RU2344292C1 - Method of development of thick flat-lying coal bed on clots of irregular shape - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: method of development of thick flat-lying coal bed on clots of irregular shape is intended for extraction of coal from sections with limited resources which for economic reasons can not be extracted by means of complex mechanisation. The method includes preparing an extraction pillar by making transport and ventilation entries at a bed roof and a hydro-transport entry at a bed floor with the axis of the hydro-transport entry set-off against the axis of the transport entry to the direction of massif. The extraction pillar is divided into strips with stopes; simultaneously there is assembled a roof bolting while leaving between-stopes massifs virgin. The stopes are made at the bed roof from the transport to ventilation entry. Neighbour stopes are linked with connections. A borehole is drilled approximately along the axis of the stope from the hydro-transport entry to each stope. A hydro-transport slit is cut with a hydro-monitored jet from the head of the borehole to the ventilation entry along the axis of the stope till the bed floor, and in the reverse direction coal is extracted with a hydro-monitor below the stope floor and partially under the massif from the flank side. Transporting of loose coal in mine workings above the stope floor is performed with traditional means, for example with self-propelled car and conveyer, while below the stope floor it is transported in form of pulp. After extraction of coal in stopes there is performed extraction of massif under the transport entry and further - under the ventilation entry by the similar method.

EFFECT: increased efficiency and safety of development.

2 cl, 6 dwg

Description

The invention relates to mining, in particular to methods for developing coal seams using hydromechanization tools.

A known method for the development of shallow coal seams by means of hydromechanization, including dividing the floor into floors by ventilation and accumulating drifts, and the sub-floor into excavation blocks by block furnaces. In turn, the extraction blocks are prepared by excavation furnaces and faults, and coal extraction is carried out by hydraulic monitors or mechano-hydraulic combines in openings [1]. The disadvantage of this method is that its use requires extended excavation fields both along strike and dip, and the number of such excavation fields is very limited.

As a prototype, a method has been adopted for developing powerful shallow coal seams with diagonal pillars with combined approaches, including the preparation of a excavation column by conducting transport and ventilation drifts, the contouring of a mining block of a running, slurry and transport furnaces, dividing a mining block into diagonal strips by excavating chambers near the formation soil, drilling wells between adjacent mining chambers, hydraulic breaking of coal in a mining chamber and transport of chipped coal [2].

The disadvantages of the prototype are:

- the need for extended excavation fields;

- increased operational loss of minerals;

- increased volume of preparatory workings;

- an increased accident rate for cleaning operations, since coal is mined in the chamber without fixing the roof, and the rocks of the roof are eroded by water from the barrel of the monitor, as a result of which the collapse of the roof rocks in the chamber often occurs before the bulk of the coal reserves of the chamber are recovered.

These shortcomings reduce the efficiency of developing powerful flat coal seams, especially coal reserves, concentrated in areas of limited length and irregular shape.

The aim of the invention is to increase the efficiency of the development of powerful flat coal seams occurring in difficult geological conditions, by profiling the mining column along the boundaries of the site and reducing accident rate by organizing hydraulic production below the soil level of the mining chamber.

This goal is achieved by the fact that in the method of developing a powerful flat coal seam, including the preparation of a mining column by carrying out transport and ventilation drifts, dividing the mining column into stripes by mining chambers, leaving the pillars, drilling wells, coal breaking in the mining chamber, transporting the beaten-out coal by mine and control of mountain pressure by keeping the roof on pillars, a ventilation drift is carried out along the upper boundary of the area near the formation roof, a transport drift is also carried out at the roof flotation, but along the lower boundary of the site in straightforward manner, under the transport drift near the formation soil, a hydrotransport drift is carried out with its axis offset relative to the axis of the transport drift towards the prepared array, excavation chambers are carried out from the transport to the ventilation drift at the formation roof with the construction of an anchor lining, adjacent the extraction chambers are knocked down by failures, the well is drilled from the hydrotransport drift into the space of the extraction chamber in a plane passing along its axis, and provide separation of the trans tailor flows at the initial stage of the extraction of the chamber below its soil, from the wellhead to the ventilation drift along the axis of the extraction chamber, a hydrotransport slot is cut through the hydraulic jet to the formation soil, and in the opposite direction, coal is taken out below the excavation chamber soil and partially below the entire flank side, after coal extraction in the chambers carry out the extraction of the pillar under the transport drift, and then under the ventilation in a similar way.

The method is illustrated by drawings, so figure 1 shows the preparation of the excavation column (view in plan); figure 2 is a cross section of the extraction column along the axis of the extraction chamber; figure 3 - the formation of the hydrotransport gap; figure 4 - coal mining in the chamber below its soil; figure 5 - the end of the extraction of coal in the last extraction chamber and preparation for the repayment of drifts; figure 6 is a sequence of mining excavation chambers.

The method can be implemented as follows. In the excavation field of a powerful shallow coal seam of irregular shape with limited reserves (where the use of mechanized complexes is not economically feasible), conveyor 1 (at the lower boundary) and ventilation 2 (along the upper boundary) drifts at the seam roof are carried out at mutually opposite boundaries, and conveyor - in compliance with straightforwardness. Under the conveyor drift, near the formation soil, a hydrotransport drift 3 is carried out with its axis shifted towards the excavation array relative to the axis of the conveyor drift. At the same time, the extraction column is profiled in the extraction field in such a way as to provide gravity flow of coal from the ventilation drift towards the conveyor belt and from the flank of the extraction column to the Bremsberg. The drifts can be fixed with traditional trapezoidal support. On the flank of the extraction column, conveyor 1 and ventilation 2 drifts are shot down by the extraction chamber 4, using a high-performance front-end harvester 5, for example, Joy type, a self-propelled car 6 transporting coal beaten by combine 5, to conveyor drift 1, and a telescopic belt conveyor 7, transporting this coal from the extraction chamber to the Bremsberg. In this case, the chamber 4 can be oriented to the conveyor drift perpendicularly or at an angle (as shown in FIG. 1) for the convenience of entering into the chamber of the self-propelled carriage 6 and the combine 5. The roof of the extraction chamber 4 is supported by an anchor support 8 being erected in the area of the combine 5. During the holding of chamber 4, the working space is ventilated by a local ventilation fan, and after the harvester 5 enters the ventilation drift 2, due to a mine depression according to a countercurrent scheme, i.e. from the conveyor drift 1 through the chamber 4 and further along the ventilation drift 2 in the opposite direction.

After holding the extraction chamber 4, the combine 5 and the self-propelled combine 6 are distilled to a conveyor drift 1, from which the combine 5 is cut into a coal mass, and the extraction chamber 9 is started, leaving a safety pillar of coal between the adjacent extraction chambers approximately equal in width to the width of the extraction chamber 4 The telescopic belt conveyor 7 is shortened. As the extraction chamber 9 is carried out, it is knocked down with the extraction chamber 4 by failures 10, the roof of which is also supported by the anchor support 8, due to which emergency exits are organized and the ventilation reliability is increased.

During the extraction chamber 9 from the hydrotransport drift 3, a well 11 is drilled in a plane passing along the axis of the excavation chamber 4 into the space of this chamber, and a platform 12 with a hydraulic monitor 13 is installed on the soil of the excavation chamber 4. After the hydrotransport drift 3 has failed, the excavation chamber 4 well 11, the drilling rig is dismantled, and the barrel of the hydraulic monitor 13 is directed approximately along the axis of the well 11 and the supply of process water is turned on. With a jet stream, the well 11 is expanded and the platform 12 begins to move with the hydromonitor 13 in the direction of the ventilation drift. Due to the energy of the jet and the movement of the hydromonitor 13 approximately along the axis of the extraction chamber 4, the technological gap 14 is washed to the very soil of the formation.

In the area where the extraction chamber 4 is connected with the ventilation drift 2, the hydromonitor 13 is deployed on the platform 12 and proceed to the extraction of coal below the soil level of the extraction chamber, washing it out as the platform moves, first directly under the extraction chamber and then in the array from the side of the extraction column flank. Due to this, on the one hand, the coefficient of extraction of minerals in a given extraction chamber increases, on the other hand, the degree of controllability of mountain pressure increases due to the deliberate collapse of the roof precisely from the side of the pillar flank. The beaten-off coal in the form of pulp is fed by gravity to the hydrotransport drift 3 through the technological gap 14 and then moves towards the Bremsberg.

In the same manner, coal is taken out under the extraction chamber 9 and in all the others prepared in the extraction field. After the completion of the cleaning work, in all the extraction chambers, coal is excavated under the conveyor drift 1. To do this, on the flank of the column from the hydrotransport drift 3, a well similar to well 11 is drilled into the space of the conveyor drift 1 and a technological gap is drawn from it. On the flank of the conveyor drift, on its soil, a platform 12 with a hydromonitor 13 is installed and work begins on the extraction of coal directly under the drift, followed by leaching of a part of the mineral pillar from the side of the already developed extraction column. At the same time, the shtrekovy lining (if it is not anchor) is also disassembled by a length approximately equal to the effective range of the gyro-jet jet.

During the extraction of coal under the conveyor drift 1, preparations are made for the extraction of coal under the ventilation drift 2. For this, a hydrotransport drift 15 is carried out entirely from the bremsberg towards the flank of the extraction column 15 with an offset of its axis relative to the axis of the ventilation drift towards the worked out space of the extraction column . Further as described above.

When a high-performance mechanical-hydraulic combine equipped with drilling tools for anchoring is available, excavation chambers can be carried out by a mechanical-hydraulic combine, which will allow switching only to hydraulic transport of coal in the area, abandoning a self-propelled car and a belt telescopic conveyor. But then, instead of a straight conveyor drift, a transport drift can be carried out, repeating the contours of the plot with its trajectory, i.e. sinuous, which will further increase the completeness of mineral extraction.

The existing high-performance mobile mechanization tools allow, on the one hand, to quickly carry out excavation chambers and failures and anchor the roof in these workings, i.e. to prepare a work front for hydraulic monitoring excavation; on the other hand, in case of danger, remove expensive equipment from the danger zone.

The use of anchor fastening of the roof of the extraction chambers increases the safety of work not only in the chamber itself, but also on the entire excavation section due to the fact that, in combination with the retention of the roof on the pillars, it allows controlling the rock pressure when the roof collapses when and where it is required.

Drilling a well from a mine near a seam to a mine near its roof allows us to divide in time and in space the methods used to impact the coal mass in order to destroy it. The mechanical impact on the array in this extraction chamber ends with the completion of the drilling of the well, and the hydraulic begins. In this case, the hydraulic effect is exerted on the array only below the soil level of the extraction chamber. Carbon flows from both methods of impact on the array within the excavation section are not mixed.

As the development of treatment works in the excavation area, the degree of danger of their conduct decreases. The developed layer is unloaded from rock pressure, and the treatment works are successively transferred from the more dangerous zone to the less dangerous zone in an advanced manner. Moreover, most of the coal is mined hydraulically, i.e. with the help of hydraulic monitors, and this allows to minimize the number of people in the most dangerous zone.

The combination of mechanical and hydraulic effects on the coal mass in order to destroy it allows you to quickly prepare a treatment front.

Excavation of the bulk of coal by hydraulic means below the soil of the extraction chamber helps to increase not only the efficiency of the development of the formation (several hydromonitors can be installed to increase productivity), but also safety, since people and equipment are in a supported space, and due to the direction of the trunks of the hydromonitors towards the soil formation stability of the roof is not violated.

The above circumstances indicate that the use of this method when excavating powerful shallow formations in areas of irregular shape with limited reserves increases the efficiency and safety of development, that is, to achieve the objective of the invention.

Information sources

1. Zhigalov M.L., Yarunin S.A. Technology, mechanization and organization of underground mining: Textbook. for universities. - M .: Nedra, 1990, p. 388, fig. 353 (a) (analogue).

2. Kodentsov A.Ya. Hydraulic technology in the mines. M .: Nedra, 1984, p. 174-175, Fig. 49 (prototype).

Claims (2)

1. A method of developing a powerful shallow coal seam in irregularly shaped areas, including preparing a mining column by carrying out transport and ventilation drifts, dividing the mining column into strips by excavation chambers, leaving the pillars, drilling wells, coal breaking in the mining chamber, transport of beaten coal for mine workings and management keeping the roof on pillars, characterized in that the ventilation drift is carried out along the upper boundary of the section near the formation roof, the transport drift is also they are drilled at the roof of the formation at the lower boundary of the site in a straightforward manner, under the transport drift near the formation soil, a hydrotransport drift is carried out with a shift of its axis towards the prepared array relative to the axis of the transport drift, excavation chambers are carried out from the transport to the ventilation drift at the formation roof with the erection of anchor support, neighboring extraction chambers are knocked down by failures, from a hydrotransport drift a well is drilled into the space of the extraction chamber in a plane passing along its axis, and provide a section transport flows at the initial stage of the excavation of the chamber below its soil, from the wellhead to the ventilation drift along the axis of the excavation chamber, a hydrotransport slot is cut through the hydraulic jet to the formation soil, and in the opposite direction, coal is removed below the excavation chamber soil and partially under the entire flank side, after coal extraction in the chambers, the pillar is excavated under the transport drift, and then under the ventilation in a similar way. 2. The method according to claim 1, characterized in that the transport and hydrotransport drifts are carried out along the contour of the lower boundary of the site.

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