RU2272136C1 - Development method for thick steep coal bed liable to spontaneous ignition - Google Patents

Abstract

FIELD: mining industry, particularly methods of underground mining.

SUBSTANCE: method involves dividing coal bed into levels by drilling ventilation drifts and entries on upper and lower level boundaries correspondingly; forming sublevel crosscuts and sublevel drifts, which divide levels into sublevels; top-down cutting mineral bed; bypassing caving rock of damaged roof in excavated cavity of sublevels to be treated. The bed is cut without coal pillar establishment between neighboring cavities of adjacent levels. The first to be developed is lower sublevel, which is prepared to development by boring stowing drifts along upper border of above sublevel at bed roof and by boring sublevel drift along lower border thereof at ledge wall of the bed. Lower sublevel is developed in several slices, wherein coal in each slice of sublevel to be stowed is cut by hydraulic monitor to stowing drift to form slide ground surface extending at angle α=45° to rock stratifying plane. Then full filling of excavated cavity is performed within the limits of slices. The excavated cavities are filled with hardening material and the stowing massif is formed as rectangular prism with triangle lying at base thereof. After that level is cut in top-down order beginning from upper sublevel.

EFFECT: reduced coal losses and decreased fire hazard.

1 dwg

Description

The invention relates to mining and can be used in underground mining of powerful steep strata of minerals, mainly coal.

Known methods for developing prone to spontaneous combustion of powerful steep coal seams (A.A. Borisov et al. Technology of underground development of reservoir deposits. M: Nedra, 1972, p.148-176), including carrying out floor drifts dividing the formation into floors. Between floor drifts through a certain distance pass coal-burning furnaces. On the upper boundary of the floor, in a mounting chamber located below the floor ventilation drift, a shield support is mounted. To create a shock-absorbing cushion above the shield support, after the end of its installation, a whole coal is blown up above the mounting chamber. Testing of the prepared column is carried out under the protection of the shield support in the fall in the direction from the recoil to the ventilation drift. Coal breakdown under the shield is carried out using drilling and blasting operations, the beaten-off coal by gravity flows through the coal-blast furnaces to the floor haulage drift. The disadvantages of these methods are the large losses of coal in the pillars left between floors, and the associated increased likelihood of spontaneous combustion of coal in the worked out space and the occurrence of mine fires.

There is a method of developing powerful steep and steeply inclined fire hazardous coal seams (USSR author's certificate No. 1373816, class E 21 C 41/18, 1986). When using this method, the formation is divided into floors by carrying out floor haulage and ventilation drifts, respectively, at the upper and lower boundaries of the floors, leaving behind the pillars of coal. Underfloor drifts are carried out, dividing the floors into sub-floors. Coal is mined in the sub-floors and the rocks are removed, which collapsed earlier during the mining of the upper sub-floors, into the worked-out space of the spent sub-floor.

The disadvantages of this method, adopted as a prototype, are: large losses of coal in the pillars left between floors, and the associated increased likelihood of spontaneous combustion of coal in the worked out space and the occurrence of mine fires; associated with the abandonment of a pillar of coal between floors, the possibility of bypassing earlier fires from higher floors as a result of the intensification of the processes of collapse and displacement as the development of cleaning work in the floor leads to the destruction of the pillar.

The technical result of the proposed method is the elimination of these disadvantages of the prototype, namely the elimination of the bypass of earlier fires from higher floors, which will reduce the fire hazard of the applied technological scheme and eliminate coal losses in the floor.

The technical result is achieved by the fact that in the method of developing prone to spontaneous combustion of powerful steep coal seams, including dividing the seam into floors by conducting floor ventilation and discharge drifts, respectively, at the upper and lower boundaries of the floors, conducting sub-floor cross-valves and sub-floor drifts, dividing floors into sub-floors, mining the mineral layer is carried out in descending order, the collapsed rocks of the roof are passed into the mined-out space of the worked out floors, according to According to the invention, the seam mining is carried out without leaving pillars of coal between adjacent mined spaces of adjacent floors, while the first in the floor is prepared for mining the lower sub-floor by conducting a top-level drift along the top of the seam at the top of the seam and along the lower border of the seam of the seam the drift is worked out by the lower sub-floor by the entry, and coal extraction in the entry of the paved sub-floor is carried out by a hydraulic monitor to the filling drift, forming the surface of the entry soil at an angle α = 45 degrees to the bedding plane of the rocks, the full laying of the worked out space within the boundaries of the entries is made with hardening filling material, while the filling array has the shape of a direct prism, at the base of which lies a triangle, after which the floor is worked out in a descending order, starting from the upper sub-floor.

The implementation of the above set of features allows you to exclude the loss of minerals in the storey pillar, reduce fire hazard.

The essence of the proposed method is illustrated by the diagram shown in the drawing is a transverse section (section in the cross of the reservoir plane), and the following description.

In the drawing

1 - hardening filling material;

2 - formation filling drift;

3 - filling pipe;

4 - sub-floor drifts;

5 - sub-floor crossings;

6 - Georgian walker;

7 - floor haulage cross-section of the worked-out floor;

8 - field floor haulage drift;

9 - inclined floor ventilation cross-section of the worked-out floor;

10 - field floor ventilation drift;

11 - collapsed rocks;

N _e - the height of the worked floor;

h - the inclined height of the sub-floors (except for the lower sub-floor);

h _n - the inclined height of the (lower) sub-floor;

m is the thickness of the reservoir.

A method for developing powerful steep coal seams prone to spontaneous combustion is as follows: the seam is divided into floors by conducting floor drifts 10, 8 and cross-bars 7, 9. Underground cross-floors 5 and sub-floor drifts 4 are used to divide floors into sub-floors. Coal mining within the sub-floors can be carried out by any of the known methods (hydraulic breaking, drilling and blasting using combines, etc.). In the drawing, the breaking of coal is carried out by hydraulic monitors.

The mining of coal seams in the floors is performed in a descending order, without leaving pillars of coal between adjacent mined spaces of adjacent floors, while the first in the floor is prepared for mining the lower sub-floor by carrying out the upper boundary of this sub-floor, at the top of the seam of the stowing drift 2 and along the lower the border at the lying side of the reservoir layer of the sub-floor drift 4 work out the lower sub-floor with openings, and the extraction of coal in the openings of the laid sub-floor is carried out with a hydraulic monitor to the mortgage full-time drift, forming the surface of the entry soil at an angle α = 45 degrees to the bedding plane of the rocks, the full laying of the worked out space within the insertions is made with hardening filling material 1, while the filling array has the shape of a direct prism, at the base of which lies a triangle, after which the floor is worked out produced in a descending order, starting from the upper sub-floor.

Fulfillment of this condition eliminates the bypass of earlier fires from higher floors, which will reduce the fire hazard of the applied technological scheme and eliminate coal losses in the whole storey.

The laying of the developed space of the lower sub-floor adjacent to the floor haulage drift can be done by any of the known methods (pneumatic, hydraulic, etc.). When using technologies with sub-floor hydraulic breakdown, a greater effect is achieved with the hydraulic method of laying.

The backfill array must meet the following basic requirements: to exclude the bypass of previously arising fires and collapsed rocks from the higher floors; reliable isolation of the worked-out space of the spent sub-floors from the penetration of oxygen - air from the worked-out sub-floors into it.

Complete mining of the seam without leaving pillars of coal between the worked-out spaces of adjacent floors allows eliminating one of the main causes of underground fires - spontaneous combustion of coal mass formed in the worked-out space when the pillars of coal are destroyed by rock pressure. Mining the formation without leaving pillars between the worked out spaces of adjacent floors reduces coal losses.

Compared with the prototype, the inventive method eliminates the loss of coal in the inter-floor pillars, eliminates the bypass of previously occurring fires and collapsed rocks from the higher floors, reduces the fire hazard of the applied technological scheme when developing powerful steep coal seams prone to spontaneous combustion.

Claims (1)

A method of developing powerful steep coal seams prone to spontaneous combustion, including dividing the seam into floors by carrying out floor ventilation and recoil drifts respectively at the upper and lower boundaries of the floors, conducting sub-floor cross-ditches and sub-floor drifts dividing floors into sub-floors, mining the mineral layer is carried out in descending order , they let the collapsed roofing rocks into the worked out space of the worked out floors, characterized in that the formation is mined without setting pillars of coal between adjacent mined spaces of adjacent floors, while the first in the floor is prepared for mining the lower sub-floor by conducting a top filling drift at the top of the formation at the top of the formation and a lower sub-floor at the bottom of the bed at the lying side by inserts, moreover, coal extraction in the inserts of the laid sub-floor is carried out by a hydraulic monitor to the filling drift, forming the surface of the entry soil at an angle α = 45 ° to the plane awns bedding rocks complete stowing within zahodok produce hardening stowing pictures, the filling mass is in the shape of a right prism whose base is triangle, whereupon testing of floors in descending order starting from the upper substage.