RU2312219C2 - Method for difficult-to-cave roof preparation for initial caving - Google Patents

Abstract

FIELD: mining, particularly methods of underground or surface mining.

SUBSTANCE: method involves drilling belt entry and air heading; cutting mounting chamber at extraction pillar boundary; installing mechanized complex in the mounting chamber and thawing permafrost roof rock by heat application; breaking roof rock in belt entry and air heading at distance equal to prospective initial roof caving pitch, from extraction pillar boundary along with at least 1.5 times entry and heading section increase; thawing roof rock with air heated by local heater; stacking cut rock in slashing having width determined from section of roof rock to be broken, seam thickness, rock loosening and slashing filling factors.

EFFECT: increased labor safety.

2 dwg

Description

The invention relates to the mining industry and can be used to prepare for the initial landing of perennial frozen roof rocks.

A known method of preparation and control of the primary landing of the roof, including carrying out conveyor and ventilation drifts, driving the mounting chamber and working out the excavation column with a mechanized complex, drilling from the workings of wells into the roof rocks and supplying heat to them. [1] (Prototype.)

The disadvantages of this method are:

- the difficulty of supplying coolant (hot water or steam) to the wells;

- the difficulty of preparing the coolant in the workings;

- a slight halo of thawed rocks around the wells.

The technical task was to create along the mine workings at the site of primary roof collapse longitudinal zones of liberated and thawed rocks, eliminating the jamming of the collapsed roof slab.

The proposed method is characterized in that in the conveyor and ventilation drifts at a distance from the boundary of the extraction column, equal to the expected primary step of the roof collapse, they undermine the roof rocks with an increase in the cross-section of the workings by at least 1.5 times, melt the roof rocks with heated local air heater, and broken rocks are placed in a spreader with a width H, determined from the expression:

where: S _n - the section of the undermined roof rocks, m ² ;

m is the thickness of the reservoir, m;

f _p - coefficient of loosening of rocks;

f _s - the fill factor of the brace.

Introduced in the claims, such an essential feature, as the fact that in the conveyor and ventilation drifts are undermining the roof rocks, can violate the integrity of the rock slab along these workings.

Another significant sign that during the demolition of roofing rocks, the cross section of workings is increased by at least 1.5 times, provides significant exposure of hard-to-break rocks and creates the prerequisites for better thawing of the permafrost massif.

An essential sign that roof rocks are thawed by heated air from a local air heater makes it possible to significantly increase the temperature of mine air, which increases the rate of thawing of the rocks.

An essential sign that the broken rocks are placed in the sparring, avoids the issuance of rocks to the surface.

The next significant sign that the width of the brace is determined from the expression:

ensures that the spacing is sufficient to accommodate the entire broken rock in it.

The proposed method is illustrated by drawings, where Fig. 1 shows in plan a portion of a dredging column prepared for the primary landing of a roof, Fig. 2 is a section AA in Fig. 1.

Symbols adopted in the drawings:

1 - excavation column; 2 - conveyor drift; 3 - ventilation drift; 4 - brace; 5 - local air heater; 6 - thawing halo; 7 - mounting chamber; 8 - treatment plant.

The method is as follows.

When contouring the extraction column 1 with a conveyor drift 2 and a ventilation drift 3 at a distance from the boundary of the extraction column 1, equal to the expected initial step of the roof collapse, the roof is undermined in the conveyor 2 and ventilation 3 drifts, and the broken rocks are placed in the braces 4. Width 4. H) is determined from the expression:

where: S _n - the section of the undermined roof rocks, m ² ;

m is the thickness of the reservoir, m;

f _p - coefficient of loosening of rocks;

f _s - the fill factor of the brace.

At the same time, the cross section of conveyor 2 and ventilation 3 drifts is increased by no less than 1.5 times, and local heaters 5 are installed at the beginning of explosions. An increase in the cross sections of the workings reduces the speed of movement of warm air and improves the conditions of thawing of frozen rocks of the roof to create a thaw aura 6 in an array. At the boundary of the extraction column 1, an assembly chamber 7 is carried out, in which the treatment complex 8 is mounted, and then the treatment works are carried out. The time spent on carrying out conveyor 2 and ventilation 3 drifts, carrying out the mounting chamber 7, installing the treatment complex 8 and the beginning of the cleaning recess is enough to create the necessary thawing halo 6.

Thus, the indicated preparation for the initial planting of hard-to-collapse permafrost rocks can significantly reduce the step of the primary collapse, which will reduce the load on the mechanized lining and avoid air strikes in the mine workings.

The advantages of this method are:

- the creation in the roof along the contouring workings of the disturbed zone and the halo of thawed rocks, which significantly reduces the pitch of the primary landing of the roof;

- Improving safety for miners;

- breakdowns of mechanized roof support are excluded.

Information sources

1. Technological schemes of treatment and preparatory work for the mines of the permafrost region, taking into account the use of systems and means of regulating the thermal regime. M., ed. IGD them. A.A. Skochinsky, - 1987. - S.11-12.

Claims (1)

A method of preparing for the initial landing of a hard-to-collapse roof, including carrying out conveyor and ventilation drifts, sinking the installation chamber at the boundary of the extraction column with the installation of a mechanized complex in it and thawing the perennially frozen roof rocks by thermal exposure, characterized in that in the conveyor and ventilation drifts at a distance from the boundaries of the excavation column, equal to the expected initial step of the collapse of the roof, lead to the undermining of the roof rocks with an increase in the cross section of the workings by at least 1.5 times, stop the roof rocks with heated local air heater, and the broken rocks are placed in a chamfer width H, determined from the expression

where S _n - the section of the undermined roof rocks, m ² ; m is the thickness of the reservoir, m; f _p - coefficient of loosening of rocks; f _Z - the fill factor of the brace.

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