of 25-35 m.

Preparation and development of the excavation section is carried out blockwise from its far boundary starting from the upper layer 6. Between the upper layer 6 and the lower layer 7, a protective pillar 10 of 2.5-3.0 m thickness is left, which prevents the penetration of collapsed rocks into the bottomhole space of the shield lining type "SK". When coal is mined in the upper layer 6, sub-floor pillars between lavas, and when coal is mined in the lower layer 7, inter-panel pillars are treated with anti-pyrogenic compounds. Anti-pyrogenic substances are also introduced into the protective coal pillar 10. As the next face is mined, airtight bridges are erected in the workings located along the strike of the formation. In this case, the column width by drop in the lower layer 7 is equal to the length of the sub-floors along the strike of the upper layer 6.

The parameters of the extraction blocks are taken depending on the speed of their mining and the time of the incubation period of spontaneous combustion of the coal seam, which is one of the decisive factors for the trouble-free mining of the mining blocks.

The coal pillar 10 left between inclined layers 6 and 7 to protect against penetration of collapsed rocks under the shield support is also a positive factor for the successful development of the coal seam. However, the collapsed rocks of the upper layer 6, located above the coal protective layer 10, create favorable conditions for the uniform distribution of rock pressure on the shield support.

And, finally, the combination of the proposed technological methods allows increasing the load on the mining section, increasing the speed of mining the mining blocks and avoiding the occurrence of endogenous fires during the development of powerful coal seams - this scourge of underground technology for the development of coal deposits with fire hazardous seams.

Claims (2)

1. A method of developing a powerful steeply inclined coal fire hazardous seam with a collapse of the roof, comprising dividing the seam into inclined layers, characterized in that the seam is divided into two inclined layers, dividing them by an interlayer protective coal whole, with the upper layer having a thickness of 1.5-1, 8 m is worked out by sub-floors along the strike of the formation ahead of the upper lower floors, and the lower layer is worked by columns in the fall using mobile shield supports of the SK type, while the development of inclined layers is carried out in blocks with erection between blocks of airtight jumpers. 2. The development method according to claim 1, characterized in that the lower layer worked off by the columns in the fall is divided into two or more panel posts.

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