RU2287688C1 - Method for extracting thick flat-lying coal beds - Google Patents

Abstract

FIELD: mining industry, possible use during underground extraction of thick flat-lying coal beds.

SUBSTANCE: method includes dividing coal bed on two layers, processed by faces, equipped with mechanized supports, advance processing of upper layer, processing of lower layer while leaving a coal cluster between layers. Depth of zone of destroyed coal, forming in coal massif, positioned below upper layer, under effect from supporting pressure, occurring in front of upper layer face, is determined. Between upper and lower layers a coal cluster is left with thickness not less than a total of aforementioned depth of destroyed coal zone and minimally allowed thickness of coal cluster not destroyed by supporting pressure, left between upper and lower coal layers, during descent of which its cave-in occurs in bottom space of face.

EFFECT: prevented spontaneous cave-ins of ceiling rock in bottom space of lower layer faces.

2 dwg

Description

The invention relates to mining and can be used in underground mining of powerful flat coal seams.

There is a method of developing powerful coal seams using a layered development system (Copyright certificate No. 93008888 IPC E 21 C 41/00). When using this method, a coal seam is divided into two layers, worked out by mechanized supports in a descending order. When excavating the upper layer, the collapsed roofing rocks are treated with gel-forming compounds to the thickness of the artificial roof created. The bottom layer is excavated under the protection of an artificial roof. The disadvantages of this method are the reduction of the daily load on the working faces of the upper layer due to the time spent on operations to feed the compositions into the worked out space and significant costs for its implementation.

A known method of developing powerful shallow seams of coal, adopted as a prototype method (Gromov Yu.V., Bychkov Yu.N. Management of rock pressure in the development of powerful shallow seams of coal. - M .: Nedra, 1985, p.57-59) , including the separation of the coal seam into two layers, worked out by mechanized supports. Advance mining of the upper one is carried out, and the mining of the lower layer is carried out with a coal bundle left between the layers.

The disadvantage of this method is the increased intensity of the collapse of the roof rocks in the lava of the lower layer, associated with the destruction of the interlayer bundle before moving the sections of the powered roof support to the face after coal mining.

The technical result of the proposed method is to eliminate the disadvantages of the known method, namely the prevention of roof collapse in the lava of the lower layer.

The technical result is achieved by the fact that in the method of developing powerful flat seams of minerals, comprising dividing the coal seam into two layers, worked out by lavas equipped with mechanized supports, advancing the mining of the upper layer, mining the underlying layer with the remaining coal layers between the layers, according to the invention, determine the depth of the zone destroyed coal forming in a coal mass located below the upper layer under the influence of reference pressure arising in front of the face you topsheet and coal power pack to leave between the upper and lower layers of the coal is determined from the inequalities:

h≥l + a,

h is the total power of the coal pack left between the upper and lower layers of coal;

l is the depth of the zone of destroyed coal formed in the coal mass located below the upper layer under the influence of reference pressure arising in front of the face of the lava of the upper layer;

and - the minimum allowable power of the coal pack not destroyed by the reference pressure left between the upper and lower layers of coal, which decreases when it collapses in the bottomhole space of the lava.

The essence of the proposed method is illustrated by the drawings presented in figure 1 and figure 2. Figure 1 presents a schematic diagram illustrating the mining of the upper layer, and figure 2 presents a schematic diagram illustrating the mining of the lower layer.

In the figures: 1 - a practiced reservoir with a capacity of m _p ; 2 - the upper layer with a capacity of m _in ; 3 - the lower layer with a capacity of m _n ; 4 - direct roofing power b; 5 - direct soil with a capacity of s; 6 - coal pack with full power h left between the upper and lower layers of coal; 7 - a zone of destroyed coal of depth l, arising in a coal mass located below the upper layer, when mining lava 8 of the upper layer; 9 - coal pack, not destroyed by the reference pressure of the minimum allowable power a, left between the upper and lower layers of coal. With a decrease in the minimum allowable power a of coal pack 9, the collapse of coal pack 6 occurs in the bottomhole space of the lower lava 8; 10 - mechanized support of the face; 11 - worked out space; L is the depth of propagation into the massif in front of the face of the upper lava of the zone of destroyed coal formed in the coal mass located below the upper layer.

The method is as follows. Powerful coal seam 1 is divided into two layers, the upper - 2 and lower - 3, which are mined by a shearer using mechanized lining 10. Advance mining of the upper layer 2 is carried out, and the mining of the lower layer 3 is carried out with the remaining between the upper 2 and lower 3 layers of coal packs 6. The total power h of the coal pack 6 is determined as the sum of the depth l of zone 7 of the destroyed coal and the power of the minimum permissible undamaged zone 8. The depth l of zone 7 is determined when mining the upper layer 2. The coal pack 6 prevents pore collapse One roof 4 in the lavas 8 of the lower layers 3 and collapses in the worked-out space 11 after moving the sections of the powered roof support 10.

The parameters of the proposed method is determined by using well-known methods of mine, laboratory or analytical studies, taking into account specific mining and geological and mining conditions.

Using the proposed method allows to exclude spontaneous caving of roof rocks in the worked out space of lavas of the lower layers, therefore, to increase the safety of mining and increase the average daily load on lava.

Achieving a positive effect is due to the fact that with the received power of the coal pack left between the upper and lower layers (h≥l + a), its destruction between the face of the lava and the overlap of the lining sections is excluded.

The expected economic effect when using the proposed method for mining powerful flat coal seams in the mines of the Kuznetsk basin will be more than 3-6 million rubles per year per lava.

The field of rational use of the proposed method are shallow seams of coal with a capacity of 6-12 m

Claims (1)

A method for developing powerful shallow seams of minerals, comprising dividing a coal seam into two layers, worked out by lavas equipped with mechanized supports, advancing the mining of the upper layer, mining the lower layer, leaving a coal pack between the layers, characterized in that they determine the depth of the area of the destroyed coal formed in coal mass located below the upper layer, under the influence of reference pressure arising in front of the face of the lava of the upper layer, and the power of the coal pack left m between the upper and lower layers of coal, is determined from the inequality: h≥l + a, h is the total power of the coal pack left between the upper and lower layers of coal; l is the depth of the zone of destroyed coal formed in the coal mass located below the upper layer under the influence of reference pressure arising in front of the face of the lava of the upper layer; and - the minimum allowable power of the coal pack not destroyed by the reference pressure left between the upper and lower layers of coal, which decreases when it collapses in the bottomhole space of the lava.

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