Method for magnetically controlling phreatic water level during coal mining

Abstract

The present application relates to the technical field of coal mining and discloses a method for magnetically controlling phreatic water level during coal mining. The method comprises: acquiring pre-mining information data; on the basis of a vegetation type and a soil sample from a phreatic layer, determining a vegetation growth range, the vegetation growth range comprising a water table depth range and a soil moisture content range; on the basis of the vegetation growth range and the pre-mining information data, determining the on or off state of a magnetizing device during mining; if the pre-mining water level of the phreatic aquifer is above the upper limit of a water table depth range, controlling the magnetizing device to be turned off and regulating corresponding information data; and if the post-mining water level of the phreatic aquifer is above the regulated water level of the phreatic aquifer, controlling the magnetizing device to be turned on, and regulating the magnetization intensity, so that post-mining information data is within the vegetation growth range. The present application effectively reduces the evaporation of groundwater and the occurrence of regional salinization, and can effectively protect the ecological environment and implement coal mining.

Description

Coal mining phreatic level magnetization control method TECHNICAL FIELD

[0001] The present application relates to the technical field of coal mining, in particular to a coal mining phreatic level magnetization control method. BACKGROUND

[0002] The main area of coal mining in China is in the west. In the early stage of coal mining in the west, the coal seam is shallow and the aquiclude is thin, so coal mining often causes the phreatic level to drop. However, as coal mining in the west extends to the deep part, for example, in a certain mining area, the aquiclude is not completely destroyed, and the overlying phreatic water level drops in the short term but rises later.

[0003] In the phreatic level ecologically sensitive area, changes in the phreatic level can induce ecological degradation. The main method currently adopted is to control the phreatic level through coal mining technology or aquifer management methods. However, the existing technology has the following problems: first, although coal mining technology can achieve the purpose of water conservation, it will lead to a decrease in the development rate of coal resources or be economically unreasonable. Second, the aquifer management method through water pumping and the like has a high cost and pollutes water resources to a certain extent.

[0004] Therefore, how to solve the above problems is crucial for coal mining.

[0005] SUMMARY

[0006] The purpose of the present application is to provide a coal mining phreatic level magnetization control method, which can effectively protect the ecological environment and achieve coal mining.

[0007] To achieve the above purpose, the present application provides the following solutions:

[0008] The coal mining phreatic level magnetization control method is applied to a coal mining phreatic level magnetization control system and includes a water level observer, a magnetization device, a soil moisture content sensor, a transmission module, and an upper computer.

[0009] The water level observer and the magnetization device are both buried in a hydrological observation hole. The hydrological observation hole is opened in the area corresponding to the coal mining face on the ground. The water level observer is used to obtain the water level of the phreatic aquifer.

[0010] The soil moisture content sensor is buried in the root system range of the vegetation on the coal mining face. The soil moisture content sensor is used to obtain the soil moisture content.

[0011] The transmission module is connected with the water level observer, the magnetization device, the soil moisture content sensor, and the upper computer respectively. The upper computer is used to process data according to the information data transmitted by the transmission module and control the on-off of the magnetization device to realize magnetization control. The information data includes the water level of the phreatic aquifer and the soil moisture content.

[0012] The method comprises:

[0013] acquiring pre-mining information data;

[0014] determining a vegetation growth range according to the vegetation type and the phreatic aquifer soil sample; the vegetation growth range comprises a water level depth range and a soil water content range;

[0015] determining a magnetization device on-off state during mining according to the vegetation growth range and the pre-mining information data;

[0016] if the pre-mining phreatic aquifer water level is higher than the upper limit of the water level depth range, controlling the magnetization device to be off, and regulating the corresponding information data;

[0017] if the post-mining phreatic aquifer water level is higher than the regulated phreatic aquifer water level, controlling the magnetization device to be on, and regulating the magnetization intensity so that the post-mining information data is within the vegetation growth range.

[0018] According to the specific embodiments provided in the present application, the following technical effects are disclosed:

[0019] The present application provides a coal mining phreatic level magnetization control method, which magnetizes underground water by setting a magnetization device. Magnetization of underground water within a certain intensity range can reduce surface tension, thereby reducing the upward guide height of the phreatic surface, and effectively reducing the evaporation of underground water and the occurrence of regional salinization. The present application is simple and convenient to operate, consumes low cost, can effectively protect the ecological environment, and has good environmental protection effect. Thus, the ecological environment can be effectively protected, and coal mining can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0021] Fig. 1 is a flowchart of a coal mining phreatic level magnetization control method;

[0022] Fig. 2 is a design concept flowchart of a coal mining phreatic level magnetization control method. DETAILED DESCRIPTION

[0023] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by those of ordinary skill in the art without creative effort should fall into the scope of the present application.

[0024] The above-mentioned purposes, features and advantages of the present application will be more apparent and understandable, and the present application will be described in further detail with reference to the drawings and specific embodiments.

[0025] The coal mining phreatic level magnetization control method provided by the embodiments of the present application is applied to a coal mining phreatic level magnetization control system, and includes a water level observer, a magnetization device, a soil moisture content sensor, a transmission module and an upper computer.

[0026] The water level observer and the magnetization device are both buried in a hydrological observation hole; the hydrological observation hole is opened in a region corresponding to a coal mining face on the ground; and the water level observer is used to obtain a phreatic aquifer water level.

[0027] The soil moisture content sensor is buried in a root system range of vegetation on the coal mining face; and the soil moisture content sensor is used to obtain a soil moisture content.

[0028] The transmission module is connected with the water level observer, the magnetization device, the soil moisture content sensor and the upper computer respectively; the upper computer is used to perform data processing according to information data transmitted by the transmission module, and control the opening and closing of the magnetization device to realize magnetization control; and the information data includes the phreatic aquifer water level and the soil moisture content.

[0029] As shown in FIG. 1, the method includes:

[0030] Step 100: obtaining information data before mining.

[0031] Step 200: determining a vegetation growth range according to a vegetation type and a phreatic layer soil sample; the vegetation growth range includes a water level burial depth range and a soil moisture content range.

[0032] Step 300: determining an opening and closing state of the magnetization device during mining according to the vegetation growth range and the information data before mining.

[0033] Step 400: if the phreatic aquifer water level before mining is higher than an upper limit of the water level burial depth range, controlling the magnetization device to be closed, and regulating corresponding information data.

[0034] Step 500: if the phreatic aquifer water level after mining is higher than the regulated phreatic aquifer water level, controlling the magnetization device to be opened, and regulating a magnetization intensity to make the information data after mining be in the vegetation growth range.

[0035] In practical applications, taking a certain mining area as an example, its three-phase aquitard is relatively thick, but the local groundwater level is shallow. Coal mining did not damage the aquitard, and after a period of decline, the groundwater gradually recovered and further decreased in depth. Surface vegetation degraded due to salinization caused by the shallow groundwater level. To avoid large-scale ecological degradation in the shallow groundwater area, groundwater level magnetization control was implemented, as shown in Figure 2. The control process is as follows:

[0036] Step 1: Before coal mining, hydrological observation wells are opened in the corresponding area on the ground of the coal mining face, and soil samples of the unconfined layer are obtained through the observation wells. A total of 18 hydrological observation wells are opened.

[0037] Step 2: Install water level monitoring sensors in the hydrological observation wells to monitor the water level of the unconfined aquifer.

[0038] Step 3: Install a magnetizing device in the hydrological observation well. The magnetizing device has a switch and can control whether groundwater flows through it. The magnetizing intensity is adjustable, ranging from 0 to 1 Tesla. The magnetizing device used in this case is an electromagnetic type, and the magnetic field strength can be controlled by a switch.

[0039] Step 4: Investigate the vegetation types on the coal mining face and bury soil moisture sensors within the root zone of the vegetation. The number of soil moisture sensors is the same as the number of water level observation sensors, and they are buried within 1 meter of each hydrological observation well. The main vegetation in the area is herbaceous and shrubby, and a total of 18 water level observation sensors are buried.

[0040] Step 5: Based on the soil samples and vegetation types obtained in Step 1 and Step 4, conduct indoor simulation experiments to obtain the suitable water depth range and soil moisture content range for the vegetation to grow. The results show that the water depth range is 1 meter to 4 meters and the soil moisture content is 40% to 90%.

[0041] Step Six: Turn off the magnetization device to prevent groundwater from flowing through it, and then proceed with coal mining. When the water level drops to the suitable growth range determined in Step Five, irrigate the vegetation manually to a soil moisture content range suitable for vegetation growth.

[0042] Step seven, after the water level sensor detects that the water level begins to rise, the magnetization device buried in step three is opened, the magnetic intensity is 20% to 50% of the maximum magnetic intensity of the device when opened, if the monitored soil moisture content is higher than the soil moisture content suitable for the growth of vegetation, the magnetic intensity is increased, if the maximum magnetic intensity still exceeds the soil moisture content suitable for the growth, water is pumped in the hydrological observation hole to lower the water level until the monitored soil moisture content is within the range of the soil moisture content suitable for the growth. In this application, water is pumped in 3 holes of the coal mining face, and the soil moisture content of the remaining 15 holes is controlled within the range of 40% to 90%.

[0043] Step eight, after the coal mining is completed, the extraction of groundwater is reduced, the phreatic level is also controlled, and the surface vegetation does not significantly degrade. Compared with the traditional method, 83.33% of the water pumping holes are reduced, the water pumping amount is reduced, and the surface vegetation does not significantly degrade, achieving the purpose of economic and ecological consideration.

[0044] This application is aimed at the overall water shortage in the west and the final shallow depth of the phreatic level of the coal mining face. In this type of coal mining face, the depth of the phreatic level becomes shallow within a period of time (the phreatic level is recovered for about 1 year after coal mining, then gradually recovers due to coal mining subsidence, the depth of the phreatic level becomes shallow in some areas, which takes several days to several years, but the overall water shortage in the region is slow), the depth of the phreatic level becomes shallow to a certain extent, which will lead to surface salinization and further degradation of vegetation in the region. The phreatic water can be magnetized within a certain intensity range to reduce the surface tension, thereby reducing the upward lift height of the phreatic surface (the reduction is significant, 1 meter or even several meters), thereby effectively reducing the evaporation of groundwater and reducing the occurrence of regional salinization. The position of the phreatic surface plus the lift height is a factor directly affecting the soil moisture content, and the soil moisture content is the key to ultimately determine the growth of vegetation. This application starts from the lift height, the device does not need to do extra work, mainly uses the natural flow of groundwater to carry out magnetization, and the magnetization can be demagnetized within a certain time range, the environmental impact is smaller than the traditional method.

[0045] The technical features of the above embodiments can be combined arbitrarily, in order to make the description concise, not all possible combinations of the technical features in the above embodiments are described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present application.

[0046] In this paper, specific examples are applied to describe the principles and implementation modes of the present application, the above embodiment is only used to help understand the method and core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed. In conclusion, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A method for controlling the magnetization of a coal mining phreatic level, characterized in that, The coal mining phreatic level magnetization control method is applied to a coal mining phreatic level magnetization control system, comprising a water level observer, a magnetization device, a soil moisture content sensor, a transmission module and an upper computer; The water level observer and the magnetization device are both buried in a hydrological observation hole; the hydrological observation hole is arranged in a region corresponding to a coal mining face on the ground; the water level observer is used to obtain a phreatic aquifer water level; The soil moisture content sensor is buried in a range of a plant root system on the coal mining face; the soil moisture content sensor is used to obtain soil moisture content; The transmission module is connected with the water level observer, the magnetization device, the soil moisture content sensor and the upper computer respectively; the upper computer is used to process data according to information data transmitted by the transmission module, and control the magnetization device to be turned on or off to realize magnetization control; the information data comprises the phreatic aquifer water level and the soil moisture content; The method comprises: obtaining information data before mining; determining a plant growth range according to a plant type and a phreatic aquifer soil sample; the plant growth range comprises a water level buried depth range and a soil moisture content range; determining a magnetization device on-off state during mining according to the plant growth range and the information data before mining; if the phreatic aquifer water level before mining is higher than an upper limit of the water level buried depth range, the magnetization device is controlled to be turned off, and corresponding information data is regulated; if the phreatic aquifer water level after mining is higher than the regulated phreatic aquifer water level, the magnetization device is controlled to be turned on, and a magnetization intensity is regulated so that the information data after mining is within the plant growth range.

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