RU2304218C1 - Method for coal excavation from thick steep bed - Google Patents

Abstract

FIELD: mining, particularly underground development of thick steep beds with blasthole drilling.

SUBSTANCE: method involves preparing excavation field by cutting mining levels, wherein haulage and ventilation drifts, which define level height are cut; cutting sublevel drifts to divide each level into sub-levels; dividing sublevels along strike into blocks by coal chute and vent chute forming; mounting coal discharge feeders and coal transportation conveyer on ground of each sub-level drift; cutting compensatory drifts over each sub-layer drift; cutting blocks by drilling around operation from compensatory drift and blasting coal in block so that pillar is left; distributing coal from block to conveyer. Sub-level drifts are made as trenches covered with panels. Trench sides are provided with depressions for feeder receiving.

EFFECT: provision of coal excavation and transportation from caved block, increased efficiency of coal excavation from thick steep beds due to increased mine safety, possibility to retain mine lining during blasting and discharge operations, possibility of safe conveyer, feeder and other equipment disassembling for next block excavation.

4 cl, 4 dwg

Description

The technical solution relates to mining, namely to underground mining of powerful steep coal seams with drilling and blasting, and can be used to remove and transport coal from a collapsed block.

Well-known methods of mining powerful steep coal seams (see S. D. Sonin and others. Underground mining of deposits. State scientific and technical publishing house of literature on mining - M., 1961. - P. 421-423, Fig. 225), including the preparation of the excavation field by cutting floors, carried out by the excavation of the haul-off, parallel and sub-floor drifts with the division of the sub-floors into blocks by means of coal-run and ventilation furnaces, passed through the dip of the formation. The coal destroyed by the explosion from the block is discharged to the haul-off drift through coal-run furnaces 5–6 m long, passed between the parallel and haul-off drifts at a distance of 6–7 m from each other along the strike.

The main disadvantages of this method are:

large (40 ÷ 50%) coal losses;

high fire hazard;

increasing the ash content of coal mined;

cogging of coal-blast furnaces in coal production.

The reason for these shortcomings is the incomplete and uncontrolled release of coal, in which large lumps of coal clog (clog) sections of coal-blast furnaces, especially in their upper part, and coal production ceases. Since the distance between these furnaces is 6-7 m, the coal located between them is also not released, and an uneven release of coal is obtained, in which the crushed rock penetrates between the coal flows and enters the coal-blast furnaces, creating an increased ash content of the produced coal. As a result of the unreleased coal destroyed by the explosion being left in the block, there is a great danger of an endogenous fire.

A known method of coal extraction, implemented using a complex for unloading coal from a collapsed block according to the certificate of the Russian Federation for utility model No. 12180, E21C 41/18, publ. in BI No. 12, 1999.

In this method, the preparation of the excavation field and blocks is performed in the same way as in the analogue described above. The difference from the analogue here is that coal is unloaded from the collapsed block through coal-discharge furnaces equipped with bunkers with carbon-discharge and discharge windows, equipped with gates in the form of segments of massive chains. The carbon drain windows are reinforced with steel sheets to which pneumatic vibration exciters are rigidly attached.

The movement of coal along the carbon windows of the bins reinforced with steel sheets is carried out under the influence of its own weight under the vibration effects of pneumatic vibration exciters, which provides a more efficient discharge of coal passing through coal-fired furnaces with bins to the discharge windows compared to the specified analogue. But the main problem has not been resolved: the upper part of the hopper, which is in contact with coal blown up on a parallel drift and receives the released coal, is clogged to the height of the coal blast furnace, and the coal blown up in the block remains unreleased, which reduces the efficiency of the method.

There are two reasons for this:

- coal becomes clogged upon entry and movement in bunkers up to 6–7 m high, equal to the size of the coal pillar between the recoil and parallel drifts;

- there is no continuous controlled release of blasted coal, because the release is carried out not over the entire area of the bottom of the block, but into the bunker with coal-discharge windows having a limited cross section and the distance between which is usually 6 meters or more. Block coal remaining unreleased creates an increased fire hazard. In addition, driving coal-blast furnaces with bunkers increases the amount of preparatory work.

The closest in technical essence and the set of essential features is a method of coal extraction from powerful steep seams according to the patent of the Russian Federation No. 2261329, class. E21C 41/18, publ. in BI No. 27, 2005.

In this method, the preparation of the excavation field is carried out in the same way as in the described analogue. The difference from the analogue is that all the destroyed coal lies on the section feeders, directly through which coal is released onto the conveyor. Exploded coal lying directly on the sectional feeders is transported to the conveyor by means of the inclusion of sectional feeder drives. The release of coal from the block to the conveyor can be carried out over the entire area of the bottom of the block due to the installation of sectional feeders one after the other along the entire length of the sub-floor drift within the boundaries of the block, which ensures continuous uniform release of all blasted coal over the entire area of the bottom of the block.

The disadvantage of this method is the high probability of the destruction of the drift mount and the sub-floor drift itself when blasting whole pillars of coal directly above the sub-floor drift. In addition, if the shtrekoy mount is broken, it is impossible to dismantle the conveyor and other equipment.

The technical task of the proposed solution is to increase the efficiency of coal extraction from powerful steep seams due to the following factors:

- safety of work in the face;

- safety mounting workings during blasting and release;

- the possibility of safe dismantling of the conveyor, feeders and other equipment for working off the next unit.

The problem is solved in that in the method of coal extraction from powerful steep seams, including the preparation of a mining field by cutting floors, for which there are retractable and ventilation drifts that limit the height of the floor, underfloor drifts pass, dividing the floors into subfloors, they are divided into blocks into blocks by driving coal-blasting and ventilation furnaces, at the same time, feeders for the release of coal and a conveyor for transporting coal are mounted on the bottom of the floor drift on the bottom of each block, and above the floor deck ekami tested compensating drifts, block refinement, which is performed by oburivaniya of compensating drift and blasting of coal in block leaving pillar, subsequent oburivaniya pillar sublevel of drift and blasting in coal entirely and exercise release of the coal onto the conveyor unit. According to the technical solution, sub-floor drifts are performed in the form of ditches, which are covered with shields. Niches pass on the sides of the ditches, and feeders place them in these niches.

When performing sub-floor drifts in the form of ditches covered with shields, the entire load from the explosion or collapsed rocks is transferred to powerful shields, so the ditches located under them practically do not require fastening. This preparation of the unit in combination with the niches in the sides of the ditches and the feeders installed in them fully ensures the safety of work in the face, the safety of the workings under the boards and the guaranteed possibility of safe dismantling of the conveyor, feeders and other equipment for working out the next block. All these factors provide an increase in labor productivity and, as a result, an increase in the efficiency of coal extraction.

It is advisable in the sides of the ditches every 2 ÷ 3 m along their entire length to pass niches, and the height of the niches should be chosen equal to the height of the ditch.

To maintain the required area of shield support along the edges of the ditch, niches pass through 2–3 m, depending on the strength of coal. The height of the niche should be equal to the height of the ditch, since the feeder placed in it at an angle to the horizontal should transport coal from the top of the ditch (or from the edge of the shield located above the ditch) to the scraper conveyor mounted on the bottom of the ditch.

It is also advisable to niche in the opposite sides of the ditch pass in a checkerboard pattern. This ensures, firstly, the reliability of the shield support on the sides of the ditch, and secondly, a uniform areal discharge of coal from the block with minimal losses, since the distance between the niches in this case is minimal.

It is also advisable to additionally lean the shields on the supports with racks installed along the sides of the ditches in the area of niches. The proposed additional shield supports over the niches ensure the safety of the interface between the niches and the sides of the ditches, the safety of the niches and, therefore, the feeders located in them, as well as the reliable continuous support of the boards along their entire length.

The essence of the proposed method is illustrated by an example of its implementation and the drawings of figures 1 ÷ 4, where:

figure 1 shows the technological scheme of the proposed method (projection on a vertical plane along the strike of a coal seam);

figure 2 shows a view of I in figure 1 on board the ditch;

figure 3 - cross section aa in figure 1 (cross-sectional view of the extension of the formation);

figure 4 - section BB in figure 3 (plan view of the conveyor and niches with feeders, a shield with pickups is not conventionally shown).

The method of coal extraction from powerful steep coal seams is implemented as follows.

Preparation of the excavation field is carried out by cutting floors 1 (Fig. 1), for which there are retractable 2 and ventilation 3 drifts that limit the height of floor 1. Floors 1 are divided into floors 2 by driving underfloor drifts in the form of ditches 5.

Then, they are divided along the strike of the sub-floors 4 into blocks 6 by means of sinking of coal-run 7 and ventilation 8 furnaces. Over the ditches 5 are compensation drifts 9 (Fig.1, 3). On top of the ditch 5 is covered with shields 10 (Fig.2, 3), resting them on the sides of the ditches 5 and grabs 11 with racks 12 (Fig.2, 3).

On the bottom of each block 6, which is the bottom 13 (Fig.2, 3) of the ditch 5, pass in the sides of the ditches 5 (Fig.2, 3) in a checkerboard pattern niches 14 (Fig.2, 3) with a depth and width equal to the size of the feeder 15, and a height equal to the height of the ditch 5. The distance along the sides of the ditch 5 between the niches 14 is 2–3 m, depending on the strength of the coal. In niches 14, feeders 15 are mounted for the release of coal on a conveyor 16 (Fig. 4), which is mounted in the middle of a ditch 5 on its bottom 13. A conveyor 16 transports coal along the entire length of block 6 to a coal-burning furnace 7.

The mining of blocks 6 is carried out in descending order, starting from the upper sub-floor 4. In the compensation drift 9 of the first mining block 6, an array of coal is drilled, the bore holes are charged and coal is destroyed by an explosion. The blasting is carried out in such a way that an undisturbed pillar of coal with a height of 2 ÷ 3 m remains over the ditch 5. This is necessary so as not to disturb the shield 10, the fastening of the ditch 5 and niches 14 with feeders with a massive explosion.

Then, from a niche 14 and a ditch 5, this coal pillar is drilled, charged and blown, after which all the destroyed coal of block 6 rests on feeders 15 and shields 10. Directly through feeders 15 coal is conveyed to conveyor 16, through which coal is transported to a coal-blast furnace 7, from where it is loaded into transport at the haulage drift 2.

Coal production and transportation are controlled remotely from a control panel (not shown in FIG.) Located in a safe place. By remote switching on of certain groups or individual feeders 15, the blasted coal is controlled to be released, loaded and transported to a coal-blast furnace 7. Remote control ensures the safety of work in block 6. At the same time, they can carry out coal production in two or more blocks 6 of the sub-floor 4. After mining of all blocks 6 of the sub-floor 4, the feeders 15 and the conveyor 16 are reassembled into sub-floor drifts of the underlying sub-floor, the spent upper sub-floor 4 is isolated and its fire prevention is carried out.

Claims (4)

1. A method of extracting coal from powerful steep seams, including preparing a excavation field by cutting floors, for which there are haul-off and ventilation drifts that limit the height of the floor, underfloor drifts pass, dividing the floors into subfloors, they are divided along the stretch of the subfloors into blocks through the passage of coal-releasing and ventilation furnaces, while on the soil of a sub-floor drift, feeders are mounted on the bottom of each block for the release of coal and a conveyor for its transportation, and compensation drifts are passed over the sub-floor drifts , the mining of blocks is carried out by drilling from a compensating drift and blasting coal in the block, leaving the pillar, then drilling the pillar from the floor drift and blasting coal in its entirety, and releasing coal from the block onto the conveyor, characterized in that the floor drifts are made in the form of ditches, which cover with shields, while in the sides of the ditches pass niches, and feeders are placed in these niches. 2. The method according to claim 1, characterized in that the niches in the sides of the ditches pass every 2 ÷ 3 m along their entire length, and the height of the niches is chosen equal to the height of the ditch. 3. The method according to any one of claims 1 and 2, characterized in that the niches in the opposite sides of the ditch are staggered. 4. The method according to claim 1, characterized in that the shields are additionally supported by pickups with uprights installed along the sides of the ditches in the area of niches.

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