RU2523246C1 - Coal strip mining - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: proposed method comprises the steps that follow. Top soil layer is removed to be preserves or to be transferred to territories to be reclaimed, loosening, loading and conveying stripped rock to make the waste dumps, dislodging, loading and coal transfer to storage and reclamation of dumps. Note here that seam weathered coal approaching the day surface is extracted and stored separately. Waste dumps are levelled to apply soil and weathered coal layers thereon. Produced layer is loosened with stripped rock and rolled.

EFFECT: higher efficiency.

Description

The present invention relates to mining, in particular to opencast development of a coal deposit and restoration of territories disturbed by opencast mining, and can be used in coal mining and reclamation of waste dumps.

A known method of open coal mining, including the preparation of the earth's surface within the area intended for development; drainage of the quarry field and its protection from water intake; open pit field; conducting stripping operations - excavation and removal of waste rock containing minerals; mining operations - extraction, transportation and unloading of minerals [1]. Open cast mining causes significant harm to the environment, therefore, the lack of work to restore land disturbed by open cast mining is a serious drawback of this method.

The closest analogue, adopted as a prototype, is a method of open-pit coal mining, including: removing the upper soil layer and preserving it or transferring it to territories to be restored; loosening, loading and transportation of overburden with the formation of waste dumps; breaking, loading and transporting coal to a warehouse, as well as reclamation of dumps [2].

The disadvantage of the prototype are:

- weathered coal from the part of the formation leaving under sediments, on the one hand, is a low-quality fuel and its storage in a coal warehouse leads to dilution of commercial coal, on the other hand, it contains humic acids, the introduction of which increases soil fertility;

- the surface area of the waste dump is always greater than the area of the day surface from which the soil layer was removed. Therefore, the volume of the removed soil layer is not enough for the reclamation of all areas disturbed by open work, in particular dumps.

The noted disadvantages reduce the efficiency of the method of open coal mining.

The purpose of the invention is to increase the efficiency of open-pit coal mining by separate coal mining from the weathered part of the formation and placing it on the leveled surface of the rock dump during reclamation.

This goal is achieved by the fact that in the method of open-pit coal mining, including the removal of the upper soil layer and its preservation or transfer to the territory to be restored; loosening, loading and transportation of overburden with the formation of waste dumps;

breaking, loading and transporting coal to a warehouse, as well as reclamation of dumps, according to the technical solution, weathered coal from seams close to the day surface is mined and stored separately, the rock dump is leveled, a layer of soil and weathered coal are applied to the leveled surface, the resulting layer is loosened with overburden rock and roll away.

Near the exit of a coal seam to the surface or under sediment, the elemental composition of coal changes: the carbon and hydrogen contents decrease and the oxygen content increases, humic acids appear. An increase in coal fracture is observed in the weathering zone [3]. The idea is to use weathered coal, which is a low-quality fuel, as a parent component in the restoration of land disturbed by opencast mining. The introduction of the destroyed weathered coal into the overburden rocks will contribute to the formation of humus, and the introduction of this coal into the soil (clay and loamy) improves its structure.

The method can be carried out as follows. In the coal mining region, there are old open-pit coal mining enterprises and new ones are being built. During the construction of a new coal mining enterprise, growing waste dumps appear, which at this stage of the enterprise’s functioning cannot be reclaimed; but the dumps of old coal-mining enterprises require reclamation.

After opening a coal seam, a new enterprise starts mining weathered coal, i.e. development of a part of the formation that is close to the surface or under sediment. This coal is used to restore disturbed lands, in particular to waste dumps of old enterprises. In this case, the waste dumps are leveled with a flattening of its sides, a layer of soil, previously removed from the area of the developed area, and weathered coal are applied to the leveled surface. Then, the resulting layer is loosened to a depth slightly greater than the thickness of the layer, i.e. notched overburden, and slightly rolled away.

By loosening the applied soil layer and weathered coal with an overburden notch, the effect of mixing the soil, coal and overburden rocks is achieved; while coal improves the structure of the soil, enriches it with humic acids, and overburden rocks keep the applied layer from erosion by atmospheric precipitation.

By rolling the applied layer of coal and soil, its erosion is reduced under the influence of wind and precipitation.

Thus, the exclusion of the supply of weathered coal to the finished goods warehouse reduces the likelihood of dilution of coal in the market with low-quality fuel; the application of a layer of weathered coal on the leveled surface of the rock dump contributes to the restoration of land disturbed by open cast mining. All of the above indicates an increase in the efficiency of the open coal mining method, i.e. achieving the objective of the invention.

Information sources

1. Bokiy B.V. Mining engineering. / Textbook for students of mining specialties of universities. - M: Ugletekhizdat. - 1953. - p. 516-518 (analogue).

2. Westcott Paul. Management of open coal mining // [electronic resource]. - Access mode: http://base.safework.ru/ - Access date 02/20/2013 prototype).

3. Lidin G.D. Mining: A terminological dictionary. / G.D. Lidin, P.D. Voronina, D.R. Kaplunov et al. - 4th ed., Rev. and add. - M .: Nedra, 1990, p. 107 (Weathering of coals).

Claims (1)

A method of open-pit coal mining, including the removal of the upper soil layer and its preservation or transfer to the territories to be restored; loosening, loading and transportation of overburden with the formation of waste dumps; breaking, loading and transporting coal to a warehouse; reclamation of dumps, characterized in that the weathered coal of the seams close to the day surface is mined and stored separately, the waste dumps are leveled, a layer of soil and weathered coal are applied to the leveled surface, the resulting layer is loosened with an overburden rock and rolled away.