System and method for underground collaborative hardness removal treatment of mine water

Abstract

The present disclosure relates to a system and method for underground collaborative hardness removal treatment of mine water. The system includes an underground water reservoir and a dosing unit. The system can utilize the underground space to achieve collaborative removal of suspended matter and hardness ions in mine water, effectively improving the overall efficiency and purification effect of mine water treatment, which is conducive to reducing the use of chemical agents, reducing treatment costs, avoiding the risk of equipment blockage and scaling caused by agent residues and excessively hard water quality, extending the service life of the system, and also helping to reduce sludge treatment needs and reduce environmental burdens. The purified water obtained after treatment can meet the needs of production, dust reduction, and fire fighting water, significantly improving the water resource reuse rate, and has broad application prospects.

Description

Technical Field

[0001] The present disclosure relates to a system and method for collaborative underground hardness removal treatment of mine water. Background Art

[0002] Mine water, primarily composed of groundwater and formation water that enters tunnels during coal mining, typically contains large amounts of suspended matter (including particulate impurities such as coal dust and rock dust) and hardness ions (primarily calcium and magnesium ions). With increasing demands for water resource utilization, mine water recycling has become a crucial component of coal mining operations. Existing mine water treatment methods primarily rely on surface treatment systems, typically involving two steps: suspended matter removal and hardness treatment. These steps are achieved through processes such as sedimentation, filtration, flocculation, and softening with chemical addition. These methods suffer from complex processes, high costs, long settling times, large footprints, and high chemical consumption. For example, the existing ground treatment system requires the construction of a special pumping station to pump mine water to the ground, which has significant lifting costs and is prone to induce geological disasters such as ground subsidence and collapse, seriously damaging the ecological environment. To ensure the sedimentation effect, actual engineering applications often excessively add flocculants, coagulants and other chemical agents, which can easily cause residual membrane fouling, affect the smoothness and stability of the system, and increase maintenance costs. If the hardness is not removed sufficiently, hard scale will clog the pipes and equipment, and the effluent quality will be difficult to meet the reuse water standards. In addition, the sludge formed after ground treatment sedimentation usually has a high moisture content and still requires further concentration and dehydration treatment, which increases the difficulty of subsequent treatment. Summary of the Invention

[0003] The purpose of the present disclosure is to provide a system and method for underground coordinated hardness removal treatment of mine water.

[0004] In order to achieve the above-mentioned object, the present disclosure provides, in a first aspect, an underground coordinated hardness removal treatment system for mine water, the system comprising an underground water reservoir and a dosing unit;

[0005] The underground water reservoir is used to receive mine water containing suspended matter, and to make the mine water undergo a suspended matter collaborative hardness removal reaction under the condition of a pH value of 9.5 to 10.5, thereby obtaining purified water after the suspended matter and hardness ions are removed;

[0006] The dosing unit is used to provide a hardness remover to the mine water.

[0007] Optionally, the mineralization of the mine water is 1000~20000 mg / L, the turbidity is 0~10000 NTU, and the hardness in terms of CaCO3 is 0~2000 mg / L.

[0008] Optionally, the dosing unit includes a pre-reservoir dosing unit and / or an in-reservoir dosing unit, the pre-reservoir dosing unit is used to provide the de-hardening agent before the mine water enters the underground reservoir, and the in-reservoir dosing unit is used to provide the de-hardening agent to the mine water in the underground reservoir.

[0009] Optionally, the pre-storage drug adding unit includes a drug dispensing subunit, a drug storage subunit and a drug adding and mixing subunit;

[0010] The dispensing subunit is used to prepare the de-hardening agent according to the water quality parameters of the mine water;

[0011] The medicine storage subunit is used for temporarily storing the de-hardening agent;

[0012] The dosing and mixing subunit is used to provide the hardness remover for thorough mixing with the mine water.

[0013] Optionally, the dosing and mixing subunit is equipped with a pH value monitoring device and an automatic dosing controller;

[0014] The pH value monitoring device is used to monitor the pH value of the mine water in the dosing and mixing subunit in real time;

[0015] The automatic dosing controller is connected to the pH value monitoring device and is used to automatically adjust the dosage of the de-hardening agent according to the pH value of the mine water to ensure that the pH value of the mine water is maintained within a preset range.

[0016] Optionally, the underground water reservoir comprises a plurality of reservoir subunits connected in series, and the plurality of reservoir subunits are respectively connected to the dosing unit in the reservoir;

[0017] Each of the reservoir subunits provides a seepage path of no less than 20 m along the water flow direction, and is respectively equipped with a pH monitoring device, a turbidity monitoring device and a hardness monitoring device.

[0018] Optionally, the reservoir subunit is provided with a plurality of evenly distributed dosing points, and the dosing unit in the reservoir includes a plurality of dosing subunits connected to the dosing points in a one-to-one correspondence, and the dosing subunits are used to provide the de-hardening agent to the mine water in the reservoir subunit through the dosing points;

[0019] Preferably, the dosing subunit is equipped with an automatic dosing controller for automatically adjusting the dosage of the de-hardening agent according to the water quality of the mine water in the corresponding reservoir subunit.

[0020] Optionally, the purified water has a mineralization of 1000-20000 mg / L, a turbidity of <20 NTU, a hardness in terms of CaCO3 of 0-100 mg / L, and a pH of 9.5-10.5.

[0021] In a second aspect of the present disclosure, a method for treating mine water using the system described in the first aspect of the present disclosure is provided, the method comprising:

[0022] Mine water containing suspended matter is allowed to enter an underground reservoir, and a de-hardening agent is provided to the mine water in the underground reservoir through a dosing unit, so that the mine water undergoes a suspended matter collaborative de-hardening reaction under a pH value of 9.5 to 10.5, thereby obtaining purified water after the suspended matter and hardness ions are removed.

[0023] Optionally, the residence time of the mine water in the underground reservoir is 4 hours to 60 days.

[0024] Through the above-mentioned technical solution, the present invention utilizes the underground space to achieve the coordinated removal of suspended matter and hardness ions in mine water, effectively improving the overall efficiency and purification effect of mine water treatment, which is conducive to reducing the use of chemical agents and reducing treatment costs, avoiding the risk of equipment blockage and scaling caused by agent residues and excessively hard water quality, extending the service life of the system, and also helping to reduce sludge treatment needs and reduce the environmental burden. The purified water obtained after treatment can meet the needs of production, dust reduction and fire fighting water, significantly improving the water resource reuse rate, and has broad application prospects.

[0025] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0027] Figure 1 The present invention is a schematic diagram of the structure and flow of an underground mine water treatment system according to a specific embodiment.

[0028] Figure 2 The present invention is a structural diagram of an underground mine water treatment system according to a specific embodiment.

[0029] Figure 3 These are electron microscope comparison photos of hard scale particles in Example 1 and Comparative Example 1.

[0030] Figure 4 This is the hardness of the purified water outlet of Example 1.

[0031] Description of Reference Numerals

[0032] 1—dosing unit before the reservoir, 11—dosing point before the reservoir, 2—underground reservoir, 21—reservoir subunit, 22—dosing point in the reservoir, 3—dosing unit in the reservoir, 31—dosing subunit, 4—mine water, 5—purified water, 6—stratum. DETAILED DESCRIPTION

[0033] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0034] In a first aspect of the present disclosure, a system for synergistically removing hardness ions from underground mine water is provided, the system comprising an underground water reservoir and a dosing unit; wherein the underground water reservoir is used to receive mine water containing suspended matter, so that the mine water undergoes a synergistic removal reaction of suspended matter at a pH value of 9.5 to 10.5 to obtain purified water after the suspended matter and hardness ions are removed; the dosing unit is used to provide a de-hardening agent to the mine water.

[0035] In order to solve the problems of complex existing mine water treatment processes, high costs, long settling times, large floor space, and high reagent consumption, the present disclosure proposes an underground collaborative hardness removal system for mine water containing suspended matter. The system fully utilizes the underground space to achieve on-site treatment of mine water, uses the existing suspended matter resources in the mine water as crystal nuclei, promotes the faster precipitation of hardness ions (i.e., calcium and magnesium ions), effectively reduces the amount of reagents and treatment costs, improves treatment efficiency and purification effects, and the purified water obtained after treatment can be directly reused for production, dust reduction, fire fighting, etc. underground. The present disclosure is particularly applicable to water quality conditions with high suspended matter and hardness content in mine water. Specifically, the suspended matter content of the mine water can be 0~10000 mg / L, preferably 0~5000 mg / L; the mineralization can be 1000~20000 mg / L, preferably 1000~10000 mg / L, more preferably 1000~6000 mg / L; the turbidity can be 0~10000 NTU, preferably 0~5000 NTU; the hardness in terms of CaCO3 can be 0~2000 mg / L, preferably 0~1000 mg / L; further, in the mine water, the particle size of the suspended matter can be 0.1~100 μm, preferably 0.5~50 μm.

[0036] In one embodiment, the dosing unit may include a pre-reservoir dosing unit and / or an in-reservoir dosing unit to flexibly adapt to different water quality conditions and treatment requirements of mine water. The pre-reservoir dosing unit is used to provide the de-hardening agent before the mine water enters the underground reservoir, and the in-reservoir dosing unit is used to provide the de-hardening agent to the mine water in the underground reservoir. The pre-reservoir dosing unit and the in-reservoir dosing unit can be used alone or at the same time, and work together according to the treatment objectives and on-site conditions. For example, when the hardness of the mine water is low and the treatment load is small, only the pre-reservoir dosing unit can be used; when the hardness of the mine water is high and the reaction time is sufficient, only the in-reservoir dosing unit can be used; when the hardness of the mine water is high and the flow fluctuation is large, it is preferred to use the pre-reservoir dosing unit to initially reduce the hardness, and then supplement the dosing in the underground reservoir to ensure the treatment effect.

[0037] In a preferred embodiment, referring to Figure 1 , the system comprises:

[0038] The pre-storage dosing unit 1 is used to receive the mine water 4 containing suspended matter and provide a de-hardening agent to the mine water to adjust the pH value of the mine water to 9.5-10.5;

[0039] An underground water reservoir 2 is used to receive the mine water from the pre-reservoir dosing unit 1, and to subject the mine water to a suspended solids-coordinated hardness removal reaction at a pH value of 9.5 to 10.5, thereby obtaining purified water 5 after the suspended solids and hardness ions are removed;

[0040] The dosing unit 3 in the reservoir is used to provide a hardness remover to the mine water in the underground water reservoir 2 .

[0041] According to the present disclosure, the mine water can come from multiple water gushing points located in different ore layers or areas underground, and the mine water from different water gushing points may have different water qualities. In a specific embodiment, the system may also include a pre-sinking water tank, which is connected to the upstream of the pre-storage dosing unit 1 and is used to homogenize and pre-sink the mine water from multiple water gushing points, so that the mine water can reach a more uniform water quality before entering the pre-storage dosing unit 1, while reducing the content of large particle suspended matter in the mine water and reducing the solid load in the subsequent treatment stage. The pre-sinking water tank can be located in the initial collection area of ​​the mine water, and its capacity can be 200~8000 m 3 The pre-sinking water tank can be connected to the water inlet of the pre-sink dosing unit 1 through a water pipeline, and a conveying device can be configured on the pipeline to convey the mine water from the pre-sinking water tank to the pre-sink dosing unit 1.

[0042] The pre-storage dosing unit 1 provides preliminary de-hardening agent addition and mixing treatment for mine water containing suspended matter. By adjusting the water quality conditions, the suspended matter in the mine water provides an attachment surface for the precipitation of hardness ions such as calcium and magnesium. These suspended particles can serve as crystal nuclei, prompting calcium and magnesium ions to precipitate faster to form copolymers of low-solubility stable crystals such as calcium carbonate and magnesium hydroxide and suspended matter.

[0043] In a specific embodiment, the pre-storage dosing unit 1 may include a dosing subunit, a storage subunit, and a dosing and mixing subunit. The dosing subunit is used to prepare the de-hardening agent according to the water quality parameters of the mine water. The water quality parameters may include at least one of turbidity, hardness, and alkalinity. The dosing subunit can be connected to the water quality monitoring device of the underground water reservoir 2. When the water quality of the mine water is monitored to have a high suspended matter content, the concentration of the de-hardening agent can be prepared to a relatively low level. When the suspended matter content is low, the concentration of the de-hardening agent is automatically increased. The storage subunit is used to temporarily store the de-hardening agent to ensure the continuity of the de-hardening agent supply. The storage subunit can be equipped with a liquid level sensor to monitor the inventory of the de-hardening agent in real time so as to trigger replenishment when the de-hardening agent content is insufficient. The storage subunit can be connected to the dosing and mixing subunit via a metering pump or a control valve. The dosing and mixing subunit is used to provide the de-hardening agent and the mine water for thorough mixing. It can be set on the water inlet pipe for the mine water to enter the underground reservoir 2, and can be provided with a stirring component to enhance the mixing effect through mechanical or pneumatic stirring.

[0044] Furthermore, the dosing mixing subunit can also be configured with a pH value monitoring device and an automatic dosing controller, wherein the pH value monitoring device is used to monitor the pH value of the mine water in the dosing mixing subunit in real time, and the automatic dosing controller is connected to the pH value monitoring device and is used to automatically adjust the dosage of the de-hardening agent according to the pH value of the mine water to ensure that the pH value of the mine water remains within a preset range, thereby forming a closed-loop control, quickly responding to pH fluctuations in the mine water, avoiding insufficient or excessive dosage due to changes in water quality, and realizing intelligent and dynamic operation of the pre-reservoir dosing unit 1. The water outlet of the dosing mixing subunit is connected to the water inlet of the underground water reservoir 2 through a water pipeline, and a conveying device can be configured on the pipeline to convey the mine water from the pre-reservoir dosing unit 1 to the underground water reservoir 2.

[0045] The underground water reservoir 2 can be located downstream of the pre-reservoir dosing unit 1, which refers to a water storage space located in the stratum, for receiving mine water that has been mixed with a de-hardening agent, and completing the coordinated sedimentation and purification of suspended matter and hardness ions underground. Specifically, under suitable alkaline environment and water quality conditions, hardness ions are prone to precipitation reactions. When calcium and magnesium ions form precipitation on the surface of suspended matter particles, the specific gravity of these particles themselves increases, making it easier to settle under the action of gravity, thereby achieving the simultaneous removal of suspended matter and hardness ions in the mine water, and obtaining purified water after the suspended matter and hardness ions are removed. This coordinated sedimentation effect greatly improves the de-hardening and purification effect, reduces the residual amount of suspended matter and hardness ions in the water body, and, because the suspended matter particles act as carriers and reaction promoters in the coordinated de-hardening process, the precipitation reaction of hardness ions is accelerated, the demand for de-hardening agents in the system is relatively reduced, and the risk of equipment clogging and scaling caused by residual agents and excessively hard water quality is avoided, the operating cost of the system is reduced, and the service life of the system is extended. The sludge formed by the precipitation of hardness ions and suspended particles can remain in the underground reservoir 2, avoiding the additional processing burden of sludge transportation or surface treatment and the adverse impact on the environment.

[0046] The underground reservoir 2 can have a capacity of 100,000 to 5,000,000 cubic meters, providing ample residence time for the mine water. In one embodiment, the underground reservoir 2 can be a mined-out area, which refers to the space or cavity left underground after ore mining, possessing natural sedimentation, filtration, and water storage capabilities.

[0047] The underground water reservoir 2 can be designed as a one-stage or multi-stage series structure. Figure 2 As shown, the underground reservoir 2 includes a plurality of reservoir subunits 21 connected in series in the stratum 6, and the plurality of reservoir subunits 21 are connected in sequence through pipelines ( Figure 2 (not shown), and multiple reservoir subunits 21 are respectively connected to the dosing unit 3 in the reservoir. Furthermore, each of the reservoir subunits 21 provides a seepage path of not less than 20m along the direction of water flow to ensure that the mine water has sufficient residence time, and is respectively equipped with a water quality monitoring device, which may specifically include a pH monitoring device, a turbidity monitoring device, and a hardness monitoring device for real-time monitoring of key water quality parameters of the mine water. Based on these parameters, the dosage of the de-hardening agent can be adjusted in real time to ensure the effectiveness of the suspended matter synergistic de-hardening reaction. The reservoir subunit 21 can be provided with multiple evenly distributed dosing points for the addition of the de-hardening agent.

[0048] The in-reservoir dosing unit 3 precisely doses the de-hardening agent into the mine water in the underground reservoir 2. In one specific embodiment, the in-reservoir dosing unit 3 may include a dispensing subunit and a storage subunit, similar to those in the pre-reservoir dosing unit 1, as well as multiple dosing subunits 31. Each dosing subunit 31 is connected to a dosing point within the underground reservoir 2 (or reservoir subunit 21) to deliver the de-hardening agent to the mine water in the underground reservoir 2 (or reservoir subunit 21). Furthermore, each dosing subunit 31 is equipped with an automatic dosing controller that automatically adjusts the dosage of the de-hardening agent based on the water quality (including pH, hardness, turbidity, etc.) of the mine water in the corresponding reservoir subunit 21.

[0049] In the present disclosure, the de-hardening agent may be an alkaline agent, for example, at least one of Na2CO3, NaOH, lime, and gypsum. The de-hardening agent provided by the pre-storage dosing unit and the in-storage dosing unit may be the same or different.

[0050] In one embodiment, the disclosed underground coordinated mine water de-hardening treatment system further includes a control module for intelligently monitoring and regulating key units and treatment parameters in the mine water treatment process. This control module is connected to key equipment such as the pre-sink, pre-sump dosing unit, underground reservoir, and in-sump dosing unit. By integrating functions such as water quality monitoring, chemical dosing, and pH adjustment, it enables automated management and optimization of the entire mine water treatment system. In a preferred embodiment, the control module utilizes an artificial intelligence-based adaptive control algorithm that progressively optimizes control parameters (such as de-hardening agent dosage) at each node during operation and generates historical data records for subsequent analysis and system optimization.

[0051] The underground coordinated hardness removal treatment system for mine water disclosed herein is suitable for large-scale continuous treatment of mine water. Specifically, the system processing scale can reach 10 to 10,000 t / h. After treatment, most of the carbonate hardness in the mine water can be removed, and the effluent can be directly reused at the water point or post-treatment unit. Specifically, the suspended matter content of the purified water can be 0 to 50 mg / L, preferably 0 to 20 mg / L; the mineralization can be 1,000 to 20,000 mg / L, preferably 1,000 to 10,000 mg / L; the turbidity can be <20 NTU; the hardness in terms of CaCO3 can be 0 to 100 mg / L, preferably 5 to 50 mg / L; and the pH value can be 9.5 to 10.5.

[0052] The present invention realizes the rational utilization of underground space resources. There is no need to lift mine water from underground to the ground for treatment, which reduces the construction and operation costs of a large number of lifting pump stations and the occupation of ground resources. The hardness and suspended matter in the mine water can be removed synergistically without the addition of coagulants and flocculants. It is also beneficial to reduce sludge management needs and improve environmental benefits. The treated purified water can meet the needs of production, dust reduction and fire fighting water, greatly improving the water resource reuse rate. The entire treatment system can operate for a long time, efficiently and stably, and is more economical and energy-saving. It has the advantages of systematicity, source control, simple structure, flexible application, low cost, strong practicality, high control efficiency and good control effect.

[0053] In a second aspect of the present disclosure, a method for treating mine water using the system described in the first aspect of the present disclosure is provided, the method comprising:

[0054] Mine water containing suspended matter is allowed to enter an underground reservoir, and a de-hardening agent is provided to the mine water in the underground reservoir through a dosing unit, so that the mine water undergoes a suspended matter collaborative de-hardening reaction under a pH value of 9.5 to 10.5, thereby obtaining purified water after the suspended matter and hardness ions are removed.

[0055] In the embodiment described above where the dosing unit includes a pre-storage dosing unit and an in-storage dosing unit, the method may include the following steps S101-S102:

[0056] S101, mixing the mine water containing suspended matter with a de-hardening agent in a pre-storage dosing unit to adjust the pH value of the mine water to 9.5-10.5;

[0057] The method may further include homogenizing and pre-settling the mine water from multiple water gushing points in a pre-sinking tank before entering the pre-sink dosing unit. The mine water may have a suspended solids content of 0-10,000 mg / L, preferably 0-5,000 mg / L; a salinity of 1,000-20,000 mg / L, preferably 1,000-10,000 mg / L; a turbidity of 0-10,000 NTU, preferably 0-5,000 NTU; and a hardness in terms of CaCO3 of 0-2,000 mg / L, preferably 0-1,000 mg / L. The amount of the de-hardening agent used may be adjusted based on the total amount / quality of the mine water and the type of de-hardening agent. Specifically, the amount of the de-hardening agent used may be 0.005-0.2 parts by weight based on 100 parts by weight of the mine water. Furthermore, the method may also include: monitoring the pH value of the mine water, and automatically adjusting the dosage of the de-hardening agent according to the pH value of the mine water.

[0058] S102. Allow the mine water from the pre-reservoir dosing unit to enter the underground reservoir, and provide a de-hardening agent to the mine water in the underground reservoir through the in-reservoir dosing unit, so that the mine water undergoes a suspended matter collaborative de-hardening reaction under the condition of a pH value of 9.5-10.5, thereby obtaining purified water after the suspended matter and hardness ions are removed.

[0059] The residence time of the mine water in the underground reservoir is 4 hours to 60 days. The dosage of the de-hardening agent can be adjusted according to the total amount / water quality of the mine water and the type of de-hardening agent. Specifically, based on 100 parts by weight of the mine water, the dosage of the de-hardening agent can be 0.005 to 0.2 parts by weight. Furthermore, the method can also include: monitoring the pH value, turbidity, and hardness of the mine water, and automatically adjusting the dosage of the de-hardening agent according to the water quality of the mine water. The suspended solids content of the purified water can be 0 to 50 mg / L, preferably 0 to 20 mg / L; the mineralization can be 1000 to 20,000 mg / L, preferably 1000 to 10,000 mg / L; the turbidity can be <20 NTU; the hardness in terms of CaCO3 can be 0 to 100 mg / L, preferably 5 to 50 mg / L; and the pH value can be 9.5 to 10.5.

[0060] The method described in the second aspect of the present disclosure has all the beneficial effects of the system described in the first aspect of the present disclosure, which will not be repeated here.

[0061] The present disclosure is further illustrated by the following examples, but is not intended to limit the present disclosure.

[0062] Example 1

[0063] Deployed in a mining area Figure 1 and Figure 2 The system shown is for mine water treatment and includes:

[0064] The pre-sedimentation tank receives mine water from multiple water gushing points for homogenization and pre-sedimentation. The initial mineralization of the mine water is about 4000 mg / L, the turbidity is about 260 NTU, the hardness in terms of CaCO3 is about 310 mg / L, and the average particle size of the suspended matter is 8.098 μm.

[0065] The mine water in the pre-sink enters the dosing unit before the reservoir, and the de-hardening agent lime is prepared into a solution with a concentration of 5% by weight, and is added from the dosing point 11 before the reservoir through the automatic dosing controller to adjust the pH value of the mine water to 10.

[0066] The mine water from the pre-reservoir dosing unit enters the underground reservoir (pilot scale). The total volume of the underground reservoir is 230,000 cubic meters, the total length of the seepage path along the water flow direction is 34.2 meters, the mine water residence time is 4.025 days, and it is equipped with pH, ​​turbidity and hardness monitoring devices.

[0067] The de-hardening agent Na2CO3 is prepared into a solution with a concentration of 10 wt% in the dosing unit in the reservoir, and is added from multiple dosing points 22 in the underground reservoir through the dosing sub-unit 31. The dosage of the de-hardening agent is dynamically adjusted according to the water quality monitoring data to adjust the pH value of the mine water to 10.

[0068] After removing suspended solids and hardness ions, the purified water was collected from the underground reservoir. The mineralization was 4000 mg / L, the turbidity was 16 NTU, the hardness in terms of CaCO3 was 32 mg / L, and the pH value was 10. The water quality met the Class III standard of the "Surface Water Environmental Quality Standard" (GB20246-2006). The water was supplied to underground production and surface use through the water purification pool. The hard scale particles formed by the precipitation of hardness ions in the underground reservoir were collected, filtered and dried, and their morphology was observed by SEM electron microscopy. Figure 3 It can be seen that the hard scale particles are in the form of CaCO3 crystals and amorphous suspended matter aggregation (c) and encapsulation (d). The specific surface area, average particle size, median particle size, 10% particle size and 90% particle size are tested and listed in Table 1.

[0069] The hardness of the water discharged from the underground mine water treatment system of this embodiment after 168 hours of operation is as follows: Figure 4 As shown, it can be seen that a good hardness removal effect can be maintained in long-term operation. The processing scale is 2t / h and the average hardness removal rate is 89.67%.

[0070] Comparative Example 1

[0071] Mine water was treated according to the method of Example 1, except that clarified mine water was used for treatment, i.e., the mine water did not contain suspended matter, had an initial salinity of 4000 mg / L, a turbidity of 9 NTU, and a hardness of 310 mg / L in terms of CaCO3.

[0072] In this comparative example, the mineralization of the water produced by the underground reservoir is 4000 mg / L, the turbidity is 9 NTU, the hardness in terms of CaCO3 is 41 mg / L, and the pH value is 10. The hard scale particles formed by the precipitation of hardness ions in the underground reservoir are collected, filtered and dried, and their morphology is observed by SEM electron microscopy. Figure 3 It can be seen that the hard scale particles are basically regular cubic CaCO3 crystals (a) and (b). Their specific surface area, average particle size, median particle size, 10% particle size and 90% particle size are tested and listed in Table 1. The average hardness removal rate of this comparative example is 86.7%.

[0073] Comparative Example 2

[0074] Mine water was treated according to the method of Example 1, except that no de-hardening agent was added.

[0075] In this comparative example, the groundwater reservoir produced water had a mineralization of 4000 mg / L, a turbidity of 260 NTU, a hardness of 310 mg / L (calculated as CaCO₃), and a pH of 7.8. Suspended particles were collected from the groundwater reservoir, filtered, and dried. Their specific surface area, average particle size, median particle size, 10th percentile particle size, and 90th percentile particle size were measured and listed in Table 1.

[0076] Comparative Example 3

[0077] Mine water treatment was carried out according to the method of Example 1, except that the pH value of the mine water in the pre-reservoir dosing unit and the underground reservoir was adjusted to 9.

[0078] In this comparative example, the mineralization of the water produced from the underground reservoir is 4000 mg / L, the turbidity is 16 NTU, the hardness in terms of CaCO3 is 87 mg / L, the pH value is 9, and the average hardness removal rate is 72%.

[0079] Table 1

[0080]

[0081] As can be seen from Table 1, the hard scale particles of Example 1 have significantly improved particle size, indicating a more excellent suspended matter synergistic hardness removal treatment effect.

[0082] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0083] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0084] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A mine water underground collaborative hardness removal treatment system, characterized in that: The system includes an underground water reservoir and a dosing unit; The underground water reservoir is used to receive mine water containing suspended matter, and to make the mine water undergo a suspended matter collaborative hardness removal reaction under the condition of a pH value of 9.5 to 10.5, thereby obtaining purified water after the suspended matter and hardness ions are removed; The dosing unit is used to provide a hardness remover to the mine water; The dosing unit includes a pre-reservoir dosing unit and an in-reservoir dosing unit, wherein the pre-reservoir dosing unit is used to provide the de-hardening agent before the mine water enters the underground reservoir, and the in-reservoir dosing unit is used to provide the de-hardening agent to the mine water in the underground reservoir; The underground water reservoir is an underground goaf, and the underground water reservoir includes a plurality of reservoir subunits connected in series, and the plurality of reservoir subunits are respectively connected to the dosing unit in the reservoir; each of the reservoir subunits provides a seepage path of not less than 20m along the water flow direction, and is respectively equipped with a pH value monitoring device, a turbidity monitoring device and a hardness monitoring device; the reservoir subunit is provided with a plurality of evenly distributed dosing points, and the dosing unit in the reservoir includes a plurality of dosing subunits connected to the dosing points in a one-to-one correspondence, and the dosing subunit is used to provide the de-hardening agent to the mine water in the reservoir subunit through the dosing points, and the dosing subunit is equipped with an automatic dosing controller for automatically adjusting the dosage of the de-hardening agent according to the water quality of the mine water of the corresponding reservoir subunit; the residence time of the mine water in the underground water reservoir is 4h to 60 days; The system also includes a pre-sinking water tank, which is connected to the upstream of the pre-sink dosing unit and is used to homogenize and pre-sink the mine water; The mineralization of the mine water is 1000~20000 mg / L, the turbidity is 0~10000 NTU, and the total hardness in terms of CaCO3 is 0~2000 mg / L; the particle size of the suspended matter in the mine water is 0.1~100 μm; and the hardness remover is an alkaline agent.

2. The system according to claim 1, wherein: The pre-storage drug adding unit includes a drug dispensing subunit, a drug storage subunit and a drug adding and mixing subunit; The dispensing subunit is used to prepare the de-hardening agent according to the water quality parameters of the mine water; The medicine storage subunit is used for temporarily storing the hardness removing agent; The dosing and mixing subunit is used to provide the hardness remover for thorough mixing with the mine water.

3. The system according to claim 2, wherein: The dosing and mixing subunit is equipped with a pH value monitoring device and an automatic dosing controller; The pH value monitoring device is used to monitor the pH value of the mine water in the dosing and mixing subunit in real time; The automatic dosing controller is connected to the pH value monitoring device and is used to automatically adjust the dosage of the de-hardening agent according to the pH value of the mine water to ensure that the pH value of the mine water is maintained within a preset range.

4. The system according to claim 1, wherein: The purified water has a mineralization of 1000-20000 mg / L, a turbidity of <20 NTU, a hardness in terms of CaCO3 of 0-100 mg / L, and a pH of 9.5-10.5.

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