System and method for efficiently removing silicon in mine strong brine

Abstract

The invention provides a system and a method for efficiently removing silicon in mine strong brine, and solves the problems of large addition amount of a silicon removal agent, low silicon sedimentation speed and poor silicon removal effect under a high-salt condition in actual engineering. The system comprises a heterogeneous membrane device, a primary reverse osmosis device, a hardness and silicon removal integrated device, an ion exchange device, a secondary reverse osmosis device, an electric separation and concentration device, a filtering device, a silicon removal rapid sedimentation device, an evaporative crystallization device, a reuse water tank I and a reuse water tank II. The silicon removal by adopting various coupling processes has the advantage of integrally removing soluble silicon and colloidal silicon, can reduce the influence of salt effect, has the characteristics of low chemical consumption and high efficiency, can be well compatible with the existing mine water zero-discharge system, can effectively control the content of silicon entering an evaporative crystallization system, and has the advantages of low cost and high efficiency. The scaling risk of the subsequent evaporative crystallization process is reduced, the stable operation of the evaporative crystallization process is guaranteed, and the method has a wide application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of deep treatment of silicon in industrial wastewater, and particularly relates to a system and method for efficiently removing silicon from mine concentrated brine. Background Art

[0002] Mine concentrated brine is the concentrated brine obtained after reverse osmosis treatment of mine water generated during coal mining. In 2019, the production volume of mine water in China was approximately 7.1 billion m 3 , among which the mass concentrations of ions such as Na + , Ca 2+ , Cl - , SO4 2- are as high as 1000 - 4000 mg / L, and in some cases even exceed 40000 mg / L. Currently, the main process flow of zero-discharge treatment of mine water built in the northern region includes three links: desalination, secondary concentration, and evaporation crystallization for salt separation; among them, the core processes of the desalination and secondary concentration sections adopt reverse osmosis membrane concentration technology, and the auxiliary processes include pretreatment processes such as hardness and impurity removal to meet the requirements of reverse osmosis feed water. During the actual operation of the project, the impurities and silicon content in the concentrated brine after two-stage reverse osmosis concentration of mine water are high, which in turn affects the stability of the subsequent evaporation crystallization process and the quality of the crystalline salt. Therefore, effective measures need to be taken to remove silicon from the concentrated brine after reverse osmosis concentration before evaporation crystallization.

[0003] Silicon in mine brine mainly exists in the following four forms: (1) dissolved silicate compounds in molecular and ionic states, (2) unstable colloidal silicon, (3) adsorbed silicate compounds, and (4) relatively stable coarse-grained silicate compounds. Among them, silicon in the (3) and (4) forms can be effectively removed in the underground precipitation and filtration processes. The colloidal silicon in mine brine often changes with conditions. When there is more carbon dioxide in the water, and the pH value and temperature are lower, the originally dissolved silicic acid will precipitate out and further polymerize into colloidal polysilicic acid; when the pH value and temperature of the water are higher, this colloidal silicate compound will turn into dissolved silicon. The silicon in these two forms (i.e., the (1) and (2) forms) coexists in actual projects and will transform with different processes. Therefore, in actual water treatment processes, it is difficult to remove the silicon in these two forms. In actual mine brine zero-discharge projects, coagulation and precipitation are often used to remove colloidal silicon, and then scale inhibitors are added to prevent the deposition of dissolved silicon on the membrane surface. The concentrated brine after reverse osmosis concentration is treated by silicon-removing agents for adsorption and precipitation to remove silicon. Coagulation and precipitation can remove most of the colloidal silicon, and the remaining colloidal silicon will slowly deposit on the membrane surface to form an adhesion layer, which is difficult to clean. The scale inhibitor method requires adding chemical agents to the water use system to prevent the precipitation of silicon compounds from the aqueous solution containing supersaturated silicon, and it cannot remove dissolved silicon at the source. Moreover, after reverse osmosis concentration, the TDS (total dissolved solids) increases. Then, silicon-removing agents are used to remove dissolved silicon, and due to the influence of the salt effect, there are problems such as a large dosage of the added agent and a slow sedimentation rate of the adsorbed silicon precipitate.

[0004] Chinese Patent Application CN108751523A discloses a method and system for removing hardness and silicon and concentrating high-salt wastewater. First, lime, soda ash, and magnesium oxide are added to the high-salt wastewater for silicon removal treatment, then it is filtered through a tubular membrane. After the produced water is adjusted for pH, it passes through a weak acid cation exchange resin to remove hardness, and through a decarbonator to remove alkalinity. Then, after adjusting the pH again, the produced water is concentrated by reverse osmosis; however, this technical solution has problems such as a large dosage of the added agent and an unsatisfactory silicon removal effect under high-salt conditions.

[0005] Chinese Patent Application CN109734216A discloses a treatment system and process for removing hardness, silicon, and turbidity from high-salt wastewater. The chemical coagulation and precipitation process is coupled with the membrane filtration process. Through chemical reactions, silicon hardness is precipitated to form particulate matter, and then it is sent to a membrane mud-water separation device for filtration and removal; however, in the actual project application process, there are problems such as difficult sedimentation of particulate matter, high water content, and large land occupation for sludge concentration treatment. The suspended particulate matter enters the subsequent membrane device, causing membrane blockage, frequent cleaning, and a rapid decline in the treatment capacity.

[0006] Chinese Patent Application CN108059269A discloses a system and process for removing silica and hardness from industrial wastewater, which uses a conditioning process, a reaction process, a flocculation process and a precipitation process to remove hardness and silica. However, among the added chemicals, there is no chemical for removing hardness, and the pH has opposite effects during the processes of removing hardness and silicon, thus the problem of removing hardness cannot be solved.

[0007] It can be seen that in the process of removing silicon in the above patent application, the forms of silicon existing in the wastewater and the transformation of silicon forms in different treatment process sections are not considered. The chemical coagulation and precipitation method is directly adopted without considering the influence of salt effect on silicon removal, resulting in an unsatisfactory silicon removal effect. In the actual engineering application process, there are problems such as long precipitation time and small precipitation density of chemical silicon removal, leading to the phenomenon of pond turnover.

[0008] In view of this, it is necessary to explore a system and method for efficiently removing silicon from mine concentrated brine. Summary of the Invention

[0009] The purpose of the present invention is to solve the problems in actual engineering, such as large dosage of chemicals for silicon removal, slow silicon sedimentation rate, and poor silicon removal effect under high-salt conditions, and to provide a system and method for efficiently removing silicon from mine concentrated brine.

[0010] To achieve the above purpose, the technical solution provided by the present invention is as follows:

[0011] An aggregating agent, characterized in that: its active ingredient is an inorganic mineral that has been pickled and positively charged modified in sequence; the particle size is 1 - 10 mm, the density is 2.0 - 6.0 g / cm 3 , and the porosity is 20 - 80%;

[0012] The inorganic mineral is a natural mineral or solid waste discharged from coal chemical industry, coal mine and power plant, such as high-density substances like gasification furnace slag, coal gangue, carbide slag, attapulgite, fly ash, etc.

[0013] The preparation method of the above aggregating agent is characterized by including the following steps:

[0014] 1) Pretreatment, aiming to disperse the inorganic mineral

[0015] The inorganic mineral is evenly spread out and dried in a muffle furnace, and the dried inorganic mineral is taken out and formulated into an inorganic mineral suspension with a mass fraction of 10 - 50%;

[0016] A dispersant (such as sodium hexametaphosphate) is added to the inorganic mineral suspension and stirred at room temperature for 20 - 60 min; wherein, the mass ratio of the dispersant to the inorganic mineral is 0.1 - 0.6∶1;

[0017] Centrifuge and wash the stirred inorganic mineral suspension to remove the dispersant, and dry it to obtain the pretreated inorganic minerals for standby;

[0018] 2) Pickling

[0019] Prepare the pretreated inorganic minerals into a suspension with a mass fraction of 4-6% with water, and then add hydrochloric acid to the suspension (using hydrochloric acid for acidification here is safer), to form a suspension containing 0.01-1 mol / L of hydrochloric acid, stir at 55-65 °C for 1.5-2.5 h, and then wash to neutrality to obtain the pickled suspension;

[0020] 3) Positive charge modification

[0021] Under stirring conditions, slowly add a silane coupling agent solution with a molar concentration of 0.8-1.2 mol / L (such as: amino silane solution) to the suspension obtained in step 2), and stir at room temperature for 1.5-2.5 h to obtain a mixed suspension;

[0022] 4) Post-treatment

[0023] Dry the mixed suspension obtained in step 3) by spray drying to obtain the flocculant.

[0024] A system for efficiently removing silicon from mine brine is characterized in that it includes a heterogeneous membrane device, a first-stage reverse osmosis device, a hardness and silicon removal integrated device, an ion exchange device, a second-stage reverse osmosis device, an electroseparation and concentration device, a filtration device, a silicon removal rapid sedimentation device, an evaporation and crystallization device, a first reuse water tank and a second reuse water tank;

[0025] Among them, the heterogeneous membrane device is used to remove impurities in the mine brine, and the impurities are a general term for suspended matter, bacteria, colloidal silicon, etc.;

[0026] The first-stage reverse osmosis device removes salt ions from the water produced by the heterogeneous membrane device to form product water and concentrated water. The product water enters the first reuse water tank for reuse, and the concentrated water enters the hardness and silicon removal integrated device;

[0027] The hardness and silicon removal integrated device uses chemical reactions of reagents, hardness removal precipitation adsorption, and agglomeration adsorption rapid precipitation to remove dissolved silicon and hardness in the concentrated water of the first-stage reverse osmosis device;

[0028] The ion exchange device is used to remove residual hardness and residual polyvalent cations in the water produced by the hardness and silicon removal integrated device, such as: iron ions, manganese ions, etc.;

[0029] The second-stage reverse osmosis device removes salt ions from the water produced by the ion exchange device to form product water and concentrated water. The product water enters the second reuse water tank for reuse, and the concentrated water enters the electroseparation and concentration device;

[0030] The electroseparation and concentration device is used to separate salt ions and soluble silicon in the concentrated water of the second-stage reverse osmosis device to form product water and concentrated water. The concentrated water (i.e., the part of the water containing salt ions) enters the evaporation and crystallization device, and the product water enters the filtration device to remove the saturated precipitated colloidal silicon and then enters the silicon removal rapid sedimentation device to rapidly precipitate and remove the dissolved silicon through agglomeration and adsorption. The generated sludge is refluxed to the hardness and silicon removal integrated device through charge adsorption and network capture to remove the dissolved silicon, and the generated product water (here, the product water after silicon removal, containing calcium and magnesium ion hardness, is refluxed to the ion exchange device for further hardness removal) is refluxed to the ion exchange device;

[0031] The flocculant used in the hardness and silicon removal integrated device and the silicon removal rapid sedimentation device is the above-mentioned flocculant.

[0032] It can be seen that the product water treated by the entire system is the product water of the first-stage reverse osmosis device and the second-stage reverse osmosis device.

[0033] Furthermore, the heterogeneous membrane device is microfiltration or ultrafiltration level filtration, including a feed pump, a membrane core, a backwash pump, a cleaning pump, and a cleaning water tank;

[0034] The membrane core uses a heterogeneous membrane, with a non-woven fabric layer at the bottom and a flexible polymer material layer at the surface. The surface structure is a conical structure, with a smaller pore size near the surface and a larger pore size near the bottom. When the membrane flux decreases, backwashing can be used to restore the membrane flux. Compared with the existing microfiltration or ultrafiltration membranes, it has the advantages of convenient cleaning, a soft surface, rapid separation of blockages from the membrane, and a small decline in membrane flux. The performance requirements of the membrane core are: the product water recovery rate is 80 - 99%, the operating pressure is 0.01 - 10 bar, the product water turbidity is less than 0.01 NTU, and the removal rate of colloidal silicon is over 90%.

[0035] Furthermore, the first-stage reverse osmosis device includes a feed pump, a high-pressure pump, a reverse osmosis membrane core, a cleaning pump, a chemical cleaning pump, and a cleaning water tank;

[0036] The reverse osmosis membrane core uses an atmospheric or high-pressure reverse osmosis membrane, and its performance requirements are that the product water recovery rate is 50% - 90%, the operating pressure is 1 - 50 bar, and the product water TDS is less than 100 mg / L.

[0037] Furthermore, the hardness and silicon removal integrated device has both hardness and silicon removal functions according to the influent water quality, and mainly includes a first reaction tank, a second reaction tank, a sedimentation area, and a separation area;

[0038] Dosing pumps and agitators are installed in both the first reaction tank and the second reaction tank; a sludge thickening tank and a membrane filtration device (this membrane filtration device is used for mud-water separation in the separation area) are installed in the separation area; the second reaction tank and the separation area are connected by a sludge circulation reflux pump to reflux the sludge in the separation area to the second reaction tank;

[0039] The raw water first passes through the first reaction tank for pH adjustment (pH controlled at 8 - 10) and precipitation reaction with sodium hydroxide or calcium hydroxide; then it enters the second reaction tank, and the dosing pump sequentially adds sodium carbonate, magnesium oxide or magnesium chloride, and the aggregating agent. First, calcium carbonate and magnesium hydroxide precipitates are generated, then dissolved silicon adsorbs on the surface of magnesium hydroxide, and the magnesium hydroxide precipitate adsorbed with silicon and the calcium carbonate precipitate adsorb on the surface of the aggregating agent and quickly precipitate to the bottom of the tank. A small amount of floating particles are removed by filtration through a membrane filtration device (a vacuum - negative pressure non - homogeneous membrane).

[0040] Among them, the mass ratio of magnesium oxide or magnesium chloride to dissolved silicon added is 0.5 - 1.5∶1, and the dosing amount of the aggregating agent is 1 - 5 mg / L; the treatment effect of this device: the hardness removal rate is 50 - 90%, and the silicon removal rate is above 80%; throughout the process, there is no need to add coagulants, flocculants, and sodium aluminate for silicon removal agents, reducing the pollution to the subsequent reverse osmosis membrane system.

[0041] Furthermore, the ion - exchange device includes a feed water pump, a regeneration water pump, a resin tank, a backwash pump, and a regeneration chemical tank; among them, strongly acidic, weakly acidic, or chelating cation - exchange resins are used in the resin tank. The resin effluent effect of this device is: the hardness removal rate is above 99%, the hardness of the produced water is less than 1 mg / L, and the removal rate of multivalent cations reaches above 90%, preventing the deposition and pollution of multivalent ions on the surface of the subsequent reverse osmosis membrane.

[0042] Furthermore, the second - stage reverse osmosis device includes a feed water pump, a reverse osmosis membrane element, a cleaning water pump, a chemical cleaning water pump, and a cleaning water tank; among them, a high - pressure membrane is used for the reverse osmosis membrane element, and its performance requirements are: the water production recovery rate is 50 - 90%, and the operating pressure is 5 - 100 bar.

[0043] Furthermore, the electro - separation and concentration device includes electrodes, electrode plates, plate separation partitions, and anion and cation exchange membranes; this device functions through positive and negative electrodes and ion - exchange membranes. Due to the difference in the migration of anions, cations, and dissolved silicon (orthosilicic acid, metasilicic acid, molecular - state silicon dioxide) under the action of an electric field, the function of diluting salt ions and concentrating silicon in the produced water is realized. The TDS in the produced water is 1000 - 20000 mg / L, the silicon in the produced water is above 90% of the influent, and the silicon in the concentrated water is below 10% of the influent. The electro - separation and concentration device is a technology combining electro - deionization, electrodialysis, capacitive deionization technology, continuous electrodeionization technology with anion and cation exchange membranes.

[0044] The filtration device includes a feed water pump, a filtration membrane element, a membrane shell, a backwash water pump, and a backwash water tank. It is a multi - medium, self - cleaning, micro - filtration or ultra - filtration device. The filtration device removes the colloidal silicon that has precipitated saturated after concentration in the raw water, and the remaining dissolved silicon enters the subsequent rapid silicon - removal sedimentation device.

[0045] The silicon removal and rapid sedimentation device includes a first reaction tank, a second reaction tank, a chemical agent dosing tank, a chemical agent dosing pump, a flocculant dosing tank, a flocculant dosing pump, a membrane filtration device, a vacuum pump, a sludge temporary storage area, and a sludge reflux pump. Among them, magnesium oxide or magnesium chloride and a flocculant are sequentially added to the first reaction tank. The mass ratio of magnesium oxide or magnesium chloride to dissolved silicon added is 0.5 - 2:1, and the flocculant dosing amount is 1 - 10 mg / L. The second reaction tank consists of a sedimentation area and a vacuum extraction micro-negative pressure heterogeneous membrane filtration component. The sedimented sludge is refluxed into the front-end hardness and silicon removal integrated device. The turbidity of the produced water is 0.01 NTU, and the silicon removal rate is over 80%. The produced water and the produced water of the hardness and silicon removal integrated device are sent to the ion exchange device together to remove hardness for cyclic treatment.

[0046] The evaporation and crystallization device is used to evaporate and crystallize the concentrated water in the electro-separation and concentration device to crystallize out salts, and recover the water resources in the wastewater to the greatest extent. The evaporation and crystallization device is MVR evaporation and crystallization, single-effect, double-effect, or multi-effect evaporation and crystallization.

[0047] A method for efficiently removing silicon from mine concentrated brine using the above system is characterized in that it includes the following steps:

[0048] S1. The mine concentrated brine with the pH adjusted to less than 7 enters the heterogeneous membrane device, and impurities in the mine water (such as insoluble colloidal silicon in water, silicon adsorbed on the particle surface, etc.) are removed through the heterogeneous membrane. The produced water enters the first-stage reverse osmosis device.

[0049] S2. After the produced water of the heterogeneous membrane device is concentrated by the first-stage reverse osmosis device, the produced water of the first-stage reverse osmosis device enters the first reuse water tank for reuse again, and the concentrated water of the first-stage reverse osmosis device enters the hardness and silicon removal integrated device for further treatment.

[0050] S3. The concentrated water of the first-stage reverse osmosis device enters the hardness and silicon removal integrated device, and the dissolved silicon and hardness in the concentrated water of the first-stage reverse osmosis are rapidly removed through chemical agent chemical reactions, hardening precipitation adsorption, and flocculation adsorption precipitation. The produced water of the hardness and silicon removal integrated device enters the ion exchange device.

[0051] S4. The produced water of the hardness and silicon removal integrated device further removes the hardness in the water through ion exchange to ensure the stable operation of the subsequent membrane and evaporation and crystallization. The produced water of the ion exchange device enters the second-stage reverse osmosis device.

[0052] S5. The produced water of the ion exchange device is concentrated by the second-stage reverse osmosis device. The produced water of the second-stage reverse osmosis device enters the second reuse water tank for reuse again, and the concentrated water of the second-stage reverse osmosis device enters the electro-separation and concentration device.

[0053] S6. The concentrated water of the second-stage reverse osmosis device separates the salt ions and silicon through the electro-separation and concentration device. The produced water of the electro-separation and concentration device enters the filtration device, and the concentrated water of the electro-separation and concentration device enters the evaporation and crystallization device to crystallize and produce salts for recycling.

[0054] S7. The water produced by the electroseparation and concentration device is passed through a filtration device to remove the colloidal silicon that has precipitated out after concentration, and the water enters the rapid silicon removal and sedimentation device.

[0055] S8. The water produced by the filtration device undergoes chemical reaction adsorption and agglomeration adsorption of chemicals to rapidly precipitate and remove dissolved silicon. The settled sludge is refluxed and enters the integrated hardness and silicon removal device through charge adsorption and network capture to enhance the adsorption and capture effect of silicon removal precipitation. The water produced enters the ion exchange device to remove hardness and then enters the secondary reverse osmosis device for cyclic treatment.

[0056] In summary, the process of removing silicon using the above system for efficiently removing silicon from mine brine is as follows: First, the colloidal silicon in the mine brine with pH < 7 is removed through the heterogeneous membrane device. After the water produced is concentrated by the primary reverse osmosis, the concentrated water enters the integrated hardness and silicon removal device, where the dissolved silicon and hardness in the primary reverse osmosis concentrated water are removed through chemical reaction of chemicals, hardness removal precipitation adsorption, and agglomeration adsorption rapid precipitation. The water produced is filtered through a vacuum-assisted micro-negative pressure heterogeneous membrane to remove a small amount of non-settled particulate matter. After the water produced is further dehardened through ion exchange, it enters the secondary reverse osmosis for concentration. The concentrated water enters the electroseparation and concentration device to separate the salt ions and soluble silicon in the concentrated water. The separated concentrated water enters the evaporation crystallization to produce salt, and the separated water produced enters the filtration device to remove the precipitated colloidal silicon that has reached saturation, then enters the rapid silicon removal and sedimentation device, where the dissolved silicon is removed through agglomeration adsorption rapid precipitation. The generated sludge is refluxed into the integrated hardness and silicon removal device to enhance the adsorption and capture effect of silicon removal and hardness removal precipitation. The water produced enters the ion exchange resin to remove hardness and then enters the secondary reverse osmosis device for cyclic treatment.

[0057] Principle of the present invention:

[0058] The present invention combines a membrane filtration process (corresponding to the heterogeneous membrane device), a chemical adsorption precipitation + agglomeration adsorption rapid precipitation technology (corresponding to the integrated hardness and silicon removal device), a salt concentration and silicon separation technology (corresponding to the electroseparation and concentration device + filtration device), and a sludge reflux capture silicon removal technology (corresponding to the design of refluxing the sludge from the rapid silicon removal and sedimentation device to the integrated hardness and silicon removal device). Through deep filtration of the heterogeneous membrane, the colloidal silicon in the water is removed. Through hardness precipitation and sludge, the dissolved silicon in the water is adsorbed and precipitated for removal. The salt concentration and separation technology realizes the effective separation of silicon and salt ions in the water, achieving the effect of concentrating silicon in the water produced, and laying a foundation for reducing the interference of the salt effect in the subsequent agglomeration adsorption rapid precipitation technology for silicon removal.

[0059] In the overall process, a strategy of mutual conversion between two forms of silicon (the (1) and (2) forms in the background technology) is utilized to remove total silicon. The specific mechanism is as follows: First, the pH of the mine brine is adjusted to < 7, causing some dissolved silicon to transform into colloidal silicon, which enters the heterogeneous membrane device for removal; subsequently, the pH in the integrated hardness and silicon removal device is controlled at 8 - 10, enabling magnesium hydroxide to adsorb dissolved silicon and colloidal silicon, and then adsorbing on the surface of the flocculant to remove total silicon; the pH of the water produced by the electro-separation and concentration device is < 7, and some dissolved silicon will transform into colloidal silicon, which enters the subsequent filtration device for removal; then it enters the silicon removal rapid sedimentation device with a pH of 8 - 10. Similarly, magnesium hydroxide adsorbs dissolved silicon and colloidal silicon, and then adsorbs on the surface of the flocculant to remove total silicon; thus, the entire process achieves the comprehensive removal of colloidal silicon and dissolved silicon.

[0060] Advantages of the present invention:

[0061] 1. In view of the existing situation where both colloidal silicon and dissolved silicon exist in mine water, the silicon removal system of the present invention adopts the "heterogeneous membrane filtration technology and filtration technology" to remove colloidal silicon in two stages, reducing the load of subsequent chemical adsorption silicon removal and the risk of reverse osmosis membrane fouling. It adopts the "integrated hardness and silicon removal device + silicon removal rapid sedimentation device + salt concentration and silicon separation technology" to remove dissolved silicon, and different removal methods are adopted for different forms of silicon, having the advantages of high removal efficiency and wide application range.

[0062] 2. Aiming at the problems of low silicon removal rate and large chemical agent dosage under high-salt conditions in the existing zero-discharge system for mine water, the present invention innovatively adopts the electro-separation and concentration technology to separate salt ions and silicon in the high-salt water of the second-stage reverse osmosis. The produced water has the characteristics of low salinity and high silicon, and the concentrated water has the characteristics of high salinity and low silicon. The high-salt and low-silicon concentrated water enters the subsequent evaporation and crystallization process, reducing the risk of silicon scaling in evaporation and crystallization and ensuring the stable operation of the evaporation and crystallization process.

[0063] 3. In the present invention, the integrated hard silicon removal device and the rapid silicon sedimentation device adopt the technologies of chemical adsorption and agglomeration adsorption with agents to rapidly precipitate dissolved silicon, without adding coagulants and flocculants, reducing the pollution risk of PAM and PAC in the subsequent reverse osmosis membrane system. The magnesium hydroxide generated by hard removal can be used for silicon removal, reducing the dosage of magnesium oxide / magnesium chloride. It has the characteristics of high removal efficiency, low dosage of agents, and fast sedimentation speed of precipitates. Due to the fast sedimentation speed of precipitates, the required sedimentation area is reduced, the floor area of the entire device is decreased, and the investment cost is reduced. At the same time, the sludge of the rapid silicon sedimentation device is refluxed into the integrated hard silicon removal device to strengthen the adsorption and capture effect of silicon precipitation, reducing the dosage of agents and agglomerants. The secondary reverse osmosis concentrated water undergoes the processes of concentration and filtration by the electro-separation concentration device. Due to the extension of time, the added scale inhibitor becomes ineffective, reducing the impact of the scale inhibitor on the silicon removal efficiency. The adopted agglomerant is an inorganic mineral (natural mineral or solid waste discharged from coal chemical industry, coal mine, and power plant) that has been pickled and positively charged modified in sequence. Its raw materials are originally solid wastes from coal mining, power plants, and coal chemical projects, enabling high-quality resource utilization of solid wastes. The present invention realizes the recycling of solid wastes through the agglomeration technology, reduces the dosage of chemical agents, lowers the silicon removal cost, and achieves rapid and efficient silicon removal.

[0064] 4. The electro-separation concentration device of the present invention not only effectively separates salt ions from silicon, but also concentrates the secondary reverse osmosis concentrated water, increasing the salt concentration of the feed water to the evaporation crystallization system, reducing the scale of the subsequent evaporation crystallization system, and effectively reducing the investment and operation costs of the entire system.

[0065] 5. The surface structure of the heterogeneous membrane device adopted in the present invention is a conical structure, with a small pore size near the surface and a large pore size near the bottom. When the membrane flux decreases, the membrane flux can be quickly restored by backwashing. Compared with the existing microfiltration or ultrafiltration membranes, it has the advantages of convenient cleaning, a soft surface layer, rapid separation of blockages from the membrane, and small attenuation of membrane flux.

[0066] 6. The present invention adopts multiple coupling methods to optimize the silicon removal process and introduces the designed agglomerant, having the advantages of integrated removal of dissolved silicon and colloidal silicon, reducing the influence of salt effect, with low chemical consumption and high efficiency, and being well compatible with the existing mine water zero-discharge system. It can effectively control the silicon content entering the evaporation crystallization system, reduce the scaling risk of the subsequent evaporation crystallization process, ensure the stable operation of the evaporation crystallization process, and have broad application prospects. Description of the Drawings

[0067] Figure 1 is the system flow chart of the present invention;

[0068] Figure 2 is the silicon removal process flow chart used in Comparative Example 1;

[0069] Wherein: 1 - mine concentrated brine, 2 - heterogeneous membrane device, 3 - first-stage reverse osmosis device, 4 - first reuse water tank, 5 - integrated hardness and silica removal device, 6 - ion exchange device, 7 - second-stage reverse osmosis device, 8 - second reuse water tank, 9 - electroseparation and concentration device, 10 - evaporation and crystallization device, 11 - filtration device, 12 - rapid silica removal sedimentation device. Detailed implementation mode

[0070] The following further describes the content of the present invention in detail in conjunction with the accompanying drawings and specific embodiments:

[0071] A system for efficiently removing silica from mine water, as Figure 1 shown, includes a heterogeneous membrane device, a first-stage reverse osmosis device, an integrated hardness and silica removal device, an ion exchange device, a second-stage reverse osmosis device, an electroseparation and concentration device, a filtration device, a rapid silica removal sedimentation device, an evaporation and crystallization device, a first reuse water tank, and a second reuse water tank.

[0072] The heterogeneous membrane device is used to remove impurities such as suspended solids, bacteria, and colloidal silica in mine concentrated brine (first adjust the pH of the mine concentrated brine to less than 7); it is a microfiltration or ultrafiltration level filtration, including a feed water pump, a membrane core, a backwash water pump, a cleaning water pump, and a cleaning water tank; among them, the membrane core uses a heterogeneous membrane, with a non-woven fabric at the bottom and a flexible polymer material on the surface, and the surface structure is a conical structure, with a smaller pore size near the surface and a larger pore size near the bottom. The performance requirements of this membrane core are that the water production recovery rate is 80 - 99%, the operating pressure is 0.01 - 10 bar, the water production turbidity is less than 0.01 NTU, and the removal rate of colloidal silica is more than 90%;

[0073] The first-stage reverse osmosis device removes salt ions in water through a reverse osmosis membrane to make the product water reusable, including a feed water pump, a high-pressure pump, a reverse osmosis membrane core, a cleaning water pump, a chemical cleaning water pump, and a cleaning water tank; among them, the reverse osmosis membrane core uses an atmospheric or high-pressure reverse osmosis membrane, and the performance requirements are that the water production recovery rate is 50 - 90%, the operating pressure is 1 - 50 bar, and the water production TDS is less than 100 mg / L.

[0074] The integrated hardness and silica removal device removes calcium and magnesium ions in water according to the water quality situation by using the double-alkali method or adding lime method, etc., adds magnesium oxide and magnesium chloride to remove silica, and adds a flocculant to accelerate the sedimentation rate of calcium and magnesium precipitates and the magnesium hydroxide precipitate adsorbing silica. This device includes a first reaction tank, a second reaction tank, a sedimentation area, and a separation area; dosing pumps and agitators are installed in both the first reaction tank and the second reaction tank; a sludge thickening tank and a membrane filtration device are installed in the separation area; the second reaction tank and the separation area are connected by a sludge circulation return pump to return the sludge in the separation area to the second reaction tank.

[0075] The ion exchange device is used to further remove the residual hardness and residual polyvalent cations in the water produced by the integrated hardness and silica removal device; it includes a feed water pump, a regeneration water pump, a resin tank, a backwash pump and a regeneration chemical tank; among them, strong acid, weak acid or chelating cation exchange resin is used in the resin tank, and the resin effluent effect of this device is: the hardness removal rate is above 99%, the produced water hardness is less than 1 mg / L, the polyvalent cation removal rate reaches above 90%, preventing the deposition and pollution of polyvalent ions on the surface of the subsequent reverse osmosis membrane.

[0076] The secondary reverse osmosis device removes the salt ions in the water produced by the ion exchange device through the permeation membrane, so that the product water can be recycled; it includes a feed water pump, a reverse osmosis membrane element, a cleaning water pump, a chemical cleaning water pump and a cleaning water tank; among them, the reverse osmosis membrane element uses a high-pressure membrane, and its performance requirements are a recovery rate of 50 - 90% and an operating pressure of 5 - 100 bar.

[0077] The electro-separation and concentration device separates and concentrates the cations and anions in the water through the driving of the electrode electric field, reducing the salt ion content in the treated water, while the migration amount of dissolved silica and colloidal silica in the electric field is small, and it flows out with the produced water. The electro-separation and concentration device includes electrodes, electrode plates, plate separation partitions and cation and anion exchange membranes.

[0078] The filtration device is a self-cleaning, multi-media, microfiltration or ultrafiltration device. The filtration device removes the colloidal silica that has saturated and precipitated after concentration in the incoming water, and the remaining dissolved silica enters the subsequent rapid silica removal sedimentation device. It includes a feed water pump, a filtration membrane element, a membrane shell, a backwash water pump and a backwash water tank.

[0079] The rapid silica removal sedimentation device includes reaction tank 1, reaction tank 2, chemical dosing tank, chemical dosing pump, flocculant dosing tank, flocculant dosing pump, membrane filtration device, vacuum pump, sludge storage and sludge reflux pump; magnesium oxide or magnesium chloride and flocculant are added in reaction tank 1; reaction tank 2 consists of a sedimentation area and a vacuum-extracted slightly negative pressure non-homogeneous membrane filtration device, and the settled sludge flows back into the front-end integrated hardness and silica removal device to remove dissolved silica, and the produced water generated (here, the produced water after silica removal, containing calcium and magnesium ion hardness, flows back to the ion exchange device for further hardness removal) flows back to the ion exchange device;

[0080] The evaporation and crystallization device is used to evaporate and crystallize the salt in the concentrated water of the electro-separation and concentration device, and recover the water resources in the wastewater to the greatest extent. The evaporation and crystallization device is MVR evaporation and crystallization, single-effect, double-effect or multi-effect evaporation and crystallization.

[0081] Each of the above devices can be obtained through commercial channels according to performance requirements. Among them, the flocculant used in the integrated hardness and silica removal device and the rapid silica removal sedimentation device is an inorganic mineral that has been pickled and positively charged modified in sequence; the particle size is 1 - 10 mm, and the density is 2.0 - 6.0 g / cm 3, with a porosity of 20 - 80%; the inorganic minerals are natural minerals or solid waste discharged from coal chemical industry, coal mines and power plants, such as high-density substances like gasification slag, coal gangue, carbide slag, attapulgite, fly ash, etc. In this embodiment, it can be prepared by the following method:

[0082] 1) Disperse and pre-treat the gasification slag

[0083] Spread the gasification slag evenly and put it into a crucible, then put the crucible into a muffle furnace and dry it at 100°C for 30 min; weigh the dried gasification slag and prepare a gasification slag suspension with a mass fraction of 40%; add sodium hexametaphosphate to it (where the mass ratio of sodium hexametaphosphate to gasification slag is 0.1∶1) and stir at room temperature for 1 h, then centrifuge and wash to clean the contained sodium hexametaphosphate, and dry it in an oven at 100°C to obtain the pre-treated gasification slag for standby;

[0084] 2) Acid pickling

[0085] Take 100 g of the gasification slag pre-treated in step 1), prepare a suspension with a mass fraction of 5%, then add hydrochloric acid to it to form a suspension containing 1 mol / L hydrochloric acid, stir at 60°C for 2 h, and then wash it with deionized water until neutral to obtain the acid-pickled suspension;

[0086] 3) Positive charge modification

[0087] Under stirring conditions, slowly add an amino silane solution with a molar concentration of 1 mol / L to the suspension obtained in step 2), and stir at room temperature for 2 h to obtain a mixed suspension;

[0088] 4) Post-treatment

[0089] Carry out spray drying on the mixed suspension obtained in step 3) under the conditions of 170°C and 0.15 Mpa to obtain the flocculant.

[0090] Of course, the flocculants prepared within the scope of the foregoing preparation process can all be applied to the subsequent efficient removal of silicon in mine water.

[0091] The present invention also provides a method for efficiently removing silicon in mine water, which is used for the method of efficiently removing silicon in the above-mentioned mine water. The specific steps are as follows:

[0092] S1. Mine concentrated brine with a pH adjusted to less than 7 enters the heterogeneous membrane device, and impurities in the mine water (such as insoluble colloidal silicon in water, silicon adsorbed on the particle surface, etc.) are removed through the heterogeneous membrane, and the produced water enters the first-stage reverse osmosis device;

[0093] S2. After the water produced by the heterogeneous membrane device is concentrated by the first-stage reverse osmosis device, the water produced by the first-stage reverse osmosis device enters the first reuse water tank, and the concentrated water of the first-stage reverse osmosis device enters the integrated hardness and silica removal device for further treatment;

[0094] S3. The concentrated water of the first-stage reverse osmosis device enters the integrated hardness and silica removal device, and the dissolved silica and hardness in the first-stage reverse osmosis concentrated water are quickly removed through chemical reactions of reagents, hardness removal precipitation adsorption, and agglomeration adsorption. The water produced by the integrated hardness and silica removal device enters the ion exchange device;

[0095] S4. The water produced by the integrated hardness and silica removal device further removes the hardness in the water through ion exchange to ensure the stable operation of the subsequent membranes and evaporation crystallization. The water produced by the ion exchange device enters the second-stage reverse osmosis device;

[0096] S5. The hardness removal water produced by the ion exchange device is concentrated by the second-stage reverse osmosis device. The water produced by the second-stage reverse osmosis device enters the second reuse water tank, and the concentrated water of the second-stage reverse osmosis device enters the electro-separation and concentration device;

[0097] S6. The concentrated water of the second-stage reverse osmosis device separates the salt ions and silica through the electro-separation and concentration device. The water produced by the electro-separation and concentration device enters the filtration device, and the concentrated water of the electro-separation and concentration device enters the evaporation crystallization device to crystallize and produce salt for recycling;

[0098] S7. The water produced by the electro-separation and concentration device removes the colloidal silica precipitated after concentration through the filtration device, and the water (including the remaining dissolved silica) enters the rapid silica removal sedimentation device; S8. The water produced by the filtration device removes the dissolved silica through chemical reactions of reagents, adsorption, and agglomeration adsorption for rapid precipitation. The settled sludge flows back through charge adsorption and network capture and returns to the integrated hardness and silica removal device to enhance the adsorption and capture effect of silica removal precipitation. The produced water and the water produced by the integrated hardness and silica removal device are sent to the ion exchange device for hardness removal and then enter the second-stage reverse osmosis device for cyclic treatment.

[0099] Example 1

[0100] Mine brine with 3068 mg / L of dissolved solids, 460 mg / L of total hardness, and 28.6 mg / L of silicon (20.6 mg / L of reactive silicon and 8.0 mg / L of colloidal silicon) is fed into a heterogeneous membrane device. The suspended solids in the mine water (including insoluble colloidal silicon in water, silicon adsorbed on the particle surface, etc.) are removed through the heterogeneous membrane. The silicon content in the water produced by the heterogeneous membrane is 21.3 mg / L. The produced water enters a first-stage reverse osmosis device, where it is concentrated 4 times by the reverse osmosis device. The produced water enters the first reuse water tank, and the concentrated water enters a subsequent hardness and silicon removal integrated device; 80 mg / L of magnesium oxide is added to adsorb dissolved silicon, and 3.5 mg / L of modified coal gangue is added as a flocculant to adsorb the precipitate of magnesium hydroxide adsorbing silicon, so as to efficiently remove the hardness and silicon in the water. The silicon content in the produced water is 15.1 mg / L, and the hardness is 51 mg / L; the produced water from the hardness and silicon removal integrated device enters an ion exchange device, where the hardness in the water is further removed through ion exchange. The hardness of the produced water is 0.8 mg / L; the produced water after hardness removal by ion exchange resin enters a second-stage reverse osmosis device, where it is concentrated 5 times by the reverse osmosis device. The produced water enters the second reuse water tank, and the concentrated water enters a subsequent electroseparation and concentration device; the concentrated water from the second-stage reverse osmosis is separated into salt ions and silicon by the electroseparation and concentration device. The concentrated water with a TDS of 70560 mg / L and a silicon content of 5.2 mg / L enters a subsequent evaporation and crystallization device to crystallize and produce salt. The produced water with a TDS of 15260 mg / L and a silicon content of 230 mg / L enters a heterogeneous membrane filtration device to remove 80 mg / L of colloidal silicon that precipitates oversaturated after the scale inhibitor fails. The silicon content in the produced water is 150 mg / L and enters a rapid silicon removal sedimentation device. 140 mg / L of magnesium oxide is added to adsorb dissolved silicon, and 6 mg / L of modified coal gangue is added as a flocculant to adsorb the precipitate of magnesium hydroxide adsorbing silicon, and rapid sedimentation is carried out. The sludge with a solid content of 3% in the sedimentation is refluxed to the front-end hardness and silicon removal integrated device to strengthen the adsorption and capture effect of silicon precipitation. The produced water with a silicon content of 20 mg / L is fed into an ion exchange device to remove hardness for cyclic treatment.

[0101] Comparative Example 1

[0102] The quality of the mine brine used in this comparative example is the same as that in Example 1, and a silicon removal process is adopted as a whole. Figure 2 as shown:

[0103] Mine brine with 3068 mg / L of dissolved solids, 460 mg / L of total hardness, and 28.6 mg / L of silicon (20.6 mg / L of reactive silicon and 8.0 mg / L of colloidal silicon) is fed into the ultrafiltration membrane device. The suspended solids in the mine water (including insoluble colloidal silicon in water, silicon adsorbed on the particle surface, etc.) are removed through the ultrafiltration membrane. The dissolved silicon in the ultrafiltration membrane product water is 21.3 mg / L. The product water enters the first-stage reverse osmosis device and is concentrated 4 times by the reverse osmosis device. The product water enters the first reuse water tank, and the concentrated water enters the subsequent high-density sedimentation tank; 40 mg / L of sodium hydroxide is added to adjust the pH to 11.5, 800 mg / L of calcium hydroxide is added, and 85 mg / L of magnesium oxide is added to remove the hardness in the water. The hardness of the product water is 61 mg / L, and the silicon is 45 mg / L; the product water from the high-density sedimentation tank enters the ion exchange device, and the hardness in the water is further removed through the ion exchange device. The hardness of the product water is 2 mg / L; the product water from the ion exchange resin for hardness removal enters the multi-stage reverse osmosis device and is concentrated 6 times by the reverse osmosis device. The concentrated water enters the subsequent silicon removal sedimentation tank; 20 mg / L of sodium hydroxide is added in the silicon removal sedimentation tank to adjust the pH to 9.5, and 1525 mg / L of sodium aluminate is added to remove the dissolved silicon. The concentrated water with a TDS of 61123 mg / L and a silicon content of 28.5 mg / L enters the subsequent evaporation crystallization device to crystallize and produce salt, and the product water with a TDS of 523 mg / L and a silicon content of 3 mg / L enters the reuse water tank for reuse.

[0104] It can be seen that under the same influent water quality conditions, the concentrated water finally entering the evaporation crystallization in Example 1 has a TDS of 70560 mg / L and a silicon content of 5.2 mg / L, reducing the scaling risk of the subsequent evaporation crystallization device; in Comparative Example 1, the concentrated water finally entering the evaporation crystallization has a TDS of 61123 mg / L and a silicon content of 28.5 mg / L, and the scaling risk of the subsequent evaporation crystallization device is very high.

[0105] Example 2

[0106] Mine brine with a dissolved solids content of 2982 mg / L, a total hardness of 503 mg / L, and a silicon content of 29.5 mg / L (21.8 mg / L of reactive silicon and 7.7 mg / L of colloidal silicon) is fed into a heterogeneous membrane device. The suspended solids in the mine water are removed through the heterogeneous membrane, including insoluble colloidal silicon in the water, silicon adsorbed on the particle surface, etc. The silicon content in the water produced by the heterogeneous membrane is 22.5 mg / L. The produced water enters a primary reverse osmosis device, where it is concentrated 4 times through the reverse osmosis device. The produced water enters the first reuse water tank, and the concentrated water enters the subsequent integrated hardness and silicon removal device; 86 mg / L of magnesium oxide is added to adsorb dissolved silicon, and 3.8 mg / L of modified coal gangue aggregating agent is added to adsorb the precipitate of magnesium hydroxide adsorbed silicon, effectively removing the hardness and silicon in the water. The silicon content in the produced water is 16.2 mg / L, and the hardness is 62 mg / L; the produced water from the integrated hardness and silicon removal device enters an ion exchange device, where the hardness in the water is further removed through ion exchange. The hardness of the produced water is 1.0 mg / L; the produced water after hardness removal by ion exchange resin enters a secondary reverse osmosis device, where it is concentrated 5 times through the reverse osmosis device. The produced water enters the second reuse water tank, and the concentrated water enters the subsequent electro-separation and concentration device; the concentrated water from the secondary reverse osmosis is separated into salt ions and silicon through the electro-separation and concentration device. The concentrated water with a TDS of 85236 mg / L and a silicon content of 6.3 mg / L enters the subsequent evaporation and crystallization device to produce salt. The produced water with a TDS of 11598 mg / L and a silicon content of 243 mg / L enters a heterogeneous membrane filtration device to remove 93 mg / L of colloidal silicon that precipitates oversaturated after the scale inhibitor fails. The produced water with a silicon content of 147 mg / L enters a rapid silicon removal sedimentation device. 135 mg / L of magnesium oxide is added to adsorb dissolved silicon, and 5.2 mg / L of modified coal gangue aggregating agent is added to adsorb the precipitate of magnesium hydroxide adsorbed silicon, followed by rapid sedimentation. The sludge with a solid content of 3.5% in the sedimentation is refluxed into the front-end integrated hardness and silicon removal device to enhance the adsorption and capture effect of silicon precipitation. The produced water with a silicon content of 18.5 mg / L is sent to an ion exchange device to remove hardness for cyclic treatment.

[0107] Example 3

[0108] Mine brine with a dissolved solids content of 3695 mg / L, a total hardness of 416 mg / L, and silicon content of 27.5 mg / L (20.6 mg / L of reactive silicon and 6.9 mg / L of colloidal silicon) is fed into a heterogeneous membrane device. The suspended solids in the mine water, including insoluble colloidal silicon in the water, silicon adsorbed on the particle surface, etc., are removed through the heterogeneous membrane. The silicon content in the water produced by the heterogeneous membrane is 21.8 mg / L. The produced water enters a primary reverse osmosis device, where it is concentrated by 4 times through the reverse osmosis device. The produced water enters the first reuse water tank, and the concentrated water enters a subsequent integrated hardness and silicon removal device; 79 mg / L of magnesium oxide is added to adsorb dissolved silicon, and 3.3 mg / L of modified coal gangue aggregating agent is added to adsorb the precipitate of magnesium hydroxide adsorbed silicon, so as to efficiently remove the hardness and silicon in the water. The silicon content in the produced water is 14.6 mg / L, and the hardness is 75 mg / L; the produced water from the integrated hardness and silicon removal device enters an ion exchange device, where the hardness in the water is further removed through ion exchange. The hardness of the produced water is 0.6 mg / L; the water produced by the ion exchange resin for hardness removal enters a secondary reverse osmosis device, where it is concentrated by 5 times through the reverse osmosis device. The produced water enters the second reuse water tank, and the concentrated water enters a subsequent electro-separation and concentration device; the concentrated water from the secondary reverse osmosis is separated into salt ions and silicon through the electro-separation and concentration device. The concentrated water with a TDS of 91568 mg / L and a silicon content of 4.9 mg / L enters a subsequent evaporation and crystallization device to crystallize and produce salt. The produced water with a content of 16532 mg / L and a silicon content of 218 mg / L enters a heterogeneous membrane filtration device to remove 73 mg / L of colloidal silicon that precipitates oversaturated after the scale inhibitor fails. The produced water with a silicon content of 145 mg / L enters a rapid silicon removal sedimentation device, where 126 mg / L of magnesium oxide is added to adsorb dissolved silicon, and 5.6 mg / L of modified coal gangue aggregating agent is added to adsorb the precipitate of magnesium hydroxide adsorbed silicon, and rapid sedimentation is carried out. The sludge with a solid content of 4% in the sedimentation is refluxed into the front-end integrated hardness and silicon removal device to strengthen the adsorption and capture effect of silicon precipitation. The produced water with a silicon content of 17.6 mg / L is sent to an ion exchange device to remove hardness for cyclic treatment.

[0109] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. An aggregating agent, characterized in that: Its active ingredient is an inorganic mineral that has been pickled and positively charged modified in sequence; the particle size is 1-10 mm, and the density is 2.0-6.0 g / cm 3 , and the porosity is 20-80%; The inorganic minerals are natural minerals or solid wastes discharged from coal chemical industry, coal mines and power plants.

2. The preparation method of the aggregating agent according to claim 1, characterized in that, It includes the following steps: 1) Pretreatment Evenly spread the inorganic minerals and place them in a muffle furnace for drying. Take out the dried inorganic minerals and prepare an inorganic mineral suspension with a mass fraction of 10 - 50%; Add a dispersant to the inorganic mineral suspension and stir at room temperature for 20 - 60 min; wherein, the mass ratio of the dispersant to the inorganic minerals is 0.1 - 0.6∶1; Centrifuge and wash the stirred inorganic mineral suspension to remove the dispersant, and obtain the pretreated inorganic minerals for standby after drying; 2) Pickling Use water to prepare a suspension with a mass fraction of 4 - 6% of the pretreated inorganic minerals, then add hydrochloric acid to the suspension to form a suspension containing 0.01 - 1 mol / L of hydrochloric acid, stir at 55 - 65 °C for 1.5 - 2.5 h, and then wash to neutrality to obtain the pickled suspension; 3) Positive charge modification Under stirring conditions, slowly add a silane coupling agent solution with a molar concentration of 0.8 - 1.2 mol / L to the suspension obtained in step 2), and stir at room temperature for 1.5 - 2.5 h to obtain a mixed suspension; 4) Post-treatment Use spray drying method to dry the mixed suspension obtained in step 3) to obtain the flocculant.

3. A system for efficiently removing silicon from mine brine, characterized in that: It includes a heterogeneous membrane device, a first-stage reverse osmosis device, a hardness and silicon removal integrated device, an ion exchange device, a second-stage reverse osmosis device, an electro-separation and concentration device, a filtration device, a silicon removal and rapid sedimentation device, an evaporation and crystallization device, a first reuse water tank and a second reuse water tank; Among them, the heterogeneous membrane device is used to remove impurities in the mine concentrated brine; The first-stage reverse osmosis device removes salt ions in the water produced by the heterogeneous membrane device to form product water and concentrated water. The product water enters the first reuse water tank, and the concentrated water enters the hardness and silicon removal integrated device; The hardness and silicon removal integrated device uses pharmaceutical chemical reactions, hardness removal precipitation adsorption and agglomeration adsorption rapid precipitation to remove dissolved silicon and hardness in the concentrated water of the first-stage reverse osmosis device; The ion exchange device is used to remove the residual hardness and residual polyvalent cations in the water produced by the hardness and silicon removal integrated device; The second-stage reverse osmosis device removes salt ions in the water produced by the ion exchange device to form product water and concentrated water. The product water enters the second reuse water tank, and the concentrated water enters the electro-separation and concentration device; The electro-separation and concentration device is used to separate salt ions and soluble silicon in the concentrated water of the second-stage reverse osmosis device to form product water and concentrated water. The concentrated water enters the evaporation and crystallization device. After the product water enters the filtration device to remove the saturated precipitated colloidal silicon, it then enters the silicon removal and rapid sedimentation device to remove dissolved silicon through agglomeration adsorption rapid precipitation. The generated sludge returns to the hardness and silicon removal integrated device through charge adsorption and network capture to remove dissolved silicon, and the generated product water returns to the ion exchange device; The flocculant used in the hardness and silicon removal integrated device and the silicon removal and rapid sedimentation device is the flocculant described in claim 1.

4. The system for efficiently removing silicon from mine concentrated brine according to claim 3, characterized in that: The heterogeneous membrane device is a microfiltration or ultrafiltration level filtration, and includes a feed water pump, a membrane core, a backwash water pump, a cleaning water pump and a cleaning water tank; The membrane core uses a heterogeneous membrane. The bottom layer is non-woven fabric and the surface layer is a flexible polymer material. The surface layer structure is a conical structure, with a smaller pore size near the surface layer and a larger pore size near the bottom layer. Its performance requirements are as follows: The water production recovery rate is 80 - 99%, the operating pressure is 0.01 - 10 bar, the turbidity of the produced water is less than 0.01 NTU, and the removal rate of colloidal silicon is more than 90%.

5. The system for efficiently removing silicon from mine concentrated salt water according to claim 4, characterized in that: The primary reverse osmosis device includes a feed water pump, a high-pressure pump, a reverse osmosis membrane core, a cleaning water pump, a chemical cleaning water pump, and a cleaning water tank; The reverse osmosis membrane core uses an atmospheric or high-pressure reverse osmosis membrane. Its performance requirements are that the water production recovery rate is 50% - 90%, the operating pressure is 1 - 50 bar, and the TDS of the produced water is less than 100 mg / L.

6. The system for efficiently removing silicon from mine concentrated salt water according to claim 5, characterized in that: The hardness and silicon removal integrated device includes a first reaction tank, a second reaction tank, a sedimentation area, and a separation area; Dosing pumps and agitators are provided in both the first reaction tank and the second reaction tank; a sludge thickening tank and a membrane filtration device are provided in the separation area; A sludge circulation return pump is connected between the second reaction tank and the separation area to return the sludge in the separation area to the second reaction tank; The incoming water first passes through the first reaction tank for pH adjustment and precipitation reaction with sodium hydroxide or calcium hydroxide; then it enters the second reaction tank, where sodium carbonate, magnesium oxide or magnesium chloride, and an agglomerant are added in sequence. First, calcium carbonate and magnesium hydroxide precipitates are generated, and then dissolved silicon is adsorbed on the surface of magnesium hydroxide. The magnesium hydroxide precipitate adsorbed with silicon and the calcium carbonate precipitate are adsorbed on the surface of the agglomerant and quickly precipitate to the bottom of the tank body. A small amount of floating particles are removed by filtration through the membrane filtration device; Among them, the mass ratio of magnesium oxide or magnesium chloride to dissolved silicon added is 0.5 - 1.5∶1, and the dosage of the agglomerant is 1 - 5 mg / L.

7. The system for efficiently removing silicon from mine concentrated salt water according to claim 6, characterized in that: The ion exchange device includes a feed water pump, a regeneration water pump, a resin tank, a backwash pump, and a regeneration chemical tank; among them, strong acidic, weakly acidic, or chelating cation exchange resins are used in the resin tank.

8. The system for efficiently removing silicon from mine concentrated salt water according to claim 7, characterized in that: The secondary reverse osmosis device includes a feed water pump, a reverse osmosis membrane core, a cleaning water pump, a chemical cleaning water pump, and a cleaning water tank; The reverse osmosis membrane core uses a high-pressure membrane. Its performance requirements are as follows: The water production recovery rate is 50 - 90%, and the operating pressure is 5 - 100 bar.

9. The system for efficiently removing silicon from mine concentrated salt water according to claim 8, characterized in that: The silicon removal rapid sedimentation device includes a first reaction pool and a second reaction pool. Magnesium oxide or magnesium chloride and an agglomerant are added in sequence in the first reaction pool; the second reaction pool consists of a sedimentation area and a vacuum micro-negative pressure heterogeneous membrane filtration module of a membrane filtration device; the settled sludge is refluxed into the front-end hardness and silicon removal integrated device, and the produced water and the produced water of the hardness and silicon removal integrated device are sent to the ion exchange device together to remove hardness and recycle for treatment; Among them, the mass ratio of magnesium oxide or magnesium chloride to dissolved silicon added is 0.5 - 2∶1, and the dosage of the aggregating agent is 1 - 10 mg / L.

10. A method for efficiently removing silicon from mine brine using the system according to claim 9, characterized in that, It includes the following steps: S1. Mine brine with pH adjusted to less than 7 enters the heterogeneous membrane device, and impurities in the mine water are removed through the heterogeneous membrane, and the produced water enters the first-stage reverse osmosis device; S2. After the produced water of the heterogeneous membrane device is concentrated by the first-stage reverse osmosis device, the produced water of the first-stage reverse osmosis device enters the first reuse water tank, and the concentrated water of the first-stage reverse osmosis device enters the integrated hardness and silicon removal device; S3. The concentrated water of the first-stage reverse osmosis device enters the integrated hardness and silicon removal device, and the dissolved silicon and hardness in the first-stage reverse osmosis concentrated water are rapidly removed through chemical reactions of reagents, hardening precipitation adsorption and aggregating adsorption precipitation. The produced water of the integrated hardness and silicon removal device enters the ion exchange device; S4. The produced water of the integrated hardness and silicon removal device further removes the hardness in the water through the ion exchange device to ensure the stable operation of subsequent membranes and evaporation crystallization. The produced water of the ion exchange device enters the second-stage reverse osmosis device; S5. The produced water of the ion exchange device is concentrated by the second-stage reverse osmosis device. The produced water of the second-stage reverse osmosis device enters the second reuse water tank, and the concentrated water of the second-stage reverse osmosis device enters the electroseparation and concentration device; S6. The concentrated water of the second-stage reverse osmosis device separates salt ions and silicon through the electroseparation and concentration device. The produced water of the electroseparation and concentration device enters the filtration device, and the concentrated water of the electroseparation and concentration device enters the evaporation crystallization device to crystallize and produce salt; S7. The produced water of the electroseparation and concentration device removes the colloidal silicon that has precipitated out after concentration through the filtration device. The produced water of the filtration device enters the rapid silicon removal sedimentation device; S8. The produced water of the filtration device removes dissolved silicon through chemical reactions of reagents adsorption and aggregating adsorption precipitation. The settled sludge returns to the integrated hardness and silicon removal device through charge adsorption and network capture to strengthen the adsorption and capture effect of silicon removal precipitation. The produced water enters the ion exchange device to remove hardness and then enters the second-stage reverse osmosis device for cyclic treatment.

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