CN115404915A - Underground water pollution prevention and control method for ionic rare earth mining process - Google Patents
Underground water pollution prevention and control method for ionic rare earth mining process Download PDFInfo
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- CN115404915A CN115404915A CN202211079755.6A CN202211079755A CN115404915A CN 115404915 A CN115404915 A CN 115404915A CN 202211079755 A CN202211079755 A CN 202211079755A CN 115404915 A CN115404915 A CN 115404915A
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- 238000000034 method Methods 0.000 title claims abstract description 74
- 238000005065 mining Methods 0.000 title claims abstract description 46
- 230000008569 process Effects 0.000 title claims abstract description 40
- 229910052761 rare earth metal Inorganic materials 0.000 title claims abstract description 39
- 150000002910 rare earth metals Chemical class 0.000 title claims abstract description 39
- 230000002265 prevention Effects 0.000 title claims abstract description 9
- 238000003911 water pollution Methods 0.000 title description 7
- 230000008014 freezing Effects 0.000 claims abstract description 74
- 238000007710 freezing Methods 0.000 claims abstract description 74
- 230000004888 barrier function Effects 0.000 claims abstract description 71
- 239000012530 fluid Substances 0.000 claims abstract description 30
- 239000002689 soil Substances 0.000 claims abstract description 23
- 238000003895 groundwater pollution Methods 0.000 claims abstract description 9
- 239000011159 matrix material Substances 0.000 claims abstract description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 20
- 238000012544 monitoring process Methods 0.000 claims description 12
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- 238000002386 leaching Methods 0.000 claims description 10
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 7
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 6
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 claims description 6
- -1 freon Chemical compound 0.000 claims description 5
- 230000017525 heat dissipation Effects 0.000 claims description 5
- 239000004927 clay Substances 0.000 claims description 4
- 239000011435 rock Substances 0.000 claims description 4
- 229910021529 ammonia Inorganic materials 0.000 claims description 3
- 239000003795 chemical substances by application Substances 0.000 claims description 3
- 239000001294 propane Substances 0.000 claims description 3
- 239000004576 sand Substances 0.000 claims description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 2
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- 238000007792 addition Methods 0.000 description 1
- 239000012080 ambient air Substances 0.000 description 1
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 1
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 1
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D31/00—Protective arrangements for foundations or foundation structures; Ground foundation measures for protecting the soil or the subsoil water, e.g. preventing or counteracting oil pollution
- E02D31/002—Ground foundation measures for protecting the soil or subsoil water, e.g. preventing or counteracting oil pollution
- E02D31/004—Sealing liners
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D19/00—Keeping dry foundation sites or other areas in the ground
- E02D19/06—Restraining of underground water
- E02D19/12—Restraining of underground water by damming or interrupting the passage of underground water
- E02D19/14—Restraining of underground water by damming or interrupting the passage of underground water by freezing the soil
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/28—Dissolving minerals other than hydrocarbons, e.g. by an alkaline or acid leaching agent
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
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- General Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Geology (AREA)
- Paleontology (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
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Abstract
The application discloses a method for preventing and controlling groundwater pollution in an ionic rare earth mining process, belongs to the technical field of mining, and solves the problem that in the prior art, the peripheral environment is irreversibly changed by seepage prevention means such as seepage prevention curtains and seepage prevention cloth in the ionic rare earth mining process. The technical scheme of the application comprises the following steps: according to geological conditions and ore deposit distribution of a rare earth mining area, thermosiphons are distributed in a freezing barrier area needing to be frozen, and two adjacent thermosiphons are arranged at intervals; injecting a working fluid medium into the thermosiphon tube; freezing the matrix around the deposit by a thermosiphon and forming a frozen soil type freezing barrier; the temperature of the thermosiphon and its surrounding matrix is monitored to maintain the integrity of the freeze soil type freezing barrier. The application has the advantages that: a complete freezing barrier is formed at the edge of the production zone, preventing the seepage of contaminants and not causing irreversible changes to the surrounding environment.
Description
Technical Field
The invention relates to a method for preventing and controlling underground water pollution in an ionic rare earth mining process, belonging to the technical field of mining.
Background
The ionic rare earth mining process in China mainly comprises the following steps: an in-situ leaching process, a heap leaching process, and an in-situ leaching process. The in-situ leaching process generally recovers the mother liquor through a liquor collection system, i.e., a liquor collection ditch. Compared with the former two processes, the in-situ leaching process has the advantages of not damaging vegetation on the surface of a mining area, not generating tailings, not digging raw ores, reducing water and soil loss of the mining area, changing topography and the like. However, in the process of exchanging the prepared ammonium sulfate solution injected into the ore body through the injection well, the residual solution and the heavy metal elements acted by ammonium ions inevitably pollute the surrounding underground water resources through the osmosis.
In view of the situation, most of the prior art is to improve the liquid collection efficiency as much as possible in the liquid collection engineering part, but because of the special mineralization position and geological features of the ionic rare earth ore, the upper part and the bottom of the ore-containing layer of the ionic rare earth ore are mostly water-tight claystone (water-tight top plate and water-tight bottom plate), the ore-containing layer is permeable sandstone, and after the leaching solution is injected, the mother solution and the waste liquid are bound to seep out from the sandstone of the ore-containing layer, thereby polluting the surrounding environment. Although ammonia nitrogen and heavy metal elements in the polluted soil and underground water can be removed by chemical means in the later period, the removal effect is not good enough, and the ammonia nitrogen and the heavy metal elements cannot be completely removed.
Some anti-seepage means have appeared in the prior art, such as the manufacture of anti-seepage curtains, anti-seepage cloths for mine areas by grouting, but they inevitably cause irreversible changes to the surrounding environment. And a complete barrier cannot be formed on the lower part of the whole mining area under the condition of low cost, most of the barrier is arranged in a partial bedrock fracture zone, and partial anti-seepage measures are mainly focused on the anti-seepage treatment of a liquid collecting ditch and a liquid collecting pool of mother liquid without considering the mining area.
Disclosure of Invention
Aiming at the problem of the ecological environment of the mining area in the in-situ leaching mining of the ionic rare earth ore in the prior art, the invention provides the underground water pollution prevention and control method for the ionic rare earth mining process, which forms a complete freezing barrier at the edge of the mining area to prevent the seepage of pollutants.
In order to solve the technical problems, the technical scheme adopted by the invention is that the method for preventing and controlling the pollution of the underground water in the ionic rare earth mining process comprises the following steps:
s1) surveying geological conditions and deposit distribution of a rare earth mining area, and determining the position and the shape of a freezing barrier;
s2) according to the position and the shape of the freezing barrier, thermosiphons are distributed in the region of the freezing barrier needing to be frozen, and the two adjacent thermosiphons are arranged at intervals;
s3) injecting a working fluid medium into the thermosiphon; freezing the matrix around the deposit by a thermosiphon and forming a frozen earth type freezing barrier;
s4) monitoring the temperature of the thermosiphon and the surrounding matrix thereof to keep the integrity of the frozen soil type freezing barrier.
Preferably, the method for preventing and controlling the groundwater pollution in the ionic rare earth mining process comprises the steps that the freezing barrier is annularly arranged around the ore deposit, a waterproof bottom plate formed by claystone is arranged below the ore deposit, a waterproof top plate formed by claystone is arranged above the ore deposit, the upper end of the freezing barrier penetrates through the waterproof top plate, and the lower end of the freezing barrier extends into the waterproof bottom plate formed by claystone; the ore deposit is located in the area enclosed by the waterproof bottom plate, the waterproof top plate and the freezing barrier.
Preferably, in the method for preventing and controlling the underground water pollution in the ionic rare earth mining process, the thermosiphon is a linear thermosiphon; in the step S2), a plurality of drilling positions are selected in a freezing barrier area needing freezing, a vertical shaft used for placing a linear thermosiphon is drilled at the drilling positions, a waterproof top plate formed by the clay rock above the ore deposit penetrates through the vertical shaft, and a waterproof bottom plate formed by the clay rock below the ore deposit penetrates through the lower end of the vertical shaft.
Optimally, in the method for preventing and controlling the underground water pollution in the ionic rare earth mining process, the drilling depth of the vertical shaft is 10-20 cm greater than the length of the linear thermosiphon to be buried; the diameter of the formed hole of the vertical shaft is more than or equal to 1.5 times of the diameter of the linear thermosiphon; the heat dissipation section at the upper part of the linear thermosiphon is higher than the opening at the end part of the vertical shaft, and the gap between the linear thermosiphon and the vertical shaft is filled with fine sand.
Optimally, the method for preventing and controlling the underground water pollution of the ionic rare earth mining process is characterized in that the interior of the thermosiphon is filled with working fluid; the thermosiphon is connected with a refrigerating unit and a circulating pipeline, the thermosiphon is connected with the refrigerating unit through the circulating pipeline, and the refrigerating unit circulates working fluid in the thermosiphon through the circulating pipeline; the working fluid includes ammonia, freon, carbon silica, propane, and the like.
Optimally, the control end of the refrigerating unit is connected with a control system, and the control system controls the refrigerating unit to carry out active circulation and passive circulation;
when the control system controls the refrigerating unit to perform active circulation, the control system opens an active refrigerating device of the refrigerating unit, and the active refrigerating device circulates the working fluid in the thermosiphon pipe;
when the control system controls the refrigerating unit to carry out active circulation, the control system closes the active refrigerating equipment of the refrigerating unit, and the working fluid is circulated by utilizing the relatively high temperature in the external cold air and the soil.
Optimally, the method for preventing and controlling the groundwater pollution in the ionic rare earth mining process comprises the steps of arranging a plurality of water quality monitoring wells at the periphery of a freezing barrier area; in the process of rare earth mining, the concentration of a leaching agent in water quality in a water quality monitoring well is monitored.
Optimally, in the method for preventing and controlling the groundwater pollution in the ionic rare earth mining process, in the step S2), according to the shape and the position of the freezing barrier, temperature sensors are arranged at all parts of the thermosiphon and are connected with a control system; the temperature sensor monitors whether the temperature of each part of the thermosiphon is below the freezing point.
The beneficial effect of this application does: the freezing barrier can be applied to shallow soil or the depths of thousands of meters, can effectively perform anti-seepage treatment on rare earth deposits of different depths, and has a wide application range.
By adopting the freezing barrier, the radioactive nuclide or most other chemical, biological, liquid or solid can be isolated, so that the pollutants are prevented from permeating into the surrounding environment, and the environmental hazard of exploitation is reduced.
Is environmentally friendly and produces little hazardous waste during freeze barrier formation and maintenance. And the freezing barrier can be maintained and used continuously, the life cycle is long, the operation cost is low, and the like.
Based on the moisture in the soil body, water does not need to be injected into the soil body basically when the water-saving soil-filling device is used, and the water-saving soil-filling device is convenient and quick to install and operate and flexible to use.
Drawings
FIG. 1 is a schematic diagram illustrating the method for preventing and controlling groundwater pollution in the ionic rare earth mining process according to the present application;
FIG. 2 is a schematic top view of the groundwater pollution prevention and control method in the ionic rare earth mining process according to the present application;
fig. 3 is a schematic view of the thermosiphon of the present application.
The system comprises a linear thermosiphon 1, a refrigerating unit 2, a circulating pipeline 3, a control system 4, an ore deposit 5, a freezing barrier 6, a temperature sensor 7, a water quality monitoring well 8, a pumping hole 9, a water-resisting top plate 10 and a water-resisting bottom plate 11.
Detailed Description
The technical features of the present invention will be further explained with reference to the accompanying drawings and specific embodiments.
As shown in figures 1 and 2, the invention is a groundwater pollution prevention and control method for ionic rare earth mining process, which adopts the technical scheme that a thermal siphon is used for forming a freezing barrier (6), and the freezing barrier (6) is used for isolating a rare earth deposit (5) during mining of the ionic mining rare earth deposit (5) through a pumping hole (9). The method for preventing and controlling the pollution of the underground water in the ionic rare earth mining process needs to be realized by a freezing barrier generation system.
In the example, the freezing barrier generation system comprises a plurality of thermosiphons, a refrigerating unit (2), a circulating pipeline (3) and a control system (4); the circulating pipeline (3) comprises a supply pipeline and a return pipeline, the thermosiphon is connected with the liquid supply end of the refrigerating unit (2) through the supply pipeline, and the refrigerating unit (2) conveys working fluid to the thermosiphon through the supply pipeline. The thermosiphon is connected with the working fluid recovery end of the refrigerating unit (2) through a return pipeline, and the industrial liquid in the thermosiphon returns to the refrigerating unit (2) through the return pipeline.
The control system (4) controls the operation of the refrigerating unit (2). Through the control of the control system (4), the whole freezing barrier generation system can realize an active circulation working mode and a passive circulation working mode.
The active circulation working mode is started when the external temperature is higher, namely the refrigerating unit (2) is started, so that the working fluid is moved downwards due to gravity after being cooled, and the temperature of the lower part of the thermosiphon is reduced. The temperature of the soil at the lower part of the thermosiphon is relatively high, and the heat of the soil enables the working fluid at the lower part in the thermosiphon to partially evaporate and move upwards, and then the working fluid is cooled and moved downwards to form the circulation of the working fluid.
In winter or under the condition that the outside air temperature is lower, a passive circulation working mode can be adopted, the refrigerating unit (2) can be closed, and circulation is formed by utilizing the outside cold air and the relatively higher temperature in the soil. In some cases, for example, in the case of large diurnal temperature differences, simultaneous active and passive action may also be used.
As shown in fig. 1, the thermosiphon is a straight thermosiphon (1). The linear thermosiphon (1) is vertically inserted on the ground around the ore deposit (5), and all thermosiphons are annularly arranged around the ore deposit (5). During operation, the thermosiphon freezes the layer of soil around the deposit (5) forming a freezing barrier (6). The upper end of the freezing barrier (6) penetrates through the waterproof top plate (10), and the lower end of the freezing barrier (6) extends into a waterproof bottom plate (11) formed by claystone; the ore deposit (5) is positioned in an area surrounded by the waterproof bottom plate (11), the waterproof top plate (10) and the freezing barrier (6).
In this embodiment, a specific process of the method for preventing and controlling groundwater pollution in the ionic rare earth mining process includes the following steps:
s1) adopting a plurality of geological exploration means to find out the geological characteristics of the mining area and find out the stratum structure and the underground water distribution of the mining area. The location and shape of the required freezing barrier is then determined according to the deposit (5) and the panel area. Generally, the upper end of the freezing barrier (6) penetrates through the waterproof top plate (10), and the lower end of the freezing barrier (6) extends into the waterproof bottom plate (11), so that the ore deposit (5) is positioned in an area enclosed by the waterproof bottom plate (11), the waterproof top plate (10) and the freezing barrier (6).
And S2) according to the position and the shape of the freezing barrier, distributing thermosiphons throughout the region of the freezing barrier to be frozen, wherein the two adjacent thermosiphons are arranged at intervals. The design of the thermosiphon, especially the design of the spacing thereof, directly influences the engineering application effect of the thermosiphon. There are three main ways for determining the distribution design parameters of the thermosiphon: firstly, guessing after field observation of actual engineering; secondly, calculating by using an empirical formula of the effective radius of the thermosiphon according to air temperature, air speed, soil property parameters and the like; thirdly, numerical simulation calculation is adopted, the effective heat transfer radius of the common thermosiphon is 1.5 meters, and the maximum influence radius is 2 meters.
The diameter and specification of the thermosiphon can be flexibly selected according to the specification in advance, and the bending angle, the length and the arrangement mode of the length of the evaporation area at the lower part of the thermosiphon can be flexibly selected according to the specification under different geological conditions. If the bedrock fracture zone and underground water around the ore deposit (5) are distributed more, the angles of the vertical shaft and the directional pore canal are flexibly set by means of directional drilling and the like according to the characteristic that the thermosiphon can be flexibly arranged, so that the continuous integrity of the freezing barrier is ensured, and the anti-seepage performance of the freezing barrier is effective and reliable.
S3) injecting a working fluid medium into the thermosiphon; the matrix surrounding the deposit is frozen by the thermosiphon and forms a frozen earth type freezing barrier.
The thermosiphon, also called coreless gravity type heat pipe or heat rod, is a high-efficiency heat conducting device with unique heat conducting performance. The thermosiphon includes a pipe shell and a working fluid in the pipe shell, the pipe shell is made of a closed metal pipe, and the interior of the pipe shell is pumped into a vacuum state, and the working fluid is a specially-treated low-temperature liquid.
As shown in figure 3, the position A is a heat dissipation section of the thermosiphon, and the position B is an evaporation section of the thermosiphon embedded in the soil body. After the thermosiphon is buried underground, when the temperature of the heat-radiating section of the upper section of the thermosiphon is lower than that of the evaporation section of the lower section of the thermosiphon buried in the soil body, the thermosiphon is started. After the heat is transferred to the working fluid at the hot side through the wall of the thermosiphon tube, the working fluid absorbs the latent heat of vaporization and is evaporated into vapor. Under the action of pressure difference, the vapor evaporated by the working fluid rises to the heat release side in the cavity of the tube shell along the direction shown by the arrow C and contacts with the relatively cold tube wall of the heat release side, latent heat of vaporization is released through the tube wall, and meanwhile, the gaseous working medium is condensed into liquid. The working fluid returns to the heated side along the tube wall in the direction indicated by arrow D within the cavity of the tube shell under the influence of gravity, and absorbs the heat for evaporation. The circulation continuously transfers the underground heat to the ambient air, thereby forming a freezing barrier.
When the temperature of the heat dissipation section of the thermosiphon is higher than that of the evaporation section, steam formed after the working fluid in the thermosiphon is evaporated reaches the condensation side and cannot be condensed, the liquid stops evaporating, and the thermosiphon stops working. Therefore, the heat in the atmosphere can not be transferred to the frozen soil through the thermosiphon, and the process is an active circulation process. If the upper radiating section of the thermosiphon is connected with the active refrigeration equipment, the working fluid can be continuously condensed under the condition that the temperature of the radiating section is overhigh, so that the integrity of the lower freezing barrier is ensured.
S4) monitoring the temperature of the thermosiphon and the surrounding matrix thereof, and keeping the integrity of the frozen soil type freezing barrier.
In step S2), a plurality of drilling positions are selected in the area of the freezing barrier to be frozen, and a vertical shaft for placing the linear thermosiphon (1) is drilled at the drilling positions.
The drilling depth of the vertical shaft is 10-20 cm greater than the length of the linear thermosiphon (1) to be embedded; the diameter of the formed hole of the vertical shaft is more than or equal to 1.5 times of the diameter of the linear thermosiphon (1). The heat dissipation section of the linear thermosiphon (1) is higher than the opening at the end part of the vertical shaft, and the gap between the linear thermosiphon (1) and the vertical shaft is filled with fine sand.
When fine sandy soil is used for filling, the fine sandy soil needs to be filled section by section in a layering mode, the layering is thoroughly poured by water, the phenomena of gaps or incompact and the like are prevented, and the thermosiphon is subjected to improper impact oscillation during installation.
The linear thermosiphon (1) is connected with a refrigerating unit (2) and a circulating pipeline (3), the linear thermosiphon (1) is connected with the refrigerating unit (2) through the circulating pipeline (3), and the refrigerating unit (2) circulates working fluid in the linear thermosiphon (1) through the circulating pipeline (3).
The refrigerating unit (2) can adopt a plurality of groups of refrigerating units, each group of refrigerating units can adopt two 30 horsepower refrigerating machines, and working fluid used by the refrigerating machines comprises ammonia, freon, carbon silicon dioxide, propane and the like. The refrigeration group can ensure that the 25 thermosiphons can work normally under the condition that the external temperature is high and the active circulation needs to be started.
The control end of the refrigerating unit (2) is connected with a control system (4), and the control system (4) controls the refrigerating unit (2) to carry out active circulation and passive circulation.
A plurality of water quality monitoring wells (8) are arranged on the periphery of the freezing barrier area, and all the water quality monitoring wells (8) are arranged around the freezing barrier (6). In the process of rare earth exploitation, the concentration of the leaching agent in the water quality monitoring well (8) is monitored.
In order to monitor the condition of the freezing barrier, in the embodiment, temperature sensors (7) can be arranged at various positions of the thermosiphon according to the shape and the position of the freezing barrier, and the temperature sensors (7) are connected with a control system (4). The temperature sensor (7) detects the temperature, ensures that the temperature in the range of the freezing barrier is lower than the freezing point, and can form the freezing barrier.
The method used in the application cannot cause irreversible change to the surrounding environment, only utilizes the temperature to freeze the soil and water around the deposit (5) to form the freezing barrier, directly removes the thermosiphon and the active refrigeration equipment after the use to melt the freezing barrier, and has small permanent influence on the environment around the deposit.
In terms of energy consumption, according to the existing engineering example, when the local air temperature is low enough to push the thermosiphon to perform passive circulation, the cost is low, no other operation cost is needed except for monitoring the integrity of the freezing barrier, when the air temperature is high, the active refrigeration equipment needs to be started, the required electricity fee is determined according to the local situation, the thickness loss of the freezing barrier is about 2 percent within 7-8 days of power failure, the service life is long, and the service life is 20-50 years.
The position of freezing the barrier can be arranged in a flexible way, not only can cover the whole mining area, but also can be arranged at a fixed point, and the barrier is repairable, even if the barrier is damaged, the repair is simpler, and the operability is strong.
It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art should understand that they can make various changes, modifications, additions and substitutions within the spirit and scope of the present invention.
Claims (8)
1. An ion type rare earth mining process groundwater pollution prevention and control method is characterized in that: the method comprises the following steps:
s1) surveying geological conditions and deposit distribution of a rare earth mining area, and determining the position and the shape of a freezing barrier;
s2) according to the position and the shape of the freezing barrier, thermosiphons are distributed in the region of the freezing barrier needing to be frozen, and the two adjacent thermosiphons are arranged at intervals;
s3) injecting a working fluid medium into the thermosiphon; freezing the matrix around the deposit by a thermosiphon and forming a frozen earth type freezing barrier;
s4) monitoring the temperature of the thermosiphon and the surrounding matrix thereof, and keeping the integrity of the frozen soil type freezing barrier.
2. The method for preventing and controlling the pollution of the groundwater in the ionic rare earth mining process according to claim 1, wherein the method comprises the following steps: the freezing barrier is annularly arranged around the ore deposit, a waterproof bottom plate formed by claystone is arranged below the ore deposit, a waterproof top plate formed by claystone is arranged above the ore deposit, the upper end of the freezing barrier penetrates through the waterproof top plate, and the lower end of the freezing barrier extends into the waterproof bottom plate formed by claystone; the ore deposit is located in the area enclosed by the waterproof bottom plate, the waterproof top plate and the freezing barrier.
3. The method for preventing and controlling the pollution of the groundwater in the ionic rare earth mining process according to claim 2, wherein the method comprises the following steps: the thermosiphon is a linear thermosiphon; in the step S2), a plurality of drilling positions are selected in a freezing barrier area needing freezing, a vertical shaft used for placing a linear thermosiphon is drilled at the drilling positions, a water-proof top plate formed by clay rock above the ore deposit penetrates through the vertical shaft, and a water-proof bottom plate formed by clay rock below the ore deposit is inserted into the lower end of the vertical shaft.
4. The method for preventing and controlling the pollution of the groundwater in the ionic rare earth mining process according to claim 3, wherein the method comprises the following steps: the drilling depth of the vertical shaft is 10-20 cm greater than the length of the linear thermosiphon to be embedded; the diameter of the formed hole of the vertical shaft is more than or equal to 1.5 times of the diameter of the linear thermosiphon; the heat dissipation section at the upper part of the linear thermosiphon is higher than the opening at the end part of the vertical shaft, and the gap between the linear thermosiphon and the vertical shaft is filled with fine sand.
5. The method for preventing and controlling the pollution of the groundwater in the ionic rare earth mining process according to claim 1, wherein the method comprises the following steps: working fluid is filled in the thermosiphon; the thermosiphon is connected with a refrigerating unit and a circulating pipeline, the thermosiphon is connected with the refrigerating unit through the circulating pipeline, and the refrigerating unit circulates working fluid in the thermosiphon through the circulating pipeline; the working fluid includes ammonia, freon, carbon silica, propane, and the like.
6. The method for preventing and controlling the pollution of the groundwater in the ionic rare earth mining process according to claim 5, wherein the method comprises the following steps: the control end of the refrigerating unit is connected with a control system, and the control system controls the refrigerating unit to carry out active circulation and passive circulation;
when the control system controls the refrigerating unit to carry out active circulation, the control system opens an active refrigerating device of the refrigerating unit, and the active refrigerating device circulates the working fluid in the thermosiphon pipe;
when the control system controls the refrigerating unit to carry out active circulation, the control system closes the active refrigerating equipment of the refrigerating unit and utilizes the relatively high temperature of the external cold air and the soil to circulate the working fluid.
7. The method for preventing and controlling the pollution of the groundwater in the ionic rare earth mining process according to claim 1, wherein the method comprises the following steps: arranging a plurality of water quality monitoring wells at the periphery of the freezing barrier area; in the process of rare earth mining, the concentration of a leaching agent in water quality in a water quality monitoring well is monitored.
8. The method for preventing and controlling the pollution of the groundwater in the ionic rare earth mining process according to claim 1, wherein the method comprises the following steps: in the step S2), temperature sensors are arranged at various positions of the thermosiphon according to the shape and the position of the freezing barrier, and the temperature sensors are connected with a control system; the temperature sensor monitors whether the temperature of each part of the thermosiphon is below the freezing point.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4974425A (en) * | 1988-12-08 | 1990-12-04 | Concept Rkk, Limited | Closed cryogenic barrier for containment of hazardous material migration in the earth |
| US5327734A (en) * | 1992-05-15 | 1994-07-12 | The United States Of America As Represented By The Secretary Of The Army | Passive-active thermosyphon |
| US5339893A (en) * | 1992-05-08 | 1994-08-23 | The United States Of America As Represented By The Secretary Of The Army | Apparatus for containing toxic spills employing hybrid thermosyphons |
| US5681130A (en) * | 1996-02-20 | 1997-10-28 | Regents Of The University Of California | Active cooling-based surface confinement system for thermal soil treatment |
| US5730550A (en) * | 1995-08-15 | 1998-03-24 | Board Of Trustees Operating Michigan State University | Method for placement of a permeable remediation zone in situ |
| US20040120772A1 (en) * | 2001-10-24 | 2004-06-24 | Vinegar Harold J. | Isolation of soil with a low temperature barrier prior to conductive thermal treatment of the soil |
| RU2593286C1 (en) * | 2015-07-08 | 2016-08-10 | Общество с ограниченной ответственностью Научно-производственное объединение "Фундаментстройаркос" | Thermal siphon |
| CN106216381A (en) * | 2016-08-05 | 2016-12-14 | 上海漕河泾桃浦科技智慧城经济发展有限公司 | Freezing isolation and in-situ heat desorbing integral system and the processing method of contaminated soil |
| RU198334U1 (en) * | 2019-12-04 | 2020-07-02 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Новосибирский государственный архитектурно-строительный университет (Сибстрин)" | Thermosiphon |
-
2022
- 2022-09-05 CN CN202211079755.6A patent/CN115404915A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4974425A (en) * | 1988-12-08 | 1990-12-04 | Concept Rkk, Limited | Closed cryogenic barrier for containment of hazardous material migration in the earth |
| US5339893A (en) * | 1992-05-08 | 1994-08-23 | The United States Of America As Represented By The Secretary Of The Army | Apparatus for containing toxic spills employing hybrid thermosyphons |
| US5327734A (en) * | 1992-05-15 | 1994-07-12 | The United States Of America As Represented By The Secretary Of The Army | Passive-active thermosyphon |
| US5730550A (en) * | 1995-08-15 | 1998-03-24 | Board Of Trustees Operating Michigan State University | Method for placement of a permeable remediation zone in situ |
| US5681130A (en) * | 1996-02-20 | 1997-10-28 | Regents Of The University Of California | Active cooling-based surface confinement system for thermal soil treatment |
| US20040120772A1 (en) * | 2001-10-24 | 2004-06-24 | Vinegar Harold J. | Isolation of soil with a low temperature barrier prior to conductive thermal treatment of the soil |
| RU2593286C1 (en) * | 2015-07-08 | 2016-08-10 | Общество с ограниченной ответственностью Научно-производственное объединение "Фундаментстройаркос" | Thermal siphon |
| CN106216381A (en) * | 2016-08-05 | 2016-12-14 | 上海漕河泾桃浦科技智慧城经济发展有限公司 | Freezing isolation and in-situ heat desorbing integral system and the processing method of contaminated soil |
| RU198334U1 (en) * | 2019-12-04 | 2020-07-02 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Новосибирский государственный архитектурно-строительный университет (Сибстрин)" | Thermosiphon |
Non-Patent Citations (2)
| Title |
|---|
| 吕昕;吉植强;余竟;于荣;劳丽燕;姚桦;: "人工冻土隔离污染物的应用及展望", 低温建筑技术, no. 06, pages 87 - 89 * |
| 曹代勇；魏迎春: "煤炭地质勘查与评价（第二版）", 31 December 2021, 中国矿业大学出版社有限责任公司, pages: 276 * |
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