RU2498065C1 - Method to mine mineral beds - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: method to mine mineral beds includes separation of a mined area of a mine field into mineral columns, preparation of columns by means of arrangement of area developing entries, working of columns with longwall faces equipped with mechanised complexes and dismantling of mechanised complexes in dismantling chambers after completion of actual mining in the longwall faces. If a distance between the longwall face and the location of the dismantling chamber is more than the width of the zone of high stresses that arise in front of the longwall face bottom, at the border of the mined column in front of the longwall face bottom they drive an auxiliary dismantling mine. The bed is loosened in the area that adjoins the auxiliary dismantling mine at the side of the longwall face, by means of drilling of wells in the bed. Actual mining in the longwall face is continued until the auxiliary dismantling mine is stripped with its bottomhole. At the same time the width of the zone of loosened bed in the area that adjoins the auxiliary dismantling mine at the side of the longwall face is determined from the following expression.

EFFECT: reduced costs related to dismantling of a mechanised complex, reduction of time to perform dismantling works and their increased safety.

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Description

The invention relates to mining and can be used in underground mining of mineral deposits by lavas equipped with treatment mechanized complexes.

There is a method of underground mining of mineral strata (Auth. Certificate. RU No. 1434109, publ. Bull. 40, 1988), including the separation of the mine section of the mine field into mineral columns (longer columns), the processing of which is carried out by lavas. To prepare the pillars for excavation, preparatory workings take place. After completion of the pillar mining, the treatment equipment is dismantled in the dismantling furnace.

The disadvantages of this method are the significant cost of dismantling, the long duration of their implementation and the increased risk of labor for miners associated with an increased degree of destruction of roofing rocks and rock outfalls in dismantling chambers.

A known method of developing mineral deposits using mechanized complexes (Patent RU No. 2101497, publ. 10.01.1998), adopted as a prototype method. This method includes dividing the worked out section of the mine field into poles, preparing the pillars by carrying out preparatory workings and mining the pillars with lavas equipped with mechanized complexes. After the cessation of lavage in lavas, the mechanized complexes are dismantled in the dismantling chambers.

The disadvantages of this method are the long duration of the dismantling work and their increased danger.

The technical result of the proposed method is to reduce the duration of the dismantling work and increase their safety.

The technical result is achieved by the fact that in the method of developing mineral strata, including the separation of the mine section of the mine field into mineral columns, the preparation of pillars by conducting preparatory mine workings, the mining of pillars with lavas equipped with mechanized complexes and the dismantling of mechanized complexes in dismantling chambers after termination in lavas treatment works, with the distance between the lava and the location of the dismantling chamber greater than the width of the zone increased x stresses that occur in front of the face of the lava, at the boundary of the worked column ahead of the face of the lava, auxiliary dismantling work out, weaken the formation in the area adjacent to the auxiliary dismantling work on the side of the lava, for example, by drilling along the formation of wells, treatment work in the lava continues to opening it with the bottom of the auxiliary dismantling mine, while the width of the zone of the weakened formation in the area adjacent to the auxiliary dismantling mine from the side of the lava is determined from the expression

l≥c- a ,

where: l is the width of the zone of the weakened formation, m;

c is the width of the dismantling chamber, m;

a - the width of the auxiliary dismantling workings, m

The essence of the proposed method for the development of powerful layers of minerals is illustrated by the schemes presented in figure 1 and figure 2.

Figure 1 shows a diagram explaining: the location of the auxiliary dismantling excavation relative to the face of the lava; the location of the zone of the weakened formation relative to the auxiliary dismantling; the nature of the change in increased stresses in the zone of reference pressure in front of the face of the lava.

Figure 2 shows a diagram explaining the location of the mechanized lining in the dismantling chamber after opening by the face of the lava auxiliary dismantling workings.

Figure 1-2: 1 - the face of the lava; 2 - mechanized support; 3 - auxiliary dismantling; 4 - plot of increased stresses arising in front of the face of the lava; 5 - well; L is the width of the zone of increased stress arising in front of the face of the lava; a - the width of the auxiliary dismantling workings; b is the width of the bottomhole space of the lava: l is the width of the zone of the weakened formation; c is the width of the dismantling chamber.

The disadvantages of the known methods are largely due to the high degree of destruction of the rocks of the immediate roof of the reservoir located above the dismantling chamber, and the collapse of the roof rocks (collapses) during dismantling. The destruction of the rocks of the immediate roof occurs as a result of exposure to increased stresses in the zone of reference pressure, which forms in front of the face of the lava. As a rule, when using the known prototype method, the prevention of roof rock collapse and ensuring the safety of mining in dismantling chambers is impossible without additional support.

The inventive method is as follows. The worked out section of the mine field is divided into poles. Pillars are prepared for development by conducting preparatory workings. Pillars are worked out by lavas equipped with mechanized complexes.

When the distance S between the lava and the location of the dismantling chamber is greater than the width of the zone of increased stress L arising in front of the face of the lava, auxiliary dismantling work out at the boundary of the worked column ahead of the face of the lava 3. The formation is weakened in the area adjacent to the auxiliary dismantling work from the side lava, for example, by drilling through a wellbore 5. Weakening of the formation can also be accomplished by other known methods: by creating cracks in the formation, by blasting in the formation flight charges, fracturing the formation, and others.

The width of the zone of the weakened formation (l) is determined from the expression

l≥c- a ,

where: c is the width of the dismantling chamber;

a is the width of the auxiliary dismantling excavation.

Treatment work in the lava continues until it is opened by the face of the auxiliary dismantling mine. After the cessation of lavatory work in the lava, the mechanized complexes are dismantled in a dismantling chamber of width c = a + b (Fig. 2).

The penetration of auxiliary dismantling excavation 3 at a distance S (Fig. 1) greater than the width of the zone of high rock pressure L, and the weakening of the reservoir in the area adjacent to the auxiliary dismantling excavation from the side of the lava, can reduce the negative impact of increased stresses arising in front of the face of the lava on rocks of the immediate roof located above the dismantling chamber. Above the zone of the weakened layer, the rocks of the immediate roof are unloaded from dangerous stresses and fall almost without significant damage. Such a positive effect when the formation is weakened by drilling wells on it is provided due to the destruction of the inter-pillar pillars.

When the condition l≥c- a is fulfilled, unloading from elevated stresses of the rocks of the immediate roof located above the mechanized support after opening the auxiliary dismantling mine by the face of the lava is ensured.

Improving the condition of the rocks of the immediate roof in the dismantling chamber, and therefore increasing their maximum permissible exposures, can reduce the costs associated with dismantling the mechanized complex, reduce the duration of dismantling work and increase the safety of miners. Reducing the duration of the dismantling works is also achieved due to the anticipatory implementation of auxiliary dismantling workings 3, which eliminates the need to expand the bottomhole space of the lava to the size of the dismantling chamber after the cessation of treatment in the lava. So, when developing powerful seams using the known method, the prototype, after cessation of lava treatment in the lava, the bottomhole space of the lava is usually expanded to the dimensions of the dismantling chamber by excavating coal ahead of the face of the lava, for example, roadheaders.

The parameters necessary for the implementation of the proposed method (the width of the zone of increased stresses that occur in front of the face of the lava, the width of the dismantling chamber, the width of the auxiliary dismantling excavation) are determined in each case by using well-known methods of mine, laboratory or analytical studies taking into account specific mining and geological and mining conditions for the development of a mineral reservoir.

The maximum effect when using the proposed method is achieved when mining powerful (more than 3.5 m) layers of minerals in the immediate roof of which rocks with relatively low strength characteristics lie. With increasing depth of mining operations, the effectiveness of the use of the proposed method increases.

Claims (1)

A method of developing mineral strata, including dividing a mined area of a mine field into mineral posts, preparing columns by conducting preparatory workings, mining columns with lavas equipped with mechanized complexes, and dismantling mechanized complexes in dismantling chambers after the cessation of lavage operations in lavas, characterized in that when the distance between the lava and the location of the dismantling chamber is greater than the width of the zone of increased stresses arising x ahead of the face of the lava, on the boundary of the worked column ahead of the face of the lava, auxiliary dismantling work out, weaken the formation in the area adjacent to the auxiliary dismantling work on the side of the lava, for example, by drilling along the formation of wells, treatment work in the lava continues until it is opened by the face auxiliary dismantling workings, while the width of the zone of the weakened formation in the area adjacent to the auxiliary dismantling workings from the side of the lava, is determined from the expression
l≥ca
where l is the width of the zone of the weakened formation, m;
c is the width of the dismantling chamber, m;
a - the width of the auxiliary dismantling workings, m

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