RU2521096C1 - Protection of development entries - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: proposed method comprises mechanised pre-working and stabilisation in coal massif, protection of opened space against adjacent column by coal post. Compensation cavities are made in virgin massif, nearby bed soil, and separated by coal post. Cavities and coal posts there between on massif side and opened space are arranged in staggered manner. Width, height and depth of cavities are defined on the basis of coal seam mining and geological conditions and heading machine performances. Coal post width between compensation cavities is calculated with due allowance for empirical factor equal to 1.3 at working in virgin massif and equal to 1.6 at working in adjacent column abutment pressure zone, seal depth (post height) and seam cubical compression strength.

EFFECT: higher stability of working, lower losses of coal in posts, no need in additional barring.

3 dwg

Description

The invention relates to mining and can be used in underground mining of mineral strata (coal, salt, etc.) at great depths while protecting preparatory workings.

A known method of conducting mining, including the formation of a compensation cavity, drilling blast holes for the entire length of the mine, loading them with explosives (BB) and blasting borehole charges all the way in one go to the compensation cavity (ed. St. USSR N 890794).

The disadvantage of this method is the high complexity and duration of the process of formation of the compensation cavity due to the multi-stage operations consisting in drilling wells and expanding them using the thermal method.

There is a method of conducting uprising mining (ed. Certificate of the USSR N 1004643), including drilling the compensation cavity and blast holes, installing charges in them and simultaneously initiating charges in the compensation and in one blast hole, after which successive short-delayed initiation of explosive charges in the remaining wells.

The disadvantage of this method are: the use of wells of various diameters as explosive and the creation of compensation cavities and, as a result of this, various mining equipment is required for their drilling; the synchronization of explosions of charges located in compensation wells and the first hole is violated due to different detonation speeds (for example, the detonation speed of a detonating cord exceeds 2 times the speed of detonation of an explosive in a hole while initiating them); the use of explosive charges and detonating cords for an explosion in a compensation tank, which increases the cost of implementing the method.

There is a method of protecting preparatory workings during underground mining of mineral strata (Khudin Yu.L., Ustinov MI, Braytsev A.V. et al. “Targetless mining of seams.” M., Nedra, 1983. p. 61), including conducting preparatory mine workings, mining a mineral layer with long mining faces without leaving pillars of minerals between the pillars and guarding the mining workings at the border with the worked-out space by bonfires from roundwood.

The disadvantage of this method is the significant cost of time and material resources for maintaining reused workings

A known method of protecting mine workings (Zaslavsky I.Yu., Kompaniets V.F., Fayvishenko A.G., Kleschenko V.M. Increasing the stability of preparatory workings of coal mines. M., Nedra, 1991. p.20-21), including local preparatory workings that delineate the pillars of the mineral, mining of the pillars of the mineral with long working faces without leaving the pillars of the mineral between the pillars and erection of artificial structures (for example, cast strips made of quick-fire supplying materials, walls made of reinforced concrete blocks, etc.) for the protection of reused areas of preparatory workings.

The disadvantages of this method are the additional material costs of maintaining the workings, as well as the ability to transfer pressure, perceived by artificial structures, to the underlying layers during mining of the formation.

A known method of protecting workings (patent RU No. 2172837 publ. 08/27/2001). This method is adopted as a prototype. The essence of the invention: after the mining face, the side rocks are broken, forming a cross section of the mine, and the broken rock is placed in the worked out space of the formation in the form of a rock strip and in its edge parts adjacent to the walls of the mine are fed under pressure, for example, a fastening solution through perforated pipes .

The disadvantages of this method are: low rates of penetration of the mine, the complication of the passport securing the mine, limited scope, including only layers of thin and medium power.

The technical result of the invention is to increase the stability of the mine, reduce coal losses in the pillars, the exclusion of heaving soil rocks and additional fixing of the mine.

The technical result is achieved by the fact that in the method of protecting the preparatory mine, including mechanized holding and securing the mine in the coal mass, protecting it from the mined space of the adjacent column of whole coal, characterized in that when the mine is being worked in the intact array, compensation cavities are carried out at the formation soil, separated from each other entirely coal, cavities and pillars of coal between them from the side of the array and the mined-out space are arranged relative to each other in a checkerboard pattern, width on, the height and depth of the cavities are determined from the geological conditions of the coal seam and the technical capabilities of the tunneling machine, and the pillars of coal between the compensation cavities are calculated by the formula:

$$B=\frac{qh}{R_0}(\mathrm{one})$$

where q is an empirical coefficient equal to 1.3, - when conducting development in an untouched massif, equal to 1.6, - when conducting development in the zone of influence of reference pressure from an adjacent column; h - reservoir thickness (height of the pillar), m; R ₀ - cubic compressive strength of the formation, MPa

The method is illustrated by figures 1-3, where 1 is a pit, 2 - pillars of coal between the compensation cavities, 3 - compensation cavities, 4 - preparatory development, 5 - coal pillar, 6 - mined out space, 7 - anchor support.

The method allows you to move the maximum reference pressure deep into the array. It is carried out as follows: for the preparation of the excavation column 1, preparatory excavation 4 is carried out, to maintain which a coal pillar 5 is left adjacent to the worked-out space 6. When excavating the excavation, the roof and sides are fastened with anchor support 7, figure 2, 3 according to the calculated passport. Following a lag of 15-20 m using a selective harvester (for example, KP-21), compensation cavities 3 are cut near the formation soil, separated entirely by coal 2. The cavities are staggered relative to each other, the width, height and depth of the cavities are determined from the geological conditions of the coal seam and the technical capabilities of the tunneling machine, (for example, with a coal seam thickness of 5 m and a seam depth of 350-360 m, width a = 1.5 m, height h = 1.5 m, depth L = 2 m), and the pillars of coal between the computer nasational cavities are calculated by the formula 1

Claims (1)

A method for protecting preparatory workings, including mechanized holding and securing the workings in a coal mass, protecting it from the worked out space of an adjacent column of whole coal, characterized in that when working in an untouched mass, compensation cavities are performed at the formation soil, separated from each other entirely from coal, cavities and the pillars of coal between them from the side of the array and the mined-out space are staggered relative to each other, the width, height and depth of the cavities are determined from Horno-geological conditions of occurrence of the coal seam and the technical capabilities of tunneling machine and the coal pillars between the cavities compensation calculated according to the formula:
$$B=\frac{qh}{R_0}(\mathrm{one})$$

where is the width of the pillar of coal between the compensation cavities; q is an empirical coefficient equal to 1.3, - when conducting development in an untouched massif, equal to 1.6, - when conducting development in the zone of influence of reference pressure from an adjacent column; h - reservoir thickness (height of the pillar), m; R ₀ is the cubic compressive strength of the formation, MPa.

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