RU2014474C1 - Method for reducing pollution of mine water - Google Patents

Abstract

FIELD: reducing pollution of mine water. SUBSTANCE: method involves determining points of inflow of underground water, drilling uprising drain holes at an angle of 30± 10^° to prevailing open fissures of water-bearing horizon, setting up casing pipes, installing hydraulic check valves and pressure gauge and connecting to the hole a pipe for delivery of underground water into cleaning facilities or water receivers. Water is taken from water receivers not later than 2 h after their filling. EFFECT: reduction of oxidizing processes achieved by limiting the time of effect of mine medium on underground water entering the mine. 2 cl

Description

 The invention relates to mining, mainly to the coal industry.

 The goal is to reduce oxidative processes in mine water by limiting the time that the mine environment affects groundwater.

 A known method of reducing pollution of mine water by creating a group of sumps for several mines, where the path of movement of mine water is many times increased, which contributes to the deposition of suspended matter [1].

 The closest in technical essence to the proposed one is a method of reducing the volume of mine water by preliminary dewatering by laying wells from underground workings and separately issuing drainage and mine water [2].

 The disadvantage of this method is the fact that it does not exclude the communication of drainage water with the mine atmosphere and the soil of the workings, and this contributes for a short time to an increase in the mineral component of the pollution (decrease in pH, increase in solids, etc.). Reducing the path of water movement is achieved by drilling new wells and building new water collectors and new pumping stations, which is laborious, expensive and time-consuming.

Many mines are characterized by the presence of thionic bacteria, many times accelerating the process of acid formation in mine water due to the oxidation of FeS ₂ iron disulfides, which are present in large volumes in coal and host rocks. Under these conditions, drainage water, in contact with the mine workings and mine atmosphere, changes in quality, become more mineralized and acidic.

 The essence of the proposed technical solution consists in transferring groundwater to an isolated pipeline system and supplying it directly to treatment facilities or water collectors without contact with the soil of the mine workings and the mine atmosphere.

 The method is as follows. Determine where the groundwater inflows in the mine, conduct water analyzes, compare the analysis results with the water analyzes in the mine’s main water collector, make sure that the underground waters had a neutral or slightly alkaline environment (pH 7–9) at the moment they entered the mine, which is typical, for example, for the East Donbass, and a dry residue of 1-2 g / l. In other words, the quality of groundwater is close (or corresponds) to the standards of drinking water supply.

 Make sure that water enters the main water collector of the mine (in the sewage treatment plant), for example, with an acidic medium (pH 3.5) and a dry residue of up to 8 g / l.

Determine the position of the aquifers, where is the flow of water into the mine and draining rise drilled boreholes at an angle ^of 20-40 to the prevailing open fracture aquifer. Equip boreholes with casing and insulating devices, connect a hydraulic valve and a manometer. The flow rate of the wells is sequentially measured and the operational reserves of groundwater are determined, the valve position is adjusted so that the flow rate of the well is less than the reserves, this ensures, taking into account seasonal fluctuations in resources, the protection of aquifers from premature depletion and, thus, the stable functioning of this water intake in for a long time with constant water quality, and this is necessary to ensure a stable operation of treatment facilities.

The coefficient K to reduce water flow in the well is determined by the formula
K = K ₁ xK ₂ , where K ₁ is the coefficient of decrease in the resources of aquifers in the autumn-winter period (for the East Donbass it was calculated from long-term observations and amounts to 0.89);
K ₂ - coefficient taking into account the need for replenishment of reserves depending on the ratio of the throughput of the drainage system of a given well Q m ³ / h and operational reserves of the aquifer Q _e m ³ / h.

≥ 1 коэффициент К₂ может быть принят равным 1.With the ratio

≥ 1, the coefficient K ₂ can be taken equal to 1.

< 1 коэффициент К₂ принимается в пределах 0,9-0,95. Смысл применения данного коэффициент заключается в резервировании 5-10% притока для поддерживания запасов на определенном, не подлежащем снижению уровня.With the ratio

<1 coefficient K _{2 is} accepted in the range of 0.9-0.95. The meaning of applying this coefficient is to reserve 5-10% of the inflow to maintain reserves at a certain level that cannot be reduced.

 With steady pressure, a larger coefficient is applied.

, м³/ч, где b - диаметр труб системы, м;
Н - высота водяного столба (напор) в скважине, м;
L - длина скважины, м;
g - ускорение свободного падения 9,8 м/c².The capacity of the drainage system can be determined by the well-known formula:
Q = 4 · 10 ³ · b

, m ³ / h, where b is the diameter of the pipes of the system, m;
N - the height of the water column (pressure) in the well, m;
L is the length of the well, m;
g - acceleration of gravity 9.8 m / s ² .

 After determining the coefficient K and controlling the flow rate using a hydraulic valve, a pipeline is connected to the well through which underground water, isolated from the mine atmosphere and mine workings soil, is transferred directly to treatment facilities or a catchment. If there are thionic bacteria in the mine, the water becomes mine for a short time. It was also established that changes in the properties of water (smell, color, taste, etc.) change after 2 hours after sampling, so the residence time of isolated groundwater in the catchment should be limited to 2 hours, after which the effectiveness of the proposed method will decrease.

 At the same time, subject to this condition, experience shows that the effectiveness of the method is very high.

 The method also makes it possible to dilute brines falling into the mine due to, for example, attracting non-drained freshwater reserves occurring at shallow depths.

Claims (2)

1. METHOD FOR REDUCING MINE WATER POLLUTIONS, including drilling of rising wells into aquifers at water supply sites, drainage of water from aquifers through wells, transfer of mine water from sources to water collectors or treatment facilities, and shortening of the path of mine water through mine workings, differing the fact that in order to reduce oxidative processes in mine water by limiting the time of exposure of the mine environment to the water coming from aquifers in rising drilling wells In important areas, insulating plugs are installed, connected to the casing pipes, equipping the wells with a hydraulic valve and a manometer, and connecting the casing strings to the insulated pipelines, which are installed in the mine workings, determine the aquifer reserves, compare them with the capacity of the well-pipeline system and transfer water from the risers through an isolated pipeline into the catchment or treatment facilities, while the wells are drilled at an angle of (30 ± 10) ^o to the strike of the prevailing open fracture ty of the aquifer, and the water flow rate is established in compliance with the conditions for the protection of aquifers from depletion.  2. The method according to claim 1, characterized in that when the water is supplied from the aquifer through the pipeline, the time spent by the underground water in the catchment is set to no more than 2 hours.