RU2284414C1 - Gently sloping coal bed mining method - Google Patents

Abstract

FIELD: mining, particularly underground mineral bed development.

SUBSTANCE: method involves preparing extraction pillar in accordance with "long pillar along the strike" development system; excavating coal in long breakage face in reverse travel; venting breakage face; controlling mining pressure during roof rock caving in excavated space; accumulating mine water in lower mine points and supplying aqueous antipyrogen solution in goaf. Extraction pillar is profiled along the strike so that the pillar is slightly inclined with respect to horizon line and mine water is discharged in goaf through excavations surrounding the pillar under gravity. The excavation pillar is cut towards pillar top. Water-tight bridges and water accumulation chamber are erected in belt entry at excavation pillar flank. The water accumulation chamber is provided with pumps, pipelines, manometers and shutoff fittings. Excavation pillar bottom is flooded. Mine water is filtered through caved rock and cleaned water is pumped out from water accumulation chamber to day surface.

EFFECT: increased ecological safety of mining works performing.

1 dwg

Description

The invention relates to mining, in particular to methods for developing shallow coal seams according to the development system “Long Poles along strike”, and can be used in the extraction of other formation minerals.

There is a method of developing a shallow coal seam during floor preparation, in which excavation pillars oriented along the strike of the seam are prepared by conveyor and ventilation drifts, the column is mined in reverse, rock pressure is controlled by the complete collapse of the roof in the worked out space, and the working face is ventilated by countercurrent circuit [1]. The disadvantage of this method is that mine water coming from the reservoir and host rocks is collected on a conveyor drift and then goes along inclined workings to the lowest point of the mine — a sump, from where it is pumped to the surface by slurry pumps and sent to treatment facilities (settling tanks). Since sedimentation tanks are inefficient means of cleaning mine water, the burden falls on the environment - nature. At the same time, with an increase in the mine’s productivity for mining, the volume of mine water discharged to the surface increases, thereby increasing the environmental burden on nature.

The prototype is the technical solution closest to the claimed method, in which the extraction pillar is prepared by carrying out conveyor and ventilation drifts, the pillar is worked out in the reverse order, rock pressure is controlled to completely collapse the roof, mine water is collected at the bottom of the shaft and fed into the worked out space [2 ].

The disadvantages of the prototype are:

- mine water treatment has low efficiency, because with an ascending order of mining mining columns, the natural filter (which is the collapsed rocks) does not change and silts over time;

- the extraction column is oriented horizontally, so the method can only be implemented with an upward order of mining extraction columns in the extraction field;

- increased capital costs attributable to the beginning of coal mining, associated with the ascending order of mining columns, requiring a large amount of capital workings before the start of mining;

- the scope of the method is limited to coals that are not prone to spontaneous combustion, since the upper part of the exposed formation may catch fire before it reaches the notch.

The listed disadvantages of the method reduce the efficiency of the development of shallow coal seams and do not allow it to be used to reduce the environmental load on the environment.

The aim of the invention is to increase the efficiency of the development of a shallow coal seam and reduce the negative environmental impact from mining during mining of mineral deposits by profiling the preparation of a mining column and systemic disposal and treatment of mine water by collapsed rocks in the mined-out space.

The systematic drainage and profiling of the excavation column are as follows. After conducting the opening inclined workings, they begin to carry out conveyor and ventilation drifts, the so-called preparing workings, with which the extraction column is prepared. Preparatory workings are carried out on a rise, from flank slopes to the main ones at a certain angle to the horizon. As a result of such profiling of the extraction column in space, mine water coming from the host rocks will be gravity drained from the preparatory face, and when the treatment face is moved in the same manner, water will be discharged into the worked out space, that is, water will not interfere with the treatment and preparatory work. Moreover, as a result of systemic water disposal, all mine water will be collected in a given place, from where it can be conveniently taken with existing means, such as slurry pumps, and used to prepare an aqueous solution of flame retardant.

This goal is achieved by the fact that in the method, including the preparation of the excavation column according to the development system "Long poles along strike", the extraction of coal in the long face of the mine backwind, ventilating the face, controlling rock pressure collapse of the roof in the worked out space, collecting mine water in the lower points of the mine and the supply of an aqueous solution of flame retardant to the worked-out space, the extraction column is profiled along the strike of the formation, preparing it at a slight angle to the horizon, and organizing it about onturivayuschim workings gravity drainage mine water in the goaf, testing of extraction pillar leading in the direction of lift, in the conveyor roadway on the flank extraction pillar and workings lower stope constructing impermeable webs and erecting water collecting chamber, which is equipped with pumps, piping, gauges and valves; the mined-out space of the extraction column is heated, the mine water is filtered by collapsed rocks, and then pumped to the surface by pumps.

The drawing shows a diagram of the preparation of a mining field, explaining a method for developing a shallow coal seam.

The method can be implemented as follows. A flat coal seam is opened by the main conveyor 1 and air supply 2 slopes, and on the flank of the extraction field, by the flank conveyor 3 and ventilation 4 slopes. The extraction column 5 is prepared along the strike of the formation by carrying out conveyor 6 and ventilation 7 drifts at a small (3-5 degrees) angle to the horizon to organize gravity drainage of mine water towards the column flank. The extraction of coal in the column is carried out by a long working face equipped with a mechanized complex 8, a reverse stroke, using a countercurrent ventilation scheme. In the conveyor drift 6, in the area between the ventilation slope 4 of the mounting chamber 9 and in failures 10, water-resistant bridges 11 are erected, thereby organizing a water-collecting chamber 12 in the worked-out space of the worked out extraction column. In the ventilation drift 13, prepared below the extraction column, the pumps 14 of the local drainage system are installed, which are connected by a pipe 15 to the sump on the surface. At the bottom points of the mine (faces of the main and flank slopes), slurry pumps 16 are installed, which are connected by a pipe 17 to the worked out space of the worked column.

Slurry pumps 16 pump contaminated water from the bottom-hole spaces of the main and flank slopes and feed it through the pipe 17 to the worked-out space of the worked column 5. Having passed through the collapsed roofing rocks in the worked-out space of the column 5, as if through a natural filter, the water will be cleaned and enter the drainage chamber 12 , from which pumps 14 through a pipe 15 will be issued to the surface.

As the working face moves, the volume of the catchment chamber will increase, and an increasing amount of collapsed roof rocks will take part in the treatment of mine water.

Due to the profiling of the excavation column at a small angle to the horizon, mine water will always tend to the waste space and will not interfere with the treatment work, and this allows you to organize a descending order of mining extraction columns.

During the mining of the extraction column 5, the next extraction column will be prepared in a similar manner below the dip of the formation, with the transfer of treatment work to which the transfer of work to clean the mine water will be carried out, i.e. the natural filter will be replaced.

Due to the descending order of mining the excavation field, the entire volume of openings is not required, which reduces the capital costs attributable to the beginning of the treatment works, in addition, its reserves will be opened as necessary and therefore the method can be applied on coal seams prone to spontaneous combustion.

The filtering ability of collapsed roofing rocks has long been known. Moreover, in the mines to them. Lenin and them. Kirova (in Kuzbass) in the 80s of the last century, although unintentionally, used this ability to clean mine water in underground conditions.

Thus, the profiling of the extraction columns at a small angle to the horizon and the systemic discharge of mine water into the mined-out space of the extraction column not only leads to an increase in the efficiency of the development of a shallow coal seam, but also to an increase in the efficiency of the treatment of mine water, and therefore to a reduction in the environmental load in the region mining operations.

Information sources

1. Zhigalov M.L. Technology, mechanization and organization of underground mining: Textbook. for universities / M.L. Zhigalov, S.A. Yarunin. - M .: Nedra, p.330, fig.3.30 (analogue).

2. RF patent No. 1121458 A way to reduce the endogenous fire hazard of the worked out space; publ. 10/30/1984. Bull. No. 40 (prototype).

Claims (1)

A method of developing a shallow coal seam, including the preparation of a mining column according to the development system "Long columns along strike", excavation of coal in a long mining face in reverse, airing the mining face, controlling the rock pressure of the collapse of the roof in the mined space, collecting mine water at the lower points of the mine and the supply of an aqueous solution of flame retardant in the developed space, characterized in that the extraction column is profiled along the strike of the formation, preparing it at a slight angle to the horizon, and about gravity drainage of mine water into the mined space is organized by its contouring workings, mining of the extraction column is carried out in the direction of its rise, water-tight bridges are constructed in the conveyor drift on the flank of the mining column and adjacent workings below the bottom face, which is equipped with a drainage chamber, which is equipped with pumps, pipelines, and shutoff valves; the mined-out space of the extraction column is heated, the mine water is filtered by collapsed rocks, and the purified water is pumped out of the catchment chamber by pumps to the surface.