Deep layer re-injection high mineralization mine water whole cycle control chemical plugging method and system

Abstract

The application provides a deep high-mineralization mine water full-cycle control chemical plugging method and system, and the method comprises the following steps: step one, water sample collection and detection and basic index monitoring of the environment; step two, carrying out simulation test to determine the water quality of the backfill water; step three, screening three kinds of filter materials for removing iron ions and manganese ions in the backfill water, and determining the optimal ratio; step four, determining the main chemical substances of the backfill plugging through indoor test; and step five, selecting an acid agent, calculating the dosage and accurately removing the chemical precipitate; in the application, starting from the full cycle of deep backfill of high-mineralization mine water, after fully revealing three fundamental reasons for causing chemical plugging caused by deep backfill of high-mineralization mine water, the method for controlling the water quality before backfill, pre-treatment of the backfill water and rapid removal of chemical plugging in the backfill is proposed, and the risk of chemical plugging during backfill is maximally controlled.

Description

Technical Field

[0001] This invention belongs to the field of mine water technology, and relates to the deep storage and utilization of mine water, specifically to a method and system for controlling chemical blockage throughout the entire cycle of deep reinjection of high-mineralization mine water. Background Technology

[0002] Western my country is a region rich in coal resources, but also an arid and semi-arid area with scarce water resources. It accounts for 70% of the country's total coal reserves, but only 3% of its water resources. Mine water is a crucial resource for ensuring ecological, production, and domestic water supply in mining areas. However, with the extension of coal mining to deeper layers or lower coal seams, changes in hydrogeological conditions, and the combined effects of high-intensity mining activities and water-rock interactions, the mineralization of mine water has increased, and the total dissolved solids (TDS) concentration exceeds 1000 mg / L (exceeding the Class III limit of 1000 mg / L in both the "Standards for Drinking Water Quality" and the "Standards for Groundwater Quality"). High-mineralized mine water tastes bitter and is not suitable for direct consumption; direct discharge of high-mineralized mine water without treatment will cause soil salinization; direct irrigation with high-mineralized mine water will cause plants to wither and die, damaging the ecological environment. Therefore, the treatment and utilization of high-mineralized mine water in western China is essential.

[0003] High-salinity mine water requires advanced treatment, such as concentration, before comprehensive utilization. However, this advanced treatment faces numerous challenges, including large processing scale, high costs, and difficulties in disposing of the resulting concentrated brine. Reinjecting high-salinity mine water through boreholes to depths of over 1000m and storing it in deep aquifers not only reduces treatment costs but also plays a crucial role in replenishing groundwater resources and promoting deep water circulation. Therefore, deep reinjection offers a new concept and approach for the storage and utilization of high-salinity mine water.

[0004] During the reinjection of high-salinity mine water, chemical blockage is prone to occur due to factors such as the original mine water quality, aquifer rock properties, and the temperature and pressure of deep strata. The causes of chemical blockage include the following three aspects: First, after high-salinity mine water enters deep aquifers, the difference in quality between the high-salinity mine water and the aquifer water leads to new chemical precipitation due to the mixing of the two water qualities. Second, the high-salinity mine water in western regions has high iron and manganese content. During reinjection into deep aquifers, the pH level in the deep aquifers is higher than that of the mine water. Under high pH conditions, iron and manganese mainly react as Fe. 3+ and Mn 2+In its existing form, it generates new ferric hydroxide and manganese hydroxide precipitates through redox reactions, reducing the permeability of rock pores; third, after highly mineralized mine water enters deep aquifers, both temperature and pressure increase, disrupting the original hydrogeochemical balance, reducing the solubility of CO2, and increasing the CO3 content in the aquifer. 2- Increased concentration increases the probability of CaCO3 precipitation. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a method and system for controlling chemical blockage throughout the entire lifecycle of deep reinjection of high-mineralization mine water. This solution addresses the technical problems in existing technologies where chemical blockage is caused by mismatch between the reinjection water quality and the target aquifer water quality, the easy formation of ferric hydroxide and manganese hydroxide precipitates by iron and manganese elements in the reinjection water, and the increased precipitation of calcium and magnesium ions due to the high temperature and pressure environment in deep formations.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A method for controlling chemical blockage throughout the entire lifecycle of deep reinjection of high-salinity mine water, the method comprising the following steps:

[0008] Step 1: Water sample collection and testing, and monitoring of basic environmental indicators:

[0009] The collection and testing of high-salinity mine water samples to be reinjected and water samples from the target aquifer, as well as the monitoring of basic environmental indicators of the target aquifer.

[0010] The basic indicators of the target reinjection aquifer environment include temperature and pH.

[0011] Step 2: Conduct simulation tests to determine the quality of the reinjected water:

[0012] Based on the basic indicators of the target reinjection aquifer environment obtained in step one, a numerical model for the reinjection test of high-salinity mine water is constructed to simulate the test when the high-salinity mine water sample to be reinjected is mixed with the target reinjection aquifer water sample in different proportions.

[0013] Based on the operation of the experimental numerical model, the amount of chemical precipitation under different mixing ratios was quantitatively calculated. Based on the principle of minimizing the amount of chemical precipitation, a linear superposition model of the high-mineralization mine water sample to be reinjected and the target aquifer water sample was constructed to finally determine the water quality of the reinjected water.

[0014] Step 3: Screen three types of filter media for removing iron and manganese ions from the reinjected water and determine the optimal ratio:

[0015] Step 2 has determined the concentrations of iron and manganese ions in the reinjected water. Before reinjection, a filtration test for iron and manganese ions is conducted to initially select three filter media with strong adsorption properties for iron and manganese ions and determine the optimal mixing ratio of the three filter media.

[0016] Step 4: Indoor testing to determine the main chemical substances causing the reinjection blockage:

[0017] First, the iron and manganese ions in the reinjection water are treated using the three types of filter media described in step three to obtain treated reinjection water.

[0018] Secondly, before reinjecting the treated reinjection water, a simulation test of the interaction between the reinjection water and the target rock was conducted indoors. The chemical substances that caused the blockage were then identified in the rock after the simulation test.

[0019] Finally, the treated reinjection water is reinjected.

[0020] Step 5: Select the acid and calculate the dosage to accurately remove the chemical precipitate.

[0021] Based on the chemical substance causing the blockage identified in step four, select the matching acid type, and determine the final amount of acid based on the acid concentration, the length and radius of the reinjection pipe during actual use.

[0022] The present invention also has the following technical features:

[0023] Specifically, in step one, the water samples of the high-mineralization mine water to be reinjected are collected from different locations underground, including the roof water spray point, the drainage borehole, and the central water tank.

[0024] The collection of water samples from the target reinjection aquifer was carried out during drilling.

[0025] The high-salinity mine water samples to be reinjected and the target aquifer water samples, after filtration, were analyzed using inductively coupled ion chromatography (ICC) to detect the K content in both samples. + Na + Ca 2+ Mg 2+ SO4 2- and Cl - The concentration of HCO3 was determined by chemical methods in the high-salinity mine water samples to be reinjected and the target aquifer water samples. - The concentration.

[0026] Preferably, in step two, determining the quality of the reinjected water specifically includes the following steps:

[0027] Step 201: Using the Interactive module in the PHREEQC numerical simulation software, conduct a simulation test with a ratio of (1-9):(1-9) between the proposed high-salinity mine water sample and the target aquifer water sample. For each test, input the average concentration of the proposed high-salinity mine water sample and the concentration of different ions in the target aquifer water sample.

[0028] The average concentration of the different ions is obtained by calculating the average value of the different ion concentrations collected and detected in step one.

[0029] The temperature and pH levels set in the Interactive module are parameters monitored in the target reinjection aquifer environment during step one.

[0030] Step 202: Based on the simulation experiment in step 201, obtain the mixing results of more than 8 groups of high-mineralization mine water samples to be reinjected with the target aquifer water samples in different proportions, that is, obtain the chemical precipitation amount of more than 8 groups of different substances.

[0031] Step 203: Sum the chemical precipitation amounts of each group in Step 202 to obtain the total chemical precipitation amount in each group of experiments. Based on the principle of minimizing chemical precipitation, the mixing ratio of the group of high-mineralization mine water samples to be reinjected with the minimum chemical precipitation amount to the target aquifer water sample is taken as the optimal reinjection ratio.

[0032] The water mixed with the high-salinity mine water sample to be reinjected and the target aquifer water sample under the optimal reinjection ratio is the reinjected water.

[0033] Step 204: Based on the optimal reinjection ratio in Step 203, calculate K in the reinjected water by constructing a linear superposition model. + Na + Ca 2+ Mg 2+ SO4 2- Cl - and HCO3 - The concentrations of the seven ions can be determined using a linear superposition model:

[0034] C 回注 =K1×C 矿井水 +K2×C 地下水

[0035] In the formula:

[0036] C 回注 The concentration of a certain ion in the reinjected water is expressed in mg / L.

[0037] K1 represents the proportion of the high-salinity mine water sample to be reinjected in the optimal reinjection ratio obtained in the mixing test;

[0038] K2 represents the proportion of the target aquifer water sample in the optimal reinjection ratio obtained in the mixing test;

[0039] C 矿井水 To determine the K content in the high-salinity mine water sample to be reinjected + Na + Ca 2+ Mg 2+ SO4 2- Cl - or HCO3 - The average concentration, expressed in mg / L;

[0040] C 地下水 K was injected into the aquifer water sample for the target. + Na + Ca 2+ Mg 2+ SO4 2- Cl - or HCO3 - Concentration, in mg / L.

[0041] Preferably, in step three, the optimal mixing ratio of the three filter materials is coconut shell biochar: black sand: fly ash ceramsite = 80 wt.%: 10 wt.%: 10 wt.%.

[0042] Preferably, in step five, when the chemical substance is calcium carbonate or magnesium carbonate, the acid is dilute hydrochloric acid.

[0043] When the chemical substance is calcium sulfate or magnesium sulfate, the acid is hydrofluoric acid.

[0044] This invention also protects a deep reinjection system for full-cycle control of chemical blockage in high-salinity mine water, which is used to perform the deep reinjection system for full-cycle control of chemical blockage in high-salinity mine water as described above.

[0045] The system includes an intelligent mixing and control device for reinjected water quality, a multi-media stratified filtration tank for iron and manganese, and an acid injection device with precise flow control.

[0046] The aforementioned intelligent mixing control device for reinjected water quality is used to execute step two.

[0047] The iron-manganese multi-media stratified filtration tank is used to perform step three.

[0048] The acid injection device with precise flow control is used to perform step five.

[0049] Specifically, the system also includes a water tank, inside which is a water pump. The water pump is connected to one end of the first water supply pipe, and the other end of the first water supply pipe is connected to the mine water inlet of the intelligent mixing control device for reinjected water quality. The bottom of the intelligent mixing control device for reinjected water quality is also equipped with a mixing tank drain outlet, which is connected to one end of the second water supply pipe, and the other end of the second water supply pipe is connected to the water storage tank.

[0050] The water storage tank is also equipped with a water storage tank outlet, which is connected to the third water supply pipe. The third water supply pipe is equipped with a third water supply pipe branch port, which is connected to one end of the first branch of the third water supply pipe and one end of the second branch of the third water supply pipe, respectively.

[0051] The first water supply pipe is also provided with a first water supply pipe branch port, which is connected to the other end of the first branch of the third water supply pipe.

[0052] The other end of the second branch of the third water supply pipe is connected to the reinjection water inlet in the iron-manganese multi-media stratified filtration tank.

[0053] The iron-manganese multi-media stratified filtration tank is also equipped with a clean water outlet, which is connected to one end of the fourth water supply pipe, and the other end of the fourth water supply pipe is connected to a deep well underground.

[0054] The deep well is also equipped with a second acid injection pipe, which is connected to the acid output port of the acid injection device with precise flow control.

[0055] Specifically, the intelligent mixing control device for reinjected water quality includes a mixing tank, with an outer chamber inside the mixing tank, and a top-open mixing cavity formed by a top-open cylinder inside the outer chamber.

[0056] The inner wall of the mixing chamber is provided with a first mine water inlet pipe and a first groundwater inlet pipe; multiple nozzles are evenly arranged on the first mine water inlet pipe and the first groundwater inlet pipe respectively.

[0057] The top of the first mine water inlet pipe is open, the bottom of the first mine water inlet pipe is connected to the mine water pipe branch port on the second mine water inlet pipe, one end of the second mine water inlet pipe is connected to the mine water inlet on the outside of the bottom of the mixing tank, and the other end of the second mine water inlet pipe is connected to the bottom of the mixing chamber.

[0058] The top of the first groundwater inlet pipe is open, the bottom of the first groundwater inlet pipe is connected to one end of the second groundwater inlet pipe, and the other end of the second groundwater inlet pipe is connected to the groundwater inlet on the outside of the bottom of the mixing tank.

[0059] The second groundwater inlet pipe is also equipped with a groundwater inlet branch, which is connected to the bottom of the mixing chamber.

[0060] The channel formed by the mine water inlet, the second mine water inlet pipe, the mine water pipe branch, the first mine water inlet pipe, and the mixing chamber is a mine water inlet channel; the channel formed by the mine water inlet, the second mine water inlet pipe, and the mixing chamber is also a mine water inlet channel.

[0061] The passage formed by the groundwater inlet, the second groundwater inlet pipe, the first groundwater inlet pipe, and the mixing chamber is a groundwater inlet channel; the passage formed by the groundwater inlet, the second groundwater inlet pipe, the branch of the groundwater inlet pipe, and the mixing chamber is also a groundwater inlet channel.

[0062] The bottom of the mixing tank is also provided with a mixing tank drain outlet. A first gap is provided between the top of the outer compartment and the top of the mixing chamber. A second gap is provided between the inner side wall of the mixing tank and the outer side wall of the mixing chamber. The channel formed by the first gap, the second gap and the mixing tank drain outlet is a drainage channel.

[0063] Specifically, the iron-manganese multi-media stratified filtration tank includes a horizontally arranged first reinjection water pipe with reinjection water inlets at both ends of the axial direction. The first reinjection water pipe has multiple downward-facing reinjection water pipe branches evenly arranged along the axial direction. The multiple reinjection water pipe branches are connected to the tops of multiple vertical second reinjection water pipes. The bottom of the multiple second reinjection water pipes is filled with water from a coarse sand filter layer. A multi-media filter layer is laid at the bottom of the coarse sand filter layer. A bottom layer of permeation is laid at the bottom of the multi-media filter layer. A clean water outlet is provided at the bottom of the bottom layer of permeation.

[0064] The bottom of the multi-media filter layer is provided with a first backwash pipe in the horizontal direction. The first backwash pipe has backwash water inlets at both ends in the radial direction. The first backwash pipe has multiple backwash pipe branches with upward openings in the radial direction. The multiple backwash pipe branches are connected to multiple second backwash pipes in the vertical direction.

[0065] Specifically, the acid injection device for precise flow control includes an acid liquid storage bottle with an acid liquid outlet at the bottom. The acid liquid outlet is connected to one end of a first acid injection pipe, and the other end of the first acid injection pipe is connected to the top of a second acid injection pipe. The lower half of the second acid injection pipe is located in a filter pipe inside a deep well.

[0066] The bottom of the second acid injection pipe is connected to the top of the acid injection pump, and the part of the second acid injection pipe located inside the water filter pipe is also provided with small holes.

[0067] Compared with the prior art, the present invention has the following technical effects:

[0068] (I) This invention starts from the whole cycle of deep reinjection of high-salinity mine water. After fully revealing the three fundamental causes of chemical blockage caused by deep reinjection of high-salinity mine water, it proposes methods for water quality control before reinjection, pre-injection water treatment, and rapid removal of chemical blockage during reinjection, thereby controlling the risk of chemical blockage during reinjection to the greatest extent.

[0069] (II) The method in this invention can be directly applied to deep reinjection sites with high mineralization, solving the problems of reduced reinjection efficiency and reduced reinjection water volume caused by chemical blockage during the reinjection process, strengthening the deep storage and circulation of high mineralization mine water, and ultimately solving the problems of large scale and high cost of surface treatment of high mineralization mine water.

[0070] (III) The deep reinjection high-mineralization mine water full-cycle control chemical blockage system of the present invention adopts a smart mixing control device for reinjection water quality control before reinjection, an iron-manganese multi-media layered filtration pool for iron and manganese ion removal, and an acid injection device with precise flow control for efficient removal of chemical blockage in high-temperature and high-pressure environment, thus solving the problem of chemical blockage that is easy to occur in high-mineralization mine water during reinjection. Attached Figure Description

[0071] Figure 1(a) shows the relationship between the adsorption capacity of coconut shell biochar for iron and manganese ions and time.

[0072] Figure 1(b) shows the relationship between the adsorption capacity of fly ash ceramsite for iron and manganese ions and time.

[0073] Figure 1(c) shows the relationship between the adsorption capacity of iron and manganese ions by black sandy soil and time.

[0074] Figure 2 This is a schematic diagram of an indoor water-rock interaction simulation test.

[0075] Figure 3 Scanning electron microscope image of chemical blockage material in the target rock.

[0076] Figure 4 This is a schematic diagram of a deep reinjection system for high-salinity mine water.

[0077] Figure 5(a) is a schematic diagram of the intelligent mixing control device for reinjected water quality.

[0078] Figure 5(b) is a schematic diagram of the structure of section AA in Figure 5(a) from below.

[0079] Figure 5(c) Schematic diagram of the water quality detector panel.

[0080] Figure 6 This is a schematic diagram of the structure of an iron-manganese multi-media stratified filter.

[0081] Figure 7 A schematic diagram of the acid injection device for precise flow control.

[0082] The meanings of the labels in the diagram are as follows: 1-Intelligent mixing control device for reinjected water quality, 2-Iron-manganese multi-media stratified filtration tank, 3-Acid injection device with precise flow control, 4-Water tank, 5-Water storage tank, 6-Deep well.

[0083] 101-Mine water inlet, 102-Mixing tank drain, 103-Second water supply pipe, 104-Mixing tank, 105-Outer compartment, 106-Mixing chamber, 107-First mine water inlet pipe, 108-First groundwater inlet pipe, 109-Second mine water inlet pipe, 110-Second groundwater inlet pipe, 111-Groundwater inlet, 112-Mine water inlet channel, 113-Groundwater inlet channel, 114-Agitator, 115-Water quality detection probe, 116-First gap, 117-Second gap, 118-Drainage channel, 119-Nozzle.

[0084] 201-Reinjection water inlet, 202-Clean water outlet, 203-Fourth water supply pipe, 204-First reinjection water pipe, 205-Reinjection water pipe branch, 206-Second reinjection water pipe, 207-Coarse sand filter layer, 208-Multi-media filter layer, 209-Bottom layer infiltration layer, 210-Iron and manganese concentration monitor, 211-First backwash pipe, 212-Backwash water inlet, 213-Backwash pipe branch, 214-Second backwash pipe.

[0085] 301 - Acid outlet, 302 - Acid storage bottle, 303 - First acid injection tube, 304 - Acid injection pump.

[0086] 401 - Water pump, 402 - First water delivery pipe.

[0087] 501 - Water outlet of water storage tank, 502 - Third water supply pipe.

[0088] 601 - Second acid injection pipe, 602 - Water filter pipe.

[0089] 10401 - Stirring controller, 10402 - Water quality detector, 10403 - Pressure sensor, 10404 - Air release valve.

[0090] 10901 - Mine water pipe branch port, 10902 - Mine water regulating valve, 10903 - Mine water flow meter.

[0091] 11001 - Groundwater inlet pipe branch, 11002 - Groundwater regulating valve, 11003 - Groundwater flow meter.

[0092] 30301 - Acid injection flow control and monitoring device; 30302 - Valve.

[0093] 40201 - First water supply pipe branch.

[0094] 50201 - Third water supply pipe branch, 50202 - Third water supply pipe first branch, 50203 - Third water supply pipe second branch.

[0095] 60101-Small hole.

[0096] 5020301 - Water pipe controller.

[0097] The specific content of the present invention will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0098] It should be noted that, unless otherwise specified, all components, software, modules, instruments, and materials in this invention are based on components, software, modules, instruments, and materials known in the prior art. For example, the inductively coupled ion chromatograph is a known inductively coupled ion chromatograph; the online physicochemical index monitoring probe is a known online physicochemical index monitoring probe;

[0099] The PHREEQC numerical simulation software is the known PHREEQC numerical simulation software; the Interactive module is the known Interactive module.

[0100] The overall technical concept of this invention is as follows: High-salinity mine water in western mining areas not only contains various soluble conventional ions, but also has high concentrations of iron and manganese ions. When reinjected from shallow to deep layers, this high-salinity mine water will interact with the deep aquifer, forming a new hydrogeochemical equilibrium. This not only produces new carbonate and sulfate precipitates, but also oxides and hydroxides of iron and manganese, clogging the chemical pores of the rock and ultimately reducing the mine water reinjection capacity.

[0101] Before designing a deep mine water reinjection system, three reasons were considered for chemical blockage in high-salinity mine water reinjection: ① Incompatibility between the reinjection water quality and the deep groundwater quality, leading to precipitation due to mixing; ② High iron and manganese ion content in the reinjection water, resulting in oxidation reactions during reinjection and the formation of iron- and / or manganese-containing chemical precipitates; ③ Increased temperature and pressure in the deep environment, leading to increased carbonate concentration in the water, which easily combines with cations in the reinjection water to form calcium carbonate precipitates. Based on these causes of chemical blockage, this invention provides a full-cycle chemical blockage control method and system, including pre-injection water quality control, removal of iron and manganese elements at the front end, and timely removal of precipitates during reinjection. This will significantly reduce the probability of chemical precipitation before and during the reinjection of high-salinity mine water.

[0102] It should be noted that the principle of minimizing chemical precipitation in this invention is to select the sample with the smallest amount of chemical precipitation.

[0103] In this invention, groundwater refers to the water in the target reinjected aquifer.

[0104] In this invention, high-mineralized mine water refers to mine water with a salt content higher than 1000 mg / L.

[0105] In this invention, pH refers to acidity or alkalinity.

[0106] In this invention, TDS refers to total dissolved solids.

[0107] In this invention, HCO3 is determined by chemical method. - The concentration of HCO3 is determined using commonly used chemical methods. - The concentration.

[0108] In this invention, Xiaobaodang No. 1 Coal Mine is located in the southwest of Shenmu City, Yulin City, Shaanxi Province, and is administratively under the jurisdiction of Dabaodang Town, Shenmu City, Yulin City. The mining area is located at the northern end of the Loess Plateau in northern Shaanxi and the southeastern edge of the Mu Us Desert. Most of the area is covered by Quaternary aeolian semi-fixed and fixed sand dunes, with a predominantly aeolian desert hilly landform, generally trending from high in the southwest to low in the east. The main aquifers of the mine are classified as follows: Quaternary Upper Pleistocene Salausu Formation pore-filled aquifer, weathered bedrock fissure confined aquifer, Middle Jurassic Anding Formation bedrock fissure confined aquifer, Middle Jurassic Zhiluo Formation bedrock fissure confined aquifer, and Middle Jurassic Yan'an Formation bedrock fissure confined aquifer. The main source of mine water is the Yan'an Formation confined aquifer.

[0109] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0110] Example 1:

[0111] This embodiment presents a method for controlling chemical blockage throughout the entire cycle of deep reinjection of high-salinity mine water. The method includes the following steps:

[0112] Step 1: Water sample collection and testing, and monitoring of basic environmental indicators:

[0113] The collection and testing of high-salinity mine water samples and target aquifer water samples for reinjection, as well as the monitoring of basic environmental indicators of the target aquifer, including temperature and pH, are carried out on-site using online physicochemical monitoring probes deployed in the borehole.

[0114] The proposed high-salinity mine water samples were collected from different locations underground, including the roof water seepage point, the drainage borehole, and the central water reservoir. The target aquifer water samples were collected during drilling. After the proposed high-salinity mine water samples were collected underground or the target aquifer water samples were collected through the borehole, the physicochemical properties of the water samples (pH, temperature, and TDS) were tested on-site using a portable multi-functional analyzer. The pH of the target aquifer water sample was measured to be 8.22, and the temperature was 60℃.

[0115] Table 1. Water quality analysis of high-salinity mine water samples to be reinjected.

[0116]

[0117] After filtration, K+ samples from the proposed high-salinity mine water and the target aquifer water were analyzed in the laboratory using inductively coupled ion chromatography (ICC-CLC). + Na + Ca 2+ Mg 2+ SO4 2- and Cl - The concentration of HCO3 in the two water samples was determined by chemical methods. - The concentration of the high-mineralized mine water sample to be reinjected is shown in Table 1, and the water quality analysis of the target aquifer water sample to be reinjected is shown in Table 2.

[0118] Table 2. Water quality analysis of water samples from the target reinjected aquifer.

[0119]

[0120] Step 2: Conduct simulation tests to determine the quality of the reinjected water:

[0121] Based on the basic indicators of the target reinjection aquifer environment obtained in step one, a numerical model for the reinjection test of high-salinity mine water is constructed to simulate the test when the high-salinity mine water sample to be reinjected is mixed with the target reinjection aquifer water sample in different proportions.

[0122] Based on the operation of the experimental numerical model, the amount of chemical precipitation under different mixing ratios was quantitatively calculated. Based on the principle of minimizing the amount of chemical precipitation, a linear superposition model of the high-mineralization mine water sample to be reinjected and the target aquifer water sample was constructed to finally determine the water quality of the reinjected water.

[0123] Step two specifically includes the following steps:

[0124] Step 201: Using the Interactive module in the PHREEQC numerical simulation software, conduct simulation experiments with the ratios of the proposed high-salinity mine water sample to the target aquifer water sample being 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8, and 1:9. For each experiment, input the average concentration of the proposed high-salinity mine water sample and the concentrations of different ions in the target aquifer water sample.

[0125] The average concentration of different ions is obtained by calculating the average value of the different ion concentrations collected and detected in step one.

[0126] The temperature and pH values ​​set in the Interactive module are the parameters monitored in the target reinjection aquifer environment during step one, namely pH 8.24 and temperature 65℃.

[0127] In step 201, the simulation procedure related to the simulation experiment is as follows:

[0128] DATABASE C:\Program Files(x86)\USGS\Phreeqc Interactive\phreeqc.dat

[0129] SOLUTION 1

[0130] temp 65

[0131] pH 8.24

[0132] PE 4

[0133] redox PE

[0134] units mg / kgw

[0135] density 1

[0136] Na 534.6

[0137] Ca 19.22

[0138] Mg 1.33

[0139] S(6)44.62

[0140] Cl 228.97

[0141] Alkalinity 990.14

[0142] water 1#kg

[0143] SOLUTION 2

[0144] temp 60

[0145] pH 8.21

[0146] PE 4

[0147] redox PE

[0148] units mg / kgw

[0149] density 1

[0150] Na 7850.15

[0151] Ca 14511.02

[0152] Mg 894.06

[0153] S(6)2075.01

[0154] Cl 39739.84

[0155] Alkalinity 25.22

[0156] water 1#kg

[0157] MIX 1 1 0.1

[0159] 2 0.9.

[0160] Step 202: Based on the simulation experiment in step 201, obtain the mixing results of 9 sets of high-mineralization mine water samples to be reinjected and target aquifer water samples in different proportions, that is, obtain the chemical precipitation amount of 9 different substances, including 1 set of chemical precipitation of four types: calcium carbonate precipitation, magnesium carbonate precipitation, calcium sulfate precipitation and magnesium sulfate precipitation.

[0161] Table 3 Chemical precipitation amounts of two water samples under different mixing ratios

[0162]

[0163] Step 203: Sum the chemical precipitation amounts of the nine groups from Step 202 to obtain the total chemical precipitation amount in each group of experiments. The calculation results are shown in Table 3. Based on the principle of minimizing chemical precipitation, it can be analyzed that when the ratio of the proposed high-salinity mine water sample to the target aquifer water sample is 9:1, the minimum total chemical precipitation amount is 0.001580 mol / Kg. Therefore, a 9:1 ratio of the proposed high-salinity mine water sample to the target aquifer water sample is the optimal reinjection ratio.

[0164] The water mixed with the high-salinity mine water sample to be reinjected and the target aquifer water sample under the optimal reinjection ratio is the reinjected water.

[0165] Step 204: Based on the optimal reinjection ratio in Step 203, calculate K in the reinjected water by constructing a linear superposition model. + Na + Ca 2+ Mg 2+ SO4 2- Cl - and HCO3 - The concentrations of the seven ions can be determined using a linear superposition model:

[0166] C 回注 =K1×C 矿井水 +K2×C 地下水

[0167] In the formula:

[0168] C 回注 The concentration of a certain ion in the reinjected water is expressed in mg / L.

[0169] K1 represents the proportion of the high-salinity mine water sample to be reinjected in the optimal reinjection ratio obtained in the mixing test;

[0170] K2 represents the proportion of the target aquifer water sample in the optimal reinjection ratio obtained in the mixing test;

[0171] C 矿井水 To determine the K content in the high-salinity mine water sample to be reinjected + Na + Ca 2+ Mg 2+ SO4 2- Cl - or HCO3 - The average concentration, expressed in mg / L;

[0172] C 地下水 K was injected into the aquifer water sample for the target. + Na + Ca 2+Mg 2+ SO4 2- Cl - or HCO3 - Concentration, in mg / L.

[0173] The relevant results of the concentrations of the seven ions in the reinjected water obtained from the formula are shown in Table 4.

[0174] Table 4. Water quality analysis of high-salinity mine water samples to be reinjected, target aquifer water samples, and reinjected water.

[0175]

[0176] According to Table 4, the water quality parameters of the reinjected water can be obtained: K + and Na + The sum of the concentrations is 1266.16 mg / L, Ca 2+ The concentration was 1468.4 mg / L, Mg 2+ The concentration was 90.60 mg / L, SO4 2- The concentration was 247.66 mg / L, Cl - The concentration was 4180.06 mg / L, HCO3 - The concentration was 893.65 mg / L, the TDS was 8164.74 mg / L, and the pH was 8.24.

[0177] Step 3: Screen three types of filter media for removing iron and manganese ions from the reinjected water and determine the optimal ratio:

[0178] Step 2 has determined the concentrations of iron and manganese ions in the reinjected water. Before reinjection, a filtration test for iron and manganese ions is conducted to initially select three filter media with strong adsorption properties for iron and manganese ions and determine the optimal mixing ratio of the three filter media.

[0179] Furthermore, in step three, the optimal mixing ratio of the three filter media is coconut shell biochar: black sand: fly ash ceramsite = 80 wt.%: 10 wt.%: 10 wt.%.

[0180] Step three involves determining the optimal ratio as follows:

[0181] Step 301: Determine the concentration of iron ions in the reinjected water, which was determined in Step 2, to be 8.98 mg / L and the concentration of manganese ions to be 0.15 mg / L. Select filter media that simultaneously meets four conditions: easy to obtain, good permeability, strong adsorption capacity for iron and manganese ions, and the concentration of iron and manganese ions released in pure water is much lower than the concentration of iron and manganese ions in high-mineralization mine water.

[0182] In this embodiment, eight types of filter media were initially selected from three categories: soil around the mining area, waste recycling preparation materials, and activated carbon adsorption materials. The specific filter media are shown in Table 5.

[0183] Table 5. Alternative Filter Media Sources

[0184]

[0185] Indoor iron and manganese ion release and adsorption tests were conducted to determine the concentrations of iron and manganese ions released by eight filter media under blank conditions, as well as their removal rates. The results are shown in Table 6. The test results indicate that the concentrations of iron and manganese ions released by the eight materials under blank conditions were much lower than those of the high-salinity mine water sample to be reinjected, but there were differences in the removal rates of iron and manganese ions.

[0186] Table 6. Concentrations of iron and manganese ions released by different filter media and their removal rates.

[0187]

[0188] Overall, activated carbon filter media showed high removal rates for iron and manganese ions. However, among the three types of activated carbon filter media, coconut shell biochar had the highest removal rate, followed by fly ash ceramsite and loess, whose removal rates were also much higher than those of fine sand and black sand. Therefore, coconut shell biochar, fly ash ceramsite, loess, and black sand were initially selected as the four media for filter media.

[0189] Table 7. Permeability coefficients of eight filter media

[0190]

[0191] The permeability coefficients of these eight filter media were determined using indoor tests. The permeability coefficients of each filter media are shown in Table 7.

[0192] Based on the initial screening results of iron and manganese ion removal rates, the permeability coefficients of four media—coconut shell biochar, fly ash ceramsite, loess, and black sandy soil—were compared. The permeability coefficient of loess was on the order of 10. -5 The permeability coefficient of black sandy soil is on the order of 10. -3 A low permeability coefficient can easily cause clogging during the percolation process. Considering that the other two media, coconut shell biochar and fly ash ceramsite, both have low permeability coefficients and high removal rates for iron and manganese ions, and taking into account key factors such as the release concentration and removal rate of iron and manganese ions under blank conditions, coconut shell activated carbon, fly ash ceramsite, and black sand were ultimately selected as the filter media.

[0193] Step 302: Using the filter media selected in Step 301 as the medium, indoor shaking adsorption tests are conducted. 5g of filter media is mixed with 50ml of reinjection water, and the mixture is shaken for 5min, 10min, 30min, 120min, and 180min respectively. After shaking, the supernatant is filtered, and the concentrations of iron and manganese ions in the supernatant are measured. The adsorption capacity of the filter media for iron and manganese ions at different times is calculated based on the concentration difference. The formula for calculating the adsorption capacity is as follows:

[0194]

[0195] In the formula:

[0196] q t The amount adsorbed at time t is expressed in mg / kg.

[0197] C t The mass of iron or manganese ions in the supernatant at time t is expressed in mg.

[0198] C0 represents the initial mass of iron or manganese ions in the supernatant, expressed in mg.

[0199] m represents the mass of the filter media, expressed in kg.

[0200] Because the adsorption of iron and manganese ions by filter media undergoes a reverse process of desorption, the adsorption capacity at which the adsorption reaches equilibrium is considered the stable adsorption capacity of the filter media. Therefore, the adsorption capacity of iron and manganese ions by coconut shell biochar, fly ash ceramsite, and black sand over time was measured, and the results are shown in Figures 1(a), 1(b), and 1(c), respectively. Based on the stable adsorption capacity determined in Figures 1(a), 1(b), and 1(c), a predictive model for the relationship between stable adsorption capacity and maximum adsorption capacity was constructed, and the maximum adsorption capacity of a single medium was calculated. The predictive model for the relationship between stable adsorption capacity and maximum adsorption capacity is as follows:

[0201]

[0202] In the formula:

[0203] q t The maximum adsorption capacity is expressed in mg / kg.

[0204] q e To ensure stable adsorption capacity, the unit is mg / kg.

[0205] e is a numerical constant, the base of the natural logarithm function, which is 2.718.

[0206] n1 is the pseudo-first-order adsorption rate constant, and different filter media have fixed adsorption rate constants.

[0207] t represents time, in minutes.

[0208] Finally, the maximum adsorption capacities of coconut shell biochar for iron ions and manganese ions were calculated to be 92.41 mg / kg and 85.84 mg / kg, respectively; the maximum adsorption capacities of fly ash ceramsite for iron ions and manganese ions ...

[0209] Step 303: The maximum adsorption capacity of the single medium for iron ions and manganese ions determined in step 302 is arranged in descending order, namely coconut shell biochar, black sand and fly ash ceramsite. Therefore, coconut shell biochar is determined to be the main adsorbent, black sand as the first co-adsorbent, and fly ash ceramsite as the second co-adsorbent.

[0210] Then, based on the ratios of primary adsorbent:first co-adsorbent:second co-adsorbent of 8:1:1, 7:2:1, 6:3:1, 5:4:1, and 4:5:1, respectively, the superimposed adsorption capacity of iron and manganese ions when the three filter media are mixed in different proportions is calculated. The relevant formula for calculating the superimposed adsorption capacity of iron and manganese ions when mixed is as follows:

[0211] q 混 =X1q 铁e *X2q 铁e +X3q 铁e +X1q 锰e *X2q 锰e +X3q 锰e

[0212] In the formula:

[0213] q 混 The adsorption capacity of the three filter media for iron and manganese ions when mixed is expressed in mg / kg.

[0214] q 铁e The amount of iron ions adsorbed by the filter media when adsorption is stable is expressed in mg / kg.

[0215] q 锰e The amount of manganese ions adsorbed by the filter media when adsorption is stable is expressed in mg / kg.

[0216] X1, X2, and X3 represent the proportions of the primary adsorbent, the first co-adsorbent, and the second co-adsorbent, respectively, when mixed.

[0217] Table 8 shows the combined adsorption capacity of the three filter media for iron and manganese ions when mixed in different proportions. Based on the calculated combined adsorption capacity of the filter media under different proportions, the optimal mixing ratio of the three filter media is 8:1:1. At this ratio, the adsorption capacity of the filter media for iron and manganese ions in the reinjected water reaches its maximum, which is 155.62 mg / kg. Therefore, the final mass fractions of coconut shell biochar, black sand, and fly ash ceramsite in the iron-manganese multi-media stratified filtration tank are determined to be 80%, 10%, and 10%, respectively.

[0218] Table 8 shows the combined adsorption capacity of iron and manganese ions for three different proportions of filter media.

[0219]

[0220] Step 4: Indoor testing to determine the main chemical substances causing the reinjection blockage:

[0221] First, the iron and manganese ions in the reinjection water are treated using the three types of filter media described in step three to obtain treated reinjection water.

[0222] Secondly, before reinjecting the treated reinjection water, a simulation test of the interaction between the reinjection water and the target rock was conducted indoors. The chemical substances that caused the blockage were identified in the rock after the simulation test using scanning electron microscopy, energy dispersive spectroscopy, and mineral composition analysis.

[0223] Finally, the treated reinjection water is reinjected.

[0224] In this embodiment, the target rock is a rock sample taken from the target reinjection aquifer during the drilling stage.

[0225] In this specific embodiment, 500ml of reinjected water and 500g of target rock were placed in a beaker and allowed to stand. Then, rocks of a different type than the target rock were added to the beaker, and the mixture was prepared according to a mass ratio of 10:1 between the target rock and the different rock types. The mixture was then left to stand in the beaker to simulate the water-rock interaction process. The water-rock indoor simulation diagram is shown below. Figure 2 As shown in the figure. A 10ml water sample was taken daily from the settled beaker to monitor water quality changes. The experiment was stopped when the water quality remained stable. The target rock sample was then removed, crushed using a crusher, sieved, and analyzed for mineral composition using X-ray diffraction (XRD). Specific analysis results are shown in Table 9.

[0226] Table 9. Major minerals in the target rock

[0227] Mineral types quartz Potassium feldspar Sodium feldspar dolomite calcite Proportion(%) 59.9 9.6 3.76 14.37 12.37

[0228] In addition, the target rock sample was prepared into thin sections and tested using a scanning electron microscope. The test results are as follows: Figure 3As shown. Simultaneously, energy dispersive spectroscopy (EDS) analysis was performed on the locations of pore blockages in the target rock to obtain the proportions of each element in the blockage material. Finally, based on the ratios of different elements in the EDS, the chemical composition of the blockage was determined and cross-validated with the analysis results of the mineral composition. Ultimately, the type of chemical blockage material was identified, and the test results showed that the chemical blockage material was CaCO3.

[0229] Step 5: Select the acid and calculate the dosage to accurately remove the chemical precipitate.

[0230] Based on the chemical substance causing the blockage identified in step four, select the matching acid type, and determine the final amount of acid based on the acid concentration, the length and radius of the reinjection pipe during actual use.

[0231] In this embodiment, since the chemical blockage substance determined in step four is calcium carbonate, 10 wt.% dilute hydrochloric acid is selected as the reactant to remove the chemical blockage substance. The amount of acid injected is calculated based on the length and cross-sectional area of ​​the filter pipe; the cross-sectional area of ​​the filter pipe used for on-site reinjection is 0.025 m². 2 The filter pipe is 15m long, therefore the storage capacity inside the filter pipe is calculated to be 0.0375m. 3 Based on the required concentration of diluted hydrochloric acid being 10 wt.%, the required mass of concentrated hydrochloric acid with a concentration of 36 wt.% can be calculated.

[0232] Example 2:

[0233] This embodiment provides a system for controlling chemical blockage throughout the entire cycle of deep reinjection of high-salinity mine water. This system is used to implement the method for controlling chemical blockage throughout the entire cycle of deep reinjection of high-salinity mine water given in Embodiment 1.

[0234] The system includes an intelligent mixing and control device for reinjected water quality 1, an iron-manganese multi-media stratified filtration tank 2, and an acid injection device with precise flow control 3, wherein:

[0235] The intelligent mixing control device 1 for reinjected water quality is used to execute step two.

[0236] The iron-manganese multi-media stratified filter tank 2 is used to perform step three.

[0237] The acid injection device 3, which precisely controls the flow rate, is used to perform step five.

[0238] As a preferred embodiment of this invention, such as Figure 4As shown, the system also includes a water tank 4, inside which a water pump 401 is installed. The water pump 401 is connected to one end of a first water supply pipe 402. The other end of the first water supply pipe 402 is connected to the mine water inlet 101 of the intelligent mixing control device 1 for reinjected water quality. The bottom of the intelligent mixing control device 1 for reinjected water quality is also provided with a mixing tank drain outlet 102. The mixing tank drain outlet 102 is connected to one end of a second water supply pipe 103. The other end of the second water supply pipe 103 is connected to a water storage tank 5.

[0239] The water storage tank 5 is also equipped with a water storage tank outlet 501, which is connected to the third water supply pipe 502. The third water supply pipe 502 is equipped with a third water supply pipe branch port 50201, which is connected to one end of the first branch of the third water supply pipe 50202 and one end of the second branch of the third water supply pipe 50203, respectively.

[0240] The first water supply pipe 402 is also provided with a first water supply pipe branch port 40201, which is connected to the other end of the first branch of the third water supply pipe 50202.

[0241] The other end of the second branch of the third water supply pipe 50203 is connected to the reinjection water inlet 201 in the iron-manganese multi-media stratified filter tank 2; a water supply pipe controller 5020301 is installed on the second branch of the third water supply pipe 50203, and the water supply pipe controller 5020301 is located between the branch of the third water supply pipe 50201 and the reinjection water inlet 201.

[0242] The iron-manganese multi-media stratified filtration tank 2 is also equipped with a clean water outlet 202, which is connected to one end of the fourth water supply pipe 203, and the other end of the fourth water supply pipe 203 is connected to the underground deep well 6.

[0243] The deep well 6 is also equipped with a second acid injection pipe 601, which is connected to the acid output port 301 in the acid injection device 3 that precisely controls the flow rate.

[0244] As a preferred embodiment of this invention, as shown in Figures 5(a) and 5(b), the intelligent mixing control device 1 for reinjected water quality includes a mixing tank 104, an outer chamber 105 inside the mixing tank 104, and a top-open mixing cavity 106 formed by a top-open cylinder inside the outer chamber 105.

[0245] The inner wall of the mixing chamber 106 is provided with a first mine water inlet pipe 107 and a first groundwater inlet pipe 108; a plurality of nozzles 119 are evenly provided on the first mine water inlet pipe 107 and the first groundwater inlet pipe 108 respectively.

[0246] The top of the first mine water inlet pipe 107 is open, and the bottom of the first mine water inlet pipe 107 is connected to the mine water pipe branch port 10901 on the second mine water inlet pipe 109. One end of the second mine water inlet pipe 109 is connected to the mine water inlet 101 on the outside of the bottom of the mixing tank 104, and the other end of the second mine water inlet pipe 109 is connected to the bottom of the mixing chamber 106.

[0247] The top of the first groundwater inlet pipe 108 is open, the bottom of the first groundwater inlet pipe 108 is connected to one end of the second groundwater inlet pipe 110, and the other end of the second groundwater inlet pipe 110 is connected to the groundwater inlet 111 on the outside of the bottom of the mixing tank 104.

[0248] The second groundwater inlet pipe 110 is also equipped with a groundwater inlet pipe branch 11001, which is connected to the bottom of the mixing chamber 106.

[0249] The channel formed by the mine water inlet 101, the second mine water inlet pipe 109, the mine water pipe branch port 10901, the first mine water inlet pipe 107, and the mixing chamber 106 is the mine water inlet channel 112; the channel formed by the mine water inlet 101, the second mine water inlet pipe 109, and the mixing chamber 106 is also the mine water inlet channel 112.

[0250] The channel formed by the groundwater inlet 111, the second groundwater inlet pipe 110, the first groundwater inlet pipe 108, and the mixing chamber 106 is the groundwater inlet channel 113; the channel formed by the groundwater inlet 111, the second groundwater inlet pipe 110, the groundwater inlet pipe branch 11001, and the mixing chamber 106 is also the groundwater inlet channel 113.

[0251] A stirrer 114 is installed inside the mixing chamber 106. Water quality detection probes 115 are respectively installed on the bottom of the stirrer 114 and on the inner wall of the bottom of the mixing tank 104. A stirring controller 10401 and a water quality detector 10402 are also installed on the outer wall of the mixing tank 104. The water quality detector 10402 is a known water quality detector, and its panel is shown in Figure 5(c).

[0252] The top of the mixing tank 104 is also equipped with a pressure tester 10403 and a vent valve 10404, which are connected to each other. When the pressure tester 10403 detects that the pressure in the mixing chamber 106 is too high, the vent valve 10404 opens to release pressure and eliminate safety hazards.

[0253] The bottom of the mixing tank 104 is also provided with a mixing tank drain outlet 102. A first gap 116 is provided between the top of the outer compartment 105 and the top of the mixing chamber 106. A second gap 117 is provided between the inner side wall of the mixing tank 104 and the outer side wall of the mixing chamber 106. The channel formed by the first gap 116, the second gap 117 and the mixing tank drain outlet 102 is a drainage channel 118.

[0254] The second mine water inlet pipe 109 has a mine water regulating valve 10902 and a mine water flow meter 10903 sequentially installed between the mine water inlet 101 and the bottom of the mixing tank 104. The second groundwater inlet pipe 110 has a groundwater regulating valve 11002 and a groundwater flow meter 11003 sequentially installed between the groundwater inlet 111 and the bottom of the mixing tank 104. The combined use of the mine water regulating valve 10902 and the mine water flow meter 10903, as well as the groundwater regulating valve 11002 and the groundwater flow meter 11003, can strictly control the ratio of mine water to groundwater. After the mine water and groundwater enter the mixing tank 104, they are mixed inside the mixing chamber 106 while being fully stirred by the agitator 114.

[0255] As a preferred embodiment of this invention, such as Figure 6 As shown, the iron-manganese multi-media stratified filter tank 2 includes a horizontally arranged first reinjection water pipe 204. Reinjection water inlets 201 are provided at both axial ends of the first reinjection water pipe 204. Multiple downward-opening reinjection water pipe branches 205 are evenly arranged along the axial direction of the first reinjection water pipe 204. These branches 205 are connected one-to-one with the tops of multiple vertically arranged second reinjection water pipes 206. The bottom of the multiple second reinjection water pipes 206 is a coarse sand filter layer 20. 7. Water injection: A multi-media filter layer 208 is laid at the bottom of the coarse sand filter layer 207, and a bottom permeation layer 209 is laid at the bottom of the multi-media filter layer 208. A clean water outlet 202 is provided at the bottom of the bottom permeation layer 209. The second reinjection water pipe 206 is evenly distributed at the upper end of the iron-manganese multi-media layered filter tank 2. After the reinjection water enters, it is first filtered through the coarse sand filter layer 207. On the one hand, it can achieve the purpose of even infiltration of reinjection water, and on the other hand, it can remove fine suspended solids in the reinjection water.

[0256] A metal and manganese concentration monitor 210 is installed at the bottom of the multi-media filter layer 208. After the multi-media stratified filter tank 2 has been running for a period of time, the adsorption capacity of the filter media for metal and manganese ions will gradually decrease. At this time, the concentration of metal and manganese ions at the purified water outlet 202 will gradually increase. When the metal ion concentration is greater than 0.3 mg / L or the manganese ion concentration is greater than 0.1 mg / L, it exceeds the limit of the reinjection water. At this time, the filter media in the multi-media filter layer 208 should be replaced in time.

[0257] The bottom of the multi-media filter layer 208 is provided with a horizontal first backwash pipe 211. Backwash water inlets 212 are located at both radial ends of the first backwash pipe 211. Multiple upward-opening backwash pipe branches 213 are evenly arranged radially along the first backwash pipe 211, and these branches are connected one-to-one with multiple vertical second backwash pipes 214. After filtration for a period of time, the filter media contains iron and manganese oxides or hydroxides, causing blockage of the pores in the multi-media filter layer 208. At this time, pure water is introduced through the backwash water inlets 212 to backwash the filter media, thereby improving the removal efficiency of iron and manganese ions.

[0258] When using the iron-manganese multi-media stratified filter tank 2, the filter media is loaded into the multi-layer filter layer 208 after the proportion is determined according to the method in Example 1. First, the reinjection water enters evenly through the reinjection water inlet 201 of the iron-manganese multi-media stratified filter tank 2, and then passes through the coarse sand filter layer 207, the multi-media filter layer 208 and the bottom permeation layer 209 in sequence. Finally, the reinjection water after the manganese ions and iron ions have been adsorbed is discharged from the clean water outlet 202.

[0259] As a preferred embodiment of this invention, such as Figure 7 As shown, the acid injection device 3 for precise flow control includes an acid liquid storage bottle 302. The bottom of the acid liquid storage bottle 302 is provided with an acid liquid outlet 301. The acid liquid outlet 301 is connected to one end of the first acid injection pipe 303. The other end of the first acid injection pipe 303 is connected to the top of the second acid injection pipe 601. The lower half of the second acid injection pipe 601 is located in the filter pipe 602 inside the deep well 6.

[0260] The first acid injection pipe 303 is equipped with an acid injection flow control and monitoring device 30301 and a valve 30302. The acid injection flow control and monitoring device 30301 is used to monitor the flow rate of acid injected into the deep well 6.

[0261] The bottom of the second acid injection pipe 601 is connected to the top of the acid injection pump 304. A small hole 60101 is also provided on the portion of the second acid injection pipe 601 located inside the water filter pipe 602. The acid injection pump 304 is used to reinject acid into the deep well 6. The small hole 60101 prevents acid from flowing out from the top of the deep well 6, ensuring that the acid flows evenly into the water filter pipe.

[0262] Using a precisely controlled acid injection device 3, 10wt.% dilute hydrochloric acid is first transferred to the acid storage bottle 302. The acid flow rate is adjusted according to the reinjection water flow rate. After all the acid is injected, the acid in the storage bottle 302 is rinsed with clean water and then injected into the deep well 6. Valve 30302 is closed, allowing the acid to remain in the deep well 6 for 24–120 hours. Then, the deep well 6 is mechanically flushed, using the impact of water to promote the removal of sediment. Simultaneously, a special steel wire brush with the same inner diameter as the deep well 6 pipe and a weight attached to its bottom is placed into the well and repeatedly brushed until the reinjection water flow rate of the monitoring well begins to increase, indicating that the chemical blockage has been resolved, at which point acid injection is stopped.

Claims

1. A method for controlling chemical blockage throughout the entire lifecycle of deep reinjection of high-salinity mine water, the method comprising the following steps: Step 1: Water sample collection and testing, and monitoring of basic environmental indicators: The collection and testing of high-salinity mine water samples to be reinjected and water samples from the target aquifer, as well as the monitoring of basic environmental indicators of the target aquifer; characterized by: The basic indicators of the target reinjection aquifer environment include temperature and pH. Step 2: Conduct simulation tests to determine the quality of the reinjected water: Based on the basic indicators of the target reinjection aquifer environment obtained in step one, a numerical model for the reinjection test of high-salinity mine water is constructed to simulate the test when the high-salinity mine water sample to be reinjected is mixed with the target reinjection aquifer water sample in different proportions. Based on the operation of the experimental numerical model, the amount of chemical precipitation under different mixing ratios was quantitatively calculated. Based on the principle of minimizing the amount of chemical precipitation, a linear superposition model of the high-mineralization mine water sample to be reinjected and the target aquifer water sample was constructed to finally determine the water quality of the reinjected water. Step 3: Screen three types of filter media for removing iron and manganese ions from the reinjected water and determine the optimal ratio: Step 2 has determined the concentrations of iron and manganese ions in the reinjected water. Before reinjection, a filtration test for iron and manganese ions is conducted to initially select three filter media with strong adsorption capacity for iron and manganese ions and determine the optimal mixing ratio of the three filter media. Step 4: Indoor testing to determine the main chemical substances causing the reinjection blockage: First, the three types of filter media used in step three are used to treat the iron and manganese ions in the reinjection water to obtain treated reinjection water. Secondly, before reinjecting the treated reinjection water, a simulation test of the interaction between the reinjection water and the target rock was conducted indoors to identify the chemical substances that caused the blockage in the rock after the simulation test. Finally, the treated reinjection water is reinjected. Step 5: Select the acid and calculate the dosage to accurately remove the chemical precipitate. Based on the chemical substance causing the blockage identified in step four, select the matching acid type, and determine the final amount of acid based on the acid concentration, the length and radius of the reinjection pipe during actual use.

2. The method for controlling chemical blockage throughout the entire cycle of deep reinjection of high-salinity mine water as described in claim 1, characterized in that, In step one, the water samples of the high-salinity mine water to be reinjected are collected from different locations underground, including the roof water spray point, the drainage borehole, and the central water tank. The collection of water samples from the target reinjection aquifer was carried out during drilling. The high-salinity mine water samples to be reinjected and the target aquifer water samples, after filtration, were analyzed using inductively coupled ion chromatography (ICC) to detect the K content in both samples. + Na + Ca 2+ Mg 2+ SO4 2- and Cl - The concentration of HCO3 was determined using chemical methods in the high-salinity mine water samples to be reinjected and the target aquifer water samples. - The concentration.

3. The method for controlling chemical blockage throughout the entire cycle of deep reinjection of high-salinity mine water as described in claim 1, characterized in that, Step two, determining the quality of the reinjected water, specifically includes the following steps: Step 201: Using the Interactive module in the PHREEQC numerical simulation software, conduct a simulation test with a ratio of (1-9):(1-9) between the proposed high-salinity mine water sample and the target aquifer water sample. For each test, input the average concentration of the proposed high-salinity mine water sample and the concentration of different ions in the target aquifer water sample. The average concentration of the different ions is obtained by calculating the average value of the different ion concentrations collected and detected in step one; The temperature and pH values ​​set in the Interactive module are parameters monitored in step one of the target reinjection aquifer environment. Step 202: Based on the simulation experiment in step 201, obtain the mixing results of more than 8 groups of high-mineralization mine water samples with different proportions to be reinjected and target aquifer water samples, that is, obtain more than 8 groups of chemical precipitation amounts of different substances. Step 203: Sum the chemical precipitation amounts of each group in Step 202 to obtain the total chemical precipitation amount in each group of experiments. Based on the principle of minimizing chemical precipitation, the optimal reinjection ratio is determined by mixing the group of high-mineralization mine water samples with the minimum chemical precipitation amount with the target aquifer water samples. The water mixed with the high-salinity mine water sample to be reinjected and the target aquifer water sample under the optimal reinjection ratio is the reinjected water; Step 204: Based on the optimal reinjection ratio in Step 203, calculate K in the reinjected water by constructing a linear superposition model. + Na + Ca 2+ Mg 2+ SO4 2- Cl - and HCO3 - The concentrations of the seven ions can be determined using a linear superposition model: C 回注 =K1×C 矿井水 +K2×C 地下水 In the formula: Creinjection refers to the concentration of a certain ion in the reinjected water, expressed in mg / L. K1 represents the proportion of the high-salinity mine water sample to be reinjected in the optimal reinjection ratio obtained in the mixing test; K2 represents the proportion of the target aquifer water sample in the optimal reinjection ratio obtained in the mixing test; C mine water is a high-salinity mine water sample intended for reinjection. K + Na + Ca 2+ Mg 2+ SO4 2- Cl - or HCO3 - The average concentration, expressed in mg / L; C is groundwater that is reinjected into the aquifer water sample containing K. + Na + Ca 2+ Mg 2+ SO4 2- Cl - or HCO3 - Concentration, in mg / L.

4. The method for controlling chemical blockage throughout the entire cycle of deep reinjection of high-salinity mine water as described in claim 1, characterized in that, In step three, the optimal mixing ratio of the three filter media is coconut shell biochar: black sand: fly ash ceramsite = 80 wt.%: 10 wt.%: 10 wt.%.

5. The method for controlling chemical blockage throughout the entire cycle of deep reinjection of high-salinity mine water as described in claim 1, characterized in that, In step five, when the chemical substance is calcium carbonate or magnesium carbonate, the acid is dilute hydrochloric acid; when the chemical substance is calcium sulfate or magnesium sulfate, the acid is hydrofluoric acid.

6. A deep-layer reinjection system for high-salinity mine water with full-cycle control of chemical blockage, characterized in that, This system is used to perform the full-cycle chemical blockage control method for deep reinjection of high-salinity mine water as described in any one of claims 1 to 5; The system includes an intelligent mixing control device for reinjected water quality (1), an iron-manganese multi-media stratified filtration tank (2), and an acid injection device for precise flow control (3); The aforementioned intelligent mixing control device (1) for reinjected water quality is used to execute step two; The iron-manganese multi-media stratified filter tank (2) is used to perform step three; The acid injection device (3) with precise flow control is used to perform step five.

7. The deep reinjection high-salinity mine water full-cycle control chemical blockage system as described in claim 6, the system further includes a water tank (4), a water pump (401) is installed inside the water tank (4), and the water pump (401) is connected to one end of the first water delivery pipe (402), characterized in that, The other end of the first water supply pipe (402) is connected to the mine water inlet (101) of the intelligent mixing control device (1) for reinjection water quality. The bottom of the intelligent mixing control device (1) for reinjection water quality is also provided with a mixing tank drain outlet (102). The mixing tank drain outlet (102) is connected to one end of the second water supply pipe (103), and the other end of the second water supply pipe (103) is connected to the water storage tank (5). The water storage tank (5) is also provided with a water storage tank outlet (501), which is connected to the third water supply pipe (502). The third water supply pipe (502) is provided with a third water supply pipe branch port (50201), which is connected to one end of the first branch of the third water supply pipe (50202) and one end of the second branch of the third water supply pipe (50203). The first water supply pipe (402) is also provided with a first water supply pipe branch port (40201), which is connected to the other end of the first branch of the third water supply pipe (50202). The other end of the second branch (50203) of the third water supply pipe is connected to the reinjection water inlet (201) in the iron-manganese multi-media stratified filter tank (2); The iron-manganese multi-media layered filtration tank (2) is also equipped with a clean water outlet (202), which is connected to one end of the fourth water supply pipe (203), and the other end of the fourth water supply pipe (203) is connected to the underground deep well (6). The deep well (6) is also equipped with a second acid injection pipe (601), which is connected to the acid outlet (301) of the acid injection device (3) with precise flow control.

8. The deep reinjection high-salinity mine water full-cycle control chemical blockage system as described in claim 6, characterized in that, The intelligent mixing control device (1) for reinjected water quality includes a mixing tank (104), an outer chamber (105) inside the mixing tank (104), and a top-open mixing cavity (106) inside the outer chamber (105) formed by a top-open cylinder. The inner wall of the mixing chamber (106) is provided with a first mine water inlet pipe (107) and a first groundwater inlet pipe (108); a plurality of nozzles (119) are evenly provided on the first mine water inlet pipe (107) and the first groundwater inlet pipe (108); The top of the first mine water inlet pipe (107) is open, the bottom of the first mine water inlet pipe (107) is connected to the mine water pipe branch port (10901) on the second mine water inlet pipe (109), one end of the second mine water inlet pipe (109) is connected to the mine water inlet (101) on the outside of the bottom of the mixing tank (104), and the other end of the second mine water inlet pipe (109) is connected to the bottom of the mixing chamber (106). The top of the first groundwater inlet pipe (108) is open, the bottom of the first groundwater inlet pipe (108) is connected to one end of the second groundwater inlet pipe (110), and the other end of the second groundwater inlet pipe (110) is connected to the groundwater inlet (111) on the outside of the bottom of the mixing tank (104). The second groundwater inlet pipe (110) is also provided with a groundwater inlet pipe branch (11001), which is connected to the bottom of the mixing chamber (106). The channel formed by the mine water inlet (101), the second mine water inlet pipe (109), the mine water pipe branch (10901), the first mine water inlet pipe (107), and the mixing chamber (106) is the mine water inlet channel (112); the channel formed by the mine water inlet (101), the second mine water inlet pipe (109), and the mixing chamber (106) is also the mine water inlet channel (112). The channel formed by the groundwater inlet (111), the second groundwater inlet pipe (110), the first groundwater inlet pipe (108), and the mixing chamber (106) is a groundwater inlet channel (113); the channel formed by the groundwater inlet (111), the second groundwater inlet pipe (110), the groundwater inlet pipe branch (11001), and the mixing chamber (106) is also a groundwater inlet channel (113); The bottom of the mixing tank (104) is also provided with a mixing tank drain outlet (102), a first gap (116) is provided between the top of the outer compartment (105) and the top of the mixing chamber (106), and a second gap (117) is provided between the inner side wall of the mixing tank (104) and the outer side wall of the mixing chamber (106). The channel formed by the first gap (116), the second gap (117) and the mixing tank drain outlet (102) is a drainage channel (118).

9. The deep reinjection high-salinity mine water full-cycle control chemical blockage system as described in claim 6, characterized in that, The iron-manganese multi-media layered filter tank (2) includes a horizontally arranged first reinjection water pipe (204), with reinjection water inlets (201) at both ends of the first reinjection water pipe (204) along the axial direction. The first reinjection water pipe (204) has multiple downward-facing reinjection water pipe branch ports (205) evenly arranged along the axial direction. The multiple reinjection water pipe branch ports (205) are connected to the top of multiple vertical second reinjection water pipes (206) one by one. The bottom of the multiple second reinjection water pipes (206) is filled with water for a coarse sand filter layer (207). A multi-media filter layer (208) is laid at the bottom of the coarse sand filter layer (207). A bottom layer permeation layer (209) is laid at the bottom of the multi-media filter layer (208). A clean water outlet (202) is provided at the bottom of the bottom layer permeation layer (209). The bottom of the multi-media filter layer (208) is provided with a first backwash pipe (211) in the horizontal direction. The first backwash pipe (211) is provided with backwash water inlets (212) at both ends in the radial direction. The first backwash pipe (211) is provided with multiple backwash pipe branches (213) with upward openings in the radial direction. The multiple backwash pipe branches (213) are connected to multiple second backwash pipes (214) in the vertical direction.

10. The deep reinjection high-salinity mine water full-cycle control chemical blockage system as described in claim 6, characterized in that, The acid injection device (3) with precise flow control includes an acid liquid storage bottle (302), an acid liquid outlet (301) is provided at the bottom of the acid liquid storage bottle (302), the acid liquid outlet (301) is connected to one end of the first acid injection pipe (303), the other end of the first acid injection pipe (303) is connected to the top of the second acid injection pipe (601), and the lower half of the second acid injection pipe (601) is located in the filter pipe (602) in the deep well (6); The bottom of the second acid injection pipe (601) is connected to the top of the acid injection pump (304), and the part of the second acid injection pipe (601) located inside the water filter pipe (602) is also provided with a small hole (60101).

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