Closed coal mine multi-environment field coupling water-rock interaction experiment device and method

Abstract

The invention discloses a water-rock interaction experiment device and method under coupling of closed coal mine multi-environment fields. The device comprises a reagent supply unit, an environment regulation and control unit, a reaction unit and a circulation unit, and coupling simulation of a hydrochemical field, a hydrodynamic field, an oxidation reduction field, a temperature field, a microbial field and a pressure field is realized through cooperative operation. The reagent supply unit provides reaction liquid with a preset pH value, ion concentration or microbial bacterial liquid; the environment regulation and control unit regulates the temperature and the oxidation-reduction state; the reaction unit forms a hydrodynamic field and a pressure field through a fluid control device and a pressure applying device; the circulation unit simulates the pollution accumulation effect. The method comprises the steps of preparing a reaction solution, regulating and controlling the environment, performing water-rock interaction, circulating the reaction solution and analyzing the characteristics of pollutants. The system can truly simulate the closed coal mine water-rock action environment, is suitable for various ores and clear pollutant types, provides data support for targeted treatment, and has high integration, authenticity and wide applicability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geotechnical engineering, mine environment and hydrogeochemistry, and particularly relates to an experimental device and method capable of simulating and coupling multiple environmental fields such as a water chemical field, a hydrodynamic field, a redox field, a temperature field, a microbial field and a pressure field in a laboratory environment, and used for researching the water-rock interaction mechanism of surrounding rock and ore in a closed coal mine and the pollutant generation characteristics of groundwater. BACKGROUND

[0002] Coal resources, as an important pillar of China's energy security, have played a key role in promoting the sustained and stable development of the economy. However, with the deepening of the policy of green mine construction, coal mines with overcapacity are gradually closed, and the number of closed coal mines has increased significantly. However, about one-third of the mines are located in water-rich areas, and the problem of groundwater treatment in closed coal mines has been neglected for a long time, leading to serious pollution and waste of groundwater resources. Groundwater pollution in closed coal mine areas not only comes from the leaching of coal gangue open storage, but also from the water-rock interaction between surrounding rock and ore in the mine and groundwater. This interaction is affected by the coupling of multiple environmental fields (such as water chemical field, hydrodynamic field, redox field, temperature field, microbial field and pressure field) in a complex geological environment, resulting in complex pollution components, including acid mine water, high salinity water and toxic water.

[0003] In the prior art, there are some researches and solutions for groundwater pollution in closed coal mines. For example, Chinese patent document (publication number CN108318660A) discloses a coal gangue leaching soaking test device under the action of multiple field coupling. The device uses a leaching solution barrel to hold distilled water, combined with an acid solution barrel, an alkaline solution barrel and a semiconductor refrigerating sheet, to simulate the leaching soaking test of solid fillers in the goaf under the stress field, seepage field, temperature field and acid-base field. The leaching solution collected in the test is used to analyze the dissolution characteristics of heavy metal elements, providing basic data for solving the environmental pollution problem of solid fillers in the goaf. The advantage of the device is that it can preliminarily simulate the coal gangue leaching process under the action of multiple field coupling, but its main limitation is that it only targets the pollution of coal gangue open storage and fails to cover the water-rock interaction between surrounding rock and ore in the mine and the groundwater, and the simulation capability of the hydrodynamic field and the microbial field is limited, making it difficult to fully reflect the complex pollution mechanism of closed coal mines.

[0004] Another Chinese patent document (publication number CN109336241A) discloses a method for treating acid mine water in closed coal mines, which is suitable for the treatment of acid mine water in abandoned mines with inclined shaft mining. The method uses the original roadway and cheap materials such as limestone to treat acid mine water through an artificial wetland treatment system. When the roadway is blocked and affects the treatment effect, the drainage pipe can be opened or a water pump can be used to dredge, and the discharged water is introduced into the artificial wetland for treatment. The method is simple to operate and low in cost, and makes full use of the existing facilities of the closed coal mine. However, it mainly aims at the treatment of acid mine water and cannot solve other types of pollution problems such as high salinity water or water containing toxic substances, and the construction of artificial wetlands needs to be designed according to the specific pollution characteristics. The existing technology lacks systematic analysis of pollution components, resulting in insufficient pertinence of the treatment scheme.

[0005] In addition, existing technology research shows that the sources of groundwater pollution in closed coal mine areas are complex and diverse. The leaching effect of coal gangue open-air stacking is only one of the pollution sources, and the water-rock interaction of surrounding rock and ore in the mine with groundwater is a more important pollution source. This interaction is affected by the coupling of multiple environmental fields such as water chemical field (pH, ion concentration), hydrodynamic field (seepage velocity, flow state), oxidation-reduction field (oxygen content), temperature field (environmental temperature), microbial field (bacterial metabolism), and pressure field (overburden pressure). Differences in ore-forming geological conditions in different regions result in complex mine water pollution components. For example, sulfide ore can produce acid mine water, carbonate ore can cause high salinity water, and some ores can release heavy metals and other toxic substances. Existing experimental devices can usually only simulate a single or a few environmental fields, and it is difficult to achieve comprehensive simulation of multi-field coupling, and lack the ability to flexibly adjust flow field, strata inclination, pressure and other conditions, resulting in weak relevance of experimental results to actual mine environment. In addition, the closed coal mine water pollution has the characteristics of point source dispersion and continuous generation, and the construction of treatment measures such as artificial wetlands needs to be based on the clear types and characteristics of pollutants, while the existing technology lacks obvious data analysis before pollution treatment, which limits the development and implementation of targeted treatment measures.

[0006] Therefore, there is an urgent need for an experimental device and method that can highly integrate water chemical field, hydrodynamic field, oxidation-reduction field, temperature field, microbial field and pressure field in a laboratory environment, flexibly adjust experimental conditions, realistically simulate water-rock interaction environment in closed coal mines, and clearly determine the types and characteristics of pollutants through reaction liquid analysis to provide data support for targeted treatment. SUMMARY

[0007] Therefore, there is an urgent need for an experimental device and method that can highly integrate water chemical field, hydrodynamic field, oxidation-reduction field, temperature field, microbial field and pressure field in a laboratory environment, flexibly adjust experimental conditions, realistically simulate water-rock interaction environment in closed coal mines, and clearly determine the types and characteristics of pollutants through reaction liquid analysis to provide data support for targeted treatment.

[0008] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0009] A closing coal mine multi-environment field coupling water-rock interaction experimental device, comprising:

[0010] A reagent supply unit configured to provide a reaction liquid with a predetermined pH value, ion concentration or microbial bacteria solution to form a water chemical field and a microbial field;

[0011] An environment control unit in fluid communication with the reagent supply unit, configured to adjust the temperature of the reaction liquid to form a temperature field, and adjust the oxidation-reduction state of the reaction liquid by injecting gas to form an oxidation-reduction field;

[0012] A reaction unit in fluid communication with the environment control unit, configured to accommodate ore samples and provide a water-rock interaction reaction environment, the reaction unit comprising a fluid control device to form a hydrodynamic field, and a pressure applying device to form a pressure field;

[0013] A circulation unit in fluid communication with the reaction unit, configured to collect the reacted liquid and circulate it to the environment control unit or the reagent supply unit to simulate the cumulative effect of water pollution;

[0014] Wherein, the experimental device realizes the coupling simulation of water chemical field, hydrodynamic field, oxidation-reduction field, temperature field, microbial field and pressure field in a single system through the cooperative operation of the reagent supply unit, environment control unit, reaction unit and circulation unit, to study the water-rock interaction mechanism and pollutant generation characteristics.

[0015] Further, the reagent supply unit comprises at least one container configured to accommodate a reaction liquid with a predetermined pH value, ion concentration or microbial bacteria solution, and is in communication with the environment control unit through a controllable valve to adjust the supply rate of the reaction liquid.

[0016] Further, the environment control unit comprises a temperature control device configured to adjust the reaction liquid to a predetermined temperature to form a temperature field, and a gas supply device configured to adjust the oxidation-reduction state of the reaction liquid by injecting gas to form an oxidation-reduction field.

[0017] Further, the reaction unit comprises an outer container and an inner reaction container, the inner reaction container is configured to accommodate ore samples, and the outer container is connected with the pressure applying device to apply a predetermined pressure to form a pressure field.

[0018] Further, the fluid control device comprises at least one controllable valve configured to adjust the flow rate and flow state of the reaction liquid to form a three-dimensional hydrodynamic field, supporting fully submerged, semi-submerged or non-submerged contact state.

[0019] Further, the reaction unit is provided with an adjustable base configured to change the inclination angle of the reaction unit to simulate the water-rock interaction under the actual formation inclination condition.

[0020] Further, the circulation unit comprises a collection container configured to collect the reaction liquid flowing out of the reaction unit, and a circulation pump configured to deliver the collected reaction liquid to the environment regulation unit or the reagent supply unit to simulate the dynamic accumulation effect of water pollution.

[0021] Further, the reaction unit or the circulation unit is provided with a reaction liquid collection port configured to collect the reaction liquid for water quality analysis to determine the types and characteristics of pollutants and provide pollution control guidance.

[0022] Further, the reagent supply unit is configured to provide a reaction liquid containing microbial liquid, and the environment regulation unit is configured to adjust the oxygen content and temperature suitable for microbial growth to simulate the influence of microbial field on water-rock interaction.

[0023] Further, the ore sample comprises sulfide, carbonate or silicate ore to realize water-rock interaction research of different types of ore in a multi-field coupling environment.

[0024] Further, the inner reaction container comprises an upper filter assembly and a lower filter assembly configured to fix the ore sample and allow the reaction liquid to pass through to control the contact area of the reaction liquid with the ore sample.

[0025] Further, the inner reaction container comprises an inlet port and an outlet port, the inlet port is provided at the top or side of the inner reaction container, and the outlet port is provided at the bottom of the inner reaction container, the inlet port and the outlet port are respectively communicated with the fluid control device to form a directional flow hydrodynamic field.

[0026] Further, the pressure applying device comprises a mechanical pressure mechanism or a hydraulic pressure mechanism configured to apply uniform or adjustable pressure to the inner reaction container to simulate the pressure field under different overburden pressure conditions.

[0027] Further, the fluid control device comprises a plurality of controllable valves configured to independently adjust the flow rate of the reaction liquid in different directions, and at least one flow meter configured to monitor the flow rate of the reaction liquid to accurately control the three-dimensional hydrodynamic field.

[0028] Further, the gas supply device comprises a gas flow regulator configured to control the rate of injected gas and a gas distributor configured to uniformly distribute the gas into the reaction liquid to form a uniform redox field.

[0029] Further, the reaction unit comprises a pressure monitoring device configured to monitor the pressure value in the inner reaction container in real time to ensure the stability and controllability of the pressure field.

[0030] Further, the reagent supply unit comprises a plurality of independent containers respectively configured to contain reaction liquids with different chemical properties to simulate water-rock interaction under different water chemical field conditions.

[0031] Further, the environmental control unit comprises a temperature monitoring device configured to monitor the temperature of the reaction liquid in real time to ensure accurate control of the temperature field.

[0032] A method for simulating water-rock interaction under the coupling of multiple environmental fields using the experimental device described above, comprising the following steps:

[0033] a) adding reaction liquid with predetermined pH value, ion concentration or microbial liquid to the reagent supply unit to form water chemical field and microbial field;

[0034] b) adjusting the temperature of the reaction liquid through the environmental control unit to form the temperature field, and adjusting the oxidation-reduction state of the reaction liquid by injecting gas to form the oxidation-reduction field;

[0035] c) delivering the adjusted reaction liquid to the reaction unit to allow the reaction liquid to interact with the ore sample under the hydrodynamic field and pressure field;

[0036] d) collecting the reacted liquid through the circulation unit and circulating it to the environmental control unit or the reagent supply unit to simulate the cumulative effect of water pollution;

[0037] e) collecting the reaction liquid and performing water quality analysis to determine the types and characteristics of pollutants produced by water-rock interaction.

[0038] Further, in step c), the flow rate and flow pattern of the reaction liquid are controlled by adjusting the valves of the flow control device to simulate fully submerged, semi-submerged or non-submerged contact conditions.

[0039] Further, in step c), the angle of the base of the reaction unit is adjusted to simulate water-rock interaction under actual formation dip conditions.

[0040] Further, in step e), the water quality analysis determines the pollutant composition of acid mine water, high salinity water or toxic substance-containing water, providing data support for targeted pollution control.

[0041] Further, in step a), microbial liquid-containing reaction liquid is added to the reagent supply unit, and in step b), the oxygen content and temperature suitable for microbial growth are adjusted to simulate the influence of the microbial field on water-rock interaction.

[0042] The beneficial effects of the present application are:

[0043] The closing coal mine multi-environment field coupling water rock interaction experimental device and method in the present application have the following significant beneficial effects compared with the prior art. These effects not only reflect in technical innovation, but also extend to practical application, environmental protection and scientific research field. Through the integrated design of multi-field coupling simulation, the pain points of the research on groundwater pollution in closed coal mines are solved. The following will be described in detail:

[0044] 1. High integration and coupling

[0045] The present application realizes the comprehensive coupling simulation of water chemical field (adjusting pH value, ion concentration and microbial liquid by reagent supply unit), hydrodynamic field (adjusting flow rate and flow state by fluid control device), oxidation-reduction field (injecting gas to control oxygen content by gas supply device), temperature field (precise temperature adjustment by temperature control device), microbial field (introducing bacterial liquid and adjusting suitable growth conditions) and pressure field (simulating overburden pressure by pressure applying device) in a single experimental device. This integrated design avoids the complexity of multiple devices in the prior art, reduces experimental errors and improves simulation efficiency. For example, in the closed coal mine, water rock interaction is often affected by multiple environmental fields at the same time. The existing device can only simulate a few fields (such as temperature field and acid-base field), while the present application can dynamically couple all six fields through the coordinated operation of units (such as the fluid communication between the environmental control unit and the reaction unit), which reveals the pollution formation mechanism in depth. This not only improves the scientificity of the experiment, but also provides researchers with an efficient laboratory tool, saves time and resource cost, and ultimately helps to accelerate the mechanism research of groundwater pollution in closed coal mines, and promotes the progress of geological engineering field.

[0046] 2. High fidelity simulation

[0047] The present application realizes the realistic restoration of the actual mine environment through a series of flexible adjustment mechanisms, such as multiple controllable valves and flow meters in the fluid control device (supporting accurate control of three-dimensional hydrodynamic field), adjustable base (simulating strata dip angle 0-45°), pressure applying device (mechanical or hydraulic mechanism applying 0.1-10MPa pressure) and monitoring device (real-time feedback of pressure monitoring device and temperature monitoring device). In the prior art, the experimental device often ignores the dynamic change of strata dip angle or pressure field, resulting in large deviation between the simulation result and the actual site. For example, the processing method of CN109336241A utilizes the original roadway, but lacks flexibility in laboratory simulation. The high realism of the present application lies in the ability to simulate completely submerged, semi-submerged or non-submerged contact state, as well as directional flow hydrodynamic field, which is close to the complex geological conditions of closed coal mines (such as inclined bedding and high pressure overburden). This realism not only improves the reliability of experimental data, but also provides a more accurate prediction model for mine environment assessment. For example, in the simulation of the formation process of acid mine water, the influence of temperature change on microbial metabolism can be accurately evaluated, thereby providing a scientific basis for preventing groundwater pollution and reducing trial and error costs in actual governance.

[0048] 3. Wide applicability

[0049] The device of the present application is suitable for water-rock interaction research of various types of ores, including sulfide ores (easy to produce acid mine water), carbonate ores (leading to high salinity water) and silicate ores (may release heavy metal toxicants). Through modular design (such as multiple independent containers of reagent supply unit supporting reaction liquid with different chemical properties), it can easily adapt to different regional ore-forming geological conditions. The prior art is often limited to specific materials, such as CN108318660A only for coal gangue, while the present application fixes ore samples through the upper and lower filter assemblies of the inner reaction container and allows reaction liquid to pass through controlled contact area, expanding the application range. This makes the device not only suitable for closed coal mines, but also can be popularized to water-rock interaction research of other mine environments (such as metal or non-metal mines). In addition, the dynamic cumulative effect simulation of the circulation unit further enhances the applicability, can handle long-term pollution superposition scenarios, provides a platform for interdisciplinary research (such as the combination of hydrogeochemistry and mine environmental engineering), and ultimately promotes the realization of green mine construction and sustainable development goals.

[0050] 4. Strong directivity

[0051] The present invention is to clarify the types and characteristics of pollutants (such as pH value, sulfate concentration, heavy metal dissolution) by the reaction liquid collection port set by the reaction unit and the circulation unit, in combination with the water quality analysis step, and provide a strong data guide for the closure of coal mine groundwater pollution control. Although the existing technology such as CN109336241A has a treatment method, it lacks pre-pollution analysis, resulting in strong blindness in the construction of artificial wetlands. The present invention fills this gap. For example, in the experimental method, by collecting the reaction liquid for analysis, the specific components of acid mine water (pH reduction, sulfate increase), high mineralization water (total dissolved solids increase) or toxic water (heavy metal excess) can be determined, providing support for targeted measures (such as selective adsorption materials or bioremediation). This not only reduces the cost of treatment, but also improves efficiency. For example, in the application example, the simulation results directly guide the design of the artificial wetland program, avoiding waste of resources. At the same time, this guidance helps policy formulation, such as providing environmental assessment data for coal mine closures and promoting the improvement of environmental protection laws and regulations.

[0052] In summary, the beneficial effects of the present invention have formed a closed-loop advantage through technology integration, real simulation, wide application and governance orientation, which is significantly better than existing technologies, can effectively solve the challenges of closed coal mine groundwater pollution, and has broad promotion value.

[0053] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0055] Figure 1 This is a structural schematic diagram of the water-rock interaction experimental device for closed coal mine multi-environmental field coupling according to the present invention.

[0056] Figure numerals: 1-reagent barrel; 2-valve; 3-pipeline; 4-refrigerable constant temperature box; 5-oxygen pump; 6-pipeline; 7-valve; 8-pipeline; 9-liquid inlet pipeline; 10-valve; 11-pipeline; 12-liquid inlet pipe; 13-press; 14-liquid inlet pressure plate; 15-filter plate; 16-filter plate; 17-leakage pressure plate; 18-inner reaction barrel; 19-outer supporting barrel; 20-reaction liquid collecting hole; 21-reaction liquid container; 22-liquid outlet pipeline; 23-pipeline; 24-telescopic base; 25-circulating liquid adding barrel; 26-water lifting pipeline; 27-water lifting pump; 28-circulating liquid inlet pipeline; 29-pipeline. DETAILED DESCRIPTION

[0057] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0058] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the dimensions of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.

[0059] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "back", etc. indicating directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0060] Example 1

[0061] like Figure 1 As shown, the water-rock interaction experimental device for the multi-environmental field coupling of a closed coal mine of the present invention includes a reagent barrel 1, a refrigerated constant temperature box 4, an oxygen pump 5, an inner reaction barrel 18, an outer supporting barrel 19, a circulating liquid adding barrel 25 and other components. The components are connected by pipelines and valves to form a height difference to utilize gravity to drive the reaction liquid to flow.

[0062] Reagent Tank 1: Located at the highest point of the device, it holds the prepared reaction solution, including solutions with a predetermined pH value, ion concentration, or microbial culture, to form the water chemical and microbial fields. Reagent Tank 1 is connected to a refrigerated constant temperature chamber 4 via a pipeline 3. A valve 2 is located at the bottom to control the supply rate of the reaction solution, ensuring that the reaction solution flows into the refrigerated constant temperature chamber 4 by gravity. Reagent Tank 1 can include multiple independent containers, each containing a reaction solution with different chemical properties (such as an acidic solution, a neutral solution, or a culture of sulfate-containing bacteria).

[0063] Refrigerated incubator 4: located below reagent barrel 1 and above inner reaction barrel 18, height can be adjusted by support to optimize gravity-driven hydrodynamic conditions. Refrigerated incubator 4 is used to adjust the temperature of the reaction liquid (5-60℃), forming a temperature field; through the oxygen pump 5 to inject oxygen or other gas, to regulate the redox state of the reaction liquid, forming a redox field, and provide suitable oxygen conditions for microbial field. Refrigerated incubator 4 is connected to oxygen pump 5 through pipeline 6, and is connected to inner reaction barrel 18 through pipeline 8, liquid inlet pipeline 9, pipeline 11, valve 7 and valve 10. Valve 7 and valve 10 are used to adjust the flow rate and flow pattern of the reaction liquid, supporting the formation of hydrodynamic field.

[0064] Oxygen pump 5: connected to refrigerated incubator 4 through pipeline 6, controls the oxygen pumping rate (such as 0.1-2L / min), provides oxygen conditions for redox field and microbial field. Oxygen pump 5 can be equipped with gas flow regulator and gas distributor inside to ensure uniform distribution of gas.

[0065] Water-rock reaction barrel: composed of outer containment barrel 19 and inner reaction barrel 18, located below refrigerated incubator 4. Inner reaction barrel 18 is used to contain ore samples (such as sulfide, carbonate or silicate ore) and provide a reaction site for water-rock interaction. Filter plate 15 (upper part) and filter plate 16 (lower part) are set inside inner reaction barrel 18 to fix ore samples and allow reaction liquid to pass through, controlling the contact area. Liquid inlet pressure plate 14 is located at the top and connected to liquid inlet pipe 12, used to distribute reaction liquid uniformly. Liquid leakage pressure plate 17 is located at the bottom to collect leaked reaction liquid. Liquid inlet pipe 12 is connected to refrigerated incubator 4 through pipeline 11 and valve 10. Reaction liquid flows in from the top and side, forming a three-dimensional hydrodynamic field, supporting fully submerged, semi-submerged or non-submerged state. Outer containment barrel 19 is connected to pressure machine 13 to apply a predetermined pressure (such as 0.1-10MPa), forming a pressure field to simulate overburden pressure conditions. Telescopic base 24 is located below outer containment barrel 19, adjusting the height difference through telescopic mechanism at different positions to change the inclination angle of inner reaction barrel 18 (0-45°), simulating the actual formation dip angle. Reaction liquid collection hole 20 is set at the bottom of outer containment barrel 19 to collect the liquid after reaction, flowing into reaction liquid container 21 for water quality analysis.

[0066] Circulating liquid addition barrel 25: located at the lowest position of the device, connected to inner reaction barrel 18 through liquid outlet pipeline 22 and pipeline 23, used to collect reaction liquid to simulate the dynamic cumulative effect of water pollution. Water lifting pipeline 26, water lifting pump 27, circulating liquid inlet pipeline 28 and pipeline 29 transport reaction liquid back to refrigerated incubator 4, realizing the cycle of liquid addition-reaction-liquid addition. Reaction liquid container 21 assists in storing reaction liquid flowing out of reaction liquid collection hole 20, facilitating subsequent analysis.

[0067] The device realizes the coupling simulation of water chemical field, water power field, oxidation-reduction field, temperature field, microbial field and pressure field in a single system through the coordinated operation of the reagent barrel 1, the refrigeratable thermostat 4, the inner reaction barrel 18, the outer containing barrel 19 and the circulating liquid adding barrel 25, and utilizes gravity driving and valve control.

[0068] Example 2:

[0069] The method for carrying out water rock interaction experiment under multi-environment field coupling using the device in Example 1 comprises the following steps:

[0070] 1. Device assembly

[0071] Before the experiment starts, all valves (valve 2, valve 7 and valve 10) are kept closed to prevent the reaction liquid from flowing accidentally. The filter plate 16 (lower part) and the liquid leakage pressure plate 17 are installed at the bottom of the inner reaction barrel 18, the experimental ore (such as sulfide ore) is added, and then the filter plate 15 (upper part) and the liquid inlet pressure plate 14 are installed to fix the ore sample. The liquid inlet pipe 12 is connected to the top of the inner reaction barrel 18, the liquid inlet pipeline 9 is connected to the side of the inner reaction barrel 18, and the refrigeratable thermostat 4 is communicated through the pipeline 8, the pipeline 11 and the valve 10. The pressure machine 13 is assembled to the outer containing barrel 19, and the pressure is adjusted to the target value (such as 2 MPa). The height difference at different positions is adjusted by the telescopic base 24 (such as one side is 10 cm higher and the other side is 5 cm lower), so that the inner reaction barrel 18 is inclined to the target angle (such as 30°) to simulate the dip angle condition of the stratum. The reagent barrel 1 and the refrigeratable thermostat 4 are connected (through the pipeline 3 and the valve 2), the pump oxygen machine 5 and the refrigeratable thermostat 4 are connected (through the pipeline 6), the inner reaction barrel 18 and the circulating liquid adding barrel 25 are connected (through the liquid outlet pipeline 22 and the pipeline 23), and the water lifting pump 27 is connected back to the refrigeratable thermostat 4 (through the water lifting pipeline 26, the circulating liquid inlet pipeline 28 and the pipeline 29) to ensure fluid communication.

[0072] 2. Reagent configuration and supply

[0073] The prepared reaction liquid is added to the reagent barrel 1, including acidic solution (pH 4), sulfate-containing solution (500 mg / L) and bacteria solution containing sulfuric acid bacteria, to form the water chemical field and the microbial field. The valve 2 is opened, and the reaction liquid flows into the refrigeratable thermostat 4 through the pipeline 3 by gravity, and the valve 2 adjusts the supply rate (such as 0.1-1 mL / s).

[0074] 3. Environmental regulation

[0075] Adjust the height of the refrigerated incubator 4 (e.g. 20 cm lower than the reagent barrel 1, 15 cm higher than the inner reaction barrel 18) to optimize the gravity-driven flow. Set the temperature of the refrigerated incubator 4 to the target value (e.g. 25℃) to form the temperature field. Turn on the pump oxygen machine 5 to inject oxygen (flow rate 0.5 L / min) through the pipeline 6 to form the redox field and provide suitable oxygen conditions for the microbial field.

[0076] 4. Water-rock interaction reaction

[0077] Turn on the valve 7 and the valve 10 to make the reaction liquid flow into the inner reaction barrel 18 through the pipeline 8, the liquid inlet pipeline 9, the pipeline 11, and the liquid inlet pipeline 12 to contact with the ore sample. Adjust the valve 7 and the valve 10 to control the flow rate (e.g. 0.5 mL / s) and the flow state, so that the water level of the reaction liquid reaches the preset height (e.g. half-submerged state, covering 50% of the ore sample), to form the three-dimensional hydrodynamic field. The press machine 13 applies pressure (e.g. 2 MPa) to form the pressure field. The telescopic base 24 maintains an inclination of 30° to simulate the stratum conditions. The reaction liquid penetrates the ore sample through the filter plate 15, the filter plate 16, and the liquid leakage pressure plate 17.

[0078] 5. Circulation and collection

[0079] The reaction liquid flows into the circulating liquid addition barrel 25 through the liquid outlet pipeline 22 and the pipeline 23. When the water level of the circulating liquid addition barrel 25 reaches the preset height (e.g. 80% of the barrel capacity), open the circulating liquid inlet pipeline 28 switch to start the water lifting pump 27 to transport the reaction liquid back to the refrigerated incubator 4 through the water lifting pipeline 26 and the pipeline 29, forming a cycle of liquid addition-reaction-liquid addition. Open the valve on the reaction liquid collection hole 20 periodically to collect the reaction liquid into the reaction liquid container 21 for water quality analysis.

[0080] 6. Water quality analysis

[0081] Analyze the reaction liquid in the reaction liquid container 21 to determine the types and characteristics of pollutants (e.g. pH value and sulfate concentration of acid mine water, total dissolved solids of high salinity water, heavy metal concentration of toxic water), providing data support for targeted pollution control.

[0082] Example 3

[0083] Sulfide ore experiment: The device in Example 1 is used for water-rock interaction research of sulfide ore in a certain closed coal mine. Acidic reaction solution (pH 3.5) and bacteria solution containing sulfur-oxidizing bacteria are added to reagent barrel 1, the temperature of refrigerated incubator 4 is set to 30°C, pump oxygen machine 5 oxygen flow rate is 1 L / min, valve 7 and valve 10 control flow rate 0.5 mL / s, press 13 applies 5 MPa, telescopic base 24 is adjusted to 20° inclination. The reaction solution enters the inner reaction barrel 18 through the liquid inlet pipeline 9 and the liquid inlet pipe 12, and is in semi-submerged contact with the ore sample, penetrates through the filter plate 15, the filter plate 16 and the liquid leakage pressure plate 17, and is discharged to the circulating liquid addition barrel 25 through the liquid outlet pipeline 22. The water pump 27 circulates the delivery. Through the reaction liquid collection hole 20 and the reaction liquid container 21, the results show that the concentration of sulfate ions increases to 800 mg / L, and the dissolution amount of heavy metals (such as Fe, Zn) is significantly increased, which provides key data for the treatment scheme of constructed wetlands.

[0084] Carbonate ore experiment: In order to demonstrate the wide applicability of the device, further experiments on carbonate ore are carried out. Neutral solution (pH 7) and sulfate solution (1000 mg / L) containing sulfuric acid are added to reagent barrel 1, the temperature of refrigerated incubator 4 is set to 20°C, pump oxygen machine 5 oxygen flow rate is 0.3 L / min, valve 7 and valve 10 control flow rate 0.3 mL / s, press 13 applies 3 MPa, telescopic base 24 is adjusted to 15° inclination. The reaction solution enters the inner reaction barrel 18 through the liquid inlet pipeline 9, and is in complete submerged contact with the ore sample, and is discharged to the circulating liquid addition barrel 25 through the liquid outlet pipeline 22. The analysis results show that the total dissolved solids increase significantly, indicating the characteristics of high salinity water, which provides the basis for optimizing the neutralization treatment process.

[0085] Finally, it should be pointed out that the above examples are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, which should be covered by the scope of the claims of the present application.

Claims

1. A water-rock interaction experimental device for closed coal mine multi-environmental field coupling, characterized by: include: a reagent supply unit configured to provide a reaction solution having a predetermined pH value, ion concentration or microbial liquid to form a water chemical field and a microbial field; an environmental control unit, in fluid communication with the reagent supply unit, configured to adjust the temperature of the reaction liquid to form a temperature field, and to adjust the redox state of the reaction liquid by injecting gas to form a redox field; a reaction unit, in fluid communication with the environment control unit, configured to accommodate an ore sample and provide a reaction environment for water-rock interaction, the reaction unit comprising a fluid control device for forming a hydrodynamic field, and a pressure applying device for forming a pressure field; a circulation unit, in fluid communication with the reaction unit, configured to collect the reacted liquid and circulate it to the environment control unit or the reagent supply unit to simulate the cumulative effect of water pollution; Among them, the experimental device realizes the coupled simulation of water chemical field, water dynamic field, redox field, temperature field, microbial field and pressure field in a single system through the coordinated operation of the reagent supply unit, environmental control unit, reaction unit and circulation unit, so as to study the water-rock interaction mechanism and pollutant generation characteristics.

2. The experimental device according to claim 1, characterized in that The reagent supply unit includes at least one container configured to contain a reaction solution with a predetermined pH value, ion concentration or microbial liquid, and is connected to the environment control unit through a controllable valve to adjust the supply rate of the reaction solution.

3. The experimental device according to claim 1, characterized in that The environmental control unit includes a temperature control device and a gas supply device. The temperature control device is configured to adjust the reaction liquid to a predetermined temperature to form a temperature field. The gas supply device is configured to adjust the redox state of the reaction liquid by injecting gas to form a redox field.

4. The experimental device according to claim 1, characterized in that The reaction unit includes an outer holding container and an inner reaction container, the inner reaction container is configured to contain the ore sample, and the outer holding container is connected to the pressure applying device to apply a predetermined pressure to form a pressure field.

5. The experimental device according to claim 1, characterized in that: The fluid control device includes at least one controllable valve configured to adjust the flow rate and flow state of the reaction liquid to form a three-dimensional hydrodynamic field and support a fully submerged, semi-submerged or non-submerged contact state.

6. The experimental device according to claim 1, characterized in that The reaction unit is provided with an adjustable base, which is configured to change the inclination angle of the reaction unit to simulate the water-rock interaction under actual formation inclination conditions.

7. The experimental device according to claim 1, characterized in that The circulation unit includes a collection container and a circulation pump. The collection container is configured to collect the reaction liquid flowing out of the reaction unit, and the circulation pump is configured to transport the collected reaction liquid to the environmental control unit or the reagent supply unit to simulate the dynamic cumulative effect of water pollution.

8. The experimental device according to claim 1, characterized in that: The reaction unit or circulation unit is provided with a reaction liquid collection port, which is configured to collect the reaction liquid for water quality analysis. The water quality analysis is used to determine the types and characteristics of pollutants to provide guidance for pollution control.

9. The experimental device according to claim 1, characterized in that: The reagent supply unit is configured to provide a reaction liquid containing microbial liquid, and the environment control unit is configured to adjust the oxygen content and temperature suitable for the growth of microorganisms to simulate the influence of the microbial field on the water-rock interaction.

10. The experimental device according to claim 1, characterized in that: The ore samples include sulfide, carbonate or silicate ores, and the water-rock interaction study of different types of ores is realized in a multi-field coupling environment.

11. The experimental device according to claim 4, characterized in that: The inner reaction container includes an upper filter assembly and a lower filter assembly, and the upper filter assembly and the lower filter assembly are configured to fix the ore sample and allow the reaction liquid to pass through, so as to control the contact area between the reaction liquid and the ore sample.

12. The experimental device according to claim 4 or 11, characterized in that: The inner reaction container includes a liquid inlet port and a liquid outlet port, wherein the liquid inlet port is arranged at the top or side of the inner reaction container, and the liquid outlet port is arranged at the bottom of the inner reaction container. The liquid inlet port and the liquid outlet port are respectively connected to the fluid control device to form a hydrodynamic field of directional flow.

13. The experimental device according to claim 4, characterized in that The pressure applying device includes a mechanical pressure mechanism or a hydraulic pressure mechanism, configured to apply uniform or adjustable pressure to the inner reaction vessel to simulate the pressure field under different coating pressure conditions.

14. The experimental device according to claim 5, characterized in that The fluid control device includes multiple controllable valves and at least one flow meter. The multiple controllable valves are configured to independently adjust the flow rate of the reaction liquid in different directions, and the flow meter is configured to monitor the flow rate of the reaction liquid to accurately control the three-dimensional hydrodynamic field.

15. The experimental device according to claim 1, characterized in that The gas supply device includes a gas flow regulator and a gas distributor. The gas flow regulator is configured to control the rate of gas injection, and the gas distributor is configured to uniformly distribute the gas into the reaction liquid to form a uniform redox field.

16. The experimental device according to claim 4, characterized in that The reaction unit includes a pressure monitoring device configured to monitor the pressure value in the inner reaction container in real time to ensure the stability and controllability of the pressure field.

17. The experimental device according to claim 1, characterized in that The reagent supply unit includes a plurality of independent containers, each of which is configured to contain reaction liquids with different chemical properties to simulate water-rock interactions under different water chemical field conditions.

18. The experimental device according to claim 1, characterized in that The environmental control unit includes a temperature monitoring device configured to monitor the temperature of the reaction liquid in real time to ensure accurate control of the temperature field.

19. A method for simulating water-rock interaction under multi-environmental field coupling using the experimental device according to any one of claims 1 to 18, characterized in that: The following steps are involved: a) adding a reaction solution having a predetermined pH value, ion concentration or microbial liquid to a reagent supply unit to form a water chemical field and a microbial field; b) regulating the temperature of the reaction solution by an environmental control unit to form a temperature field, and regulating the redox state of the reaction solution by injecting gas to form a redox field; c) transporting the adjusted reaction liquid to the reaction unit, so that the reaction liquid and the ore sample undergo water-rock interaction under the hydrodynamic field and pressure field; d) collecting the reacted liquid through a circulation unit and circulating it to the environmental control unit or the reagent supply unit to simulate the cumulative effect of water pollution; e) Collect the reaction liquid and conduct water quality analysis to determine the types and characteristics of pollutants produced by water-rock interaction.

20. The method according to claim 19, characterized in that In step c), the flow rate and flow state of the reaction liquid are controlled by adjusting the valve of the fluid control device to simulate a contact state of complete submergence, semi-submergence or non-submergence.

21. The method according to claim 19, wherein In step c), the water-rock interaction under actual formation dip conditions is simulated by adjusting the base angle of the reaction unit.

22. The method according to claim 19, wherein In step e), the pollutant components of acid mine water, highly mineralized water or water containing toxic substances are determined through water quality analysis to provide data support for targeted pollution control.

23. The method according to claim 19, wherein In step a), a reaction solution containing microbial liquid is added to the reagent supply unit, and in step b), the oxygen content and temperature suitable for microbial growth are adjusted to simulate the influence of the microbial field on the water-rock interaction.

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