RU2330143C1 - Method of protection of open pits against ground waters - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: method of protection of open pits against ground waters includes excavation of a water collecting trench round the perimeter of the open pit; the trench is connected with a tank provided with a pump installation. Construction of an enclosed system of water intake wells round the open pit in the water-bearing stratum at a distance less than the design depression radius. Creation of a water curtain by delivery of ground waters out of the tank into the water intake wells. Ground waters mixed with fine material is fed into the water intake wells, the mix being prepared in the tank provided with a mixing chamber.

EFFECT: reduction of costs for protection of the open pit due to reduction of the volume of ground waters fed into the water intake tank.

2 dwg

Description

The invention relates to the mining and construction industries and can be used to protect quarries (with the open method of developing mineral deposits) and construction pits from the penetration of underground water into them.

There is a method of protecting quarries (construction pits) from groundwater, based on the creation of a hydraulic curtain (Emelyanov A.V., Kleiman D.B., Stanchenko I.K., Cheltsov I.I. Water reduction in construction. M: Stroyizdat. - 1971. 182 p., S. 164). The essence of this method consists in performing a drainage ditch along the bottom of the quarry, communicating with a catchment equipped with a pumping unit, creating around the quarry at a distance smaller than the estimated radius of depression in the aquifer of the rocks, closed along the contour of the system of water-absorbing wells and creating a hydraulic curtain by supplying water from catchment basin in water-absorbing wells.

The disadvantage of this method is that it is necessary to pump a large amount of groundwater entering the drainage tank, and this leads to high energy costs and, consequently, increases the economic costs of implementing the method.

The invention solves the problem of reducing the economic costs of protecting the quarry by reducing the amount of incoming groundwater into the catchment.

To obtain the necessary technical result in the known method of protecting quarries from groundwater, including performing along the bottom contour of the quarry of a drainage ditch communicating with a reservoir equipped with a pumping unit, equipment around the quarry of a closed system of water-absorbing wells located at a distance less than the estimated radius of depression in the aquifer rocks, and the creation of a hydraulic curtain by supplying groundwater from a reservoir to water-absorbing wells, it is proposed to supply water-absorbing wells groundwater mixture with particulate material, wherein the mixture is prepared in the tank, which equipped with a mixing chamber.

Equipping the reservoir with a mixing chamber, feeding finely dispersed material into the chamber and mixing it with water, followed by feeding the resulting mixture into water-absorbing wells, leads to the deposition of finely dispersed material in the pores of the aquifer of the rocks, which reduces the permeability of the aquifer in the instrument zone of the quarry and reduces the flow of water from the aquifer of the rocks to the quarry, which, in turn, reduces energy costs for pumping water.

The proposed method is illustrated by drawings, where figure 1 shows a vertical section of the side of the quarry, and figure 2 is a diagram of the deposition of finely dispersed material in the pores of the aquiferous rocks.

In the drawings, the following notation:

1 - aquifer of rocks;

2 - a layer of relatively waterproof rocks;

3 - water-absorbing well;

4 - instrument zone of the aquiferous rocks;

5 - groundwater level in the absence of water-absorbing wells;

6 - groundwater level when creating a hydraulic curtain;

7 - board quarry;

8 - pressure pipeline;

9 - a layer of relatively waterproof rocks;

10 - drainage ditch;

11 - pumping unit;

12 - tray;

13 - the bottom of the quarry;

14 - mixing chamber with a dispenser (not shown);

15 - suction pipe;

16 - tank;

17 - particles of the aquifer of the rocks;

18 - particles of finely divided material.

The method is implemented as follows. The aquifer 1 is located between the layers 2 and 9 of the rocks, which are relative water resistant. A drainage ditch 10 with a reservoir 16 and a pumping unit 11 is arranged along the contour of the bottom 13 of the quarry (Fig. 1). The reservoir 16 is equipped with a mixing chamber 14 and a tray 12 that allows water to be supplied from the drainage ditch 10 directly to the mixing chamber 14, into which through a dispenser ( not shown) finely dispersed material. After mixing finely dispersed material with water, the resulting mixture is fed through a suction pipe 8 to water-absorbing wells 3, equipped in the aquifer 1 of the rocks and located around the quarry at a distance less than the estimated radius R of the depression.

The suction pipe 15 is configured to supply water both from the mixing chamber 14 and from the reservoir 16. After injection into the wells 3, particles 18 of finely dispersed material together with water penetrate into the pores between the particles 17 of the aquifer 1 of the rocks and are deposited therein. The precipitation of particles 18 of finely dispersed material occurs mainly in the instrument zone 4 of the aquifer 1 below the groundwater level 6, which is established when water is supplied to the wells above the initial level 5 (in the absence of a hydraulic suspension).

As a result of the deposition of particles 18 of finely dispersed material between particles 17 of the aquifer of the rocks, the permeability of this layer decreases and the influx of water into the quarry and the energy consumption for pumping water are reduced.

A specific example of the method. At the opening of the amber deposit, an open-cast sand-gravel layer of 1 rocks was exposed by a quarry. To protect the quarry from the influx of water, a hydraulic curtain method was used. In the quarry, a drainage ditch 10 was equipped along the bottom contour 13, with a reservoir 16 and a mixing chamber 14 with a tray 12, as well as a pumping unit 11.

Finely dispersed material (sapropel of the bottom sediments of lakes obtained by cleaning them) was fed into the mixing chamber 14, and the resulting mixture was pumped by installation 11 through pipeline 8 into water-absorbing wells 8 of a hydraulic curtain, equipped in a sand and gravel layer 1 at a distance of 120 m from the contour of the bottom of the quarry (estimated depression radius of 700 m, see the Handbook of hydraulic calculations. Edited by P.G. Kiselev. Ed. 4th revised and enlarged M .: "Energy", 1972. - 312 p., p.213) .

When the mixture was injected into wells 3, particles of sapropel 18 penetrated into the pores of the sand-gravel layer 1 and precipitated between the particles 17 of this layer. As a result, after 2.5 months of supplying finely dispersed material into the aquifer sand and gravel layer, its permeability decreased by about 8 times, accordingly, water inflow (from 250 to 30 m ³ / h) into the quarry decreased and energy costs for pumping water from the quarry decreased.

Claims (1)

A method of protecting quarries from groundwater, including performing along the bottom contour of the quarry a drainage ditch communicating with a tank equipped with a pumping unit, equipment around the quarry of a closed system of water-absorbing wells located at a distance less than the estimated depression radius in the aquifer of rocks, and creating a hydraulic curtain by feeding groundwater from the reservoir to the water-absorbing wells, characterized in that a mixture of groundwater with finely divided material is supplied to the water-absorbing wells, the mixture is prepared in a tank, which is equipped with a mixing chamber.

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