Defluorination treatment equipment for low-grade fluorite acid-making sewage

Abstract

The utility model discloses defluorination treatment equipment for low-grade fluorite acid-making sewage, which belongs to the technical field of sewage treatment and comprises a neutralizing tank, a primary sedimentation tank, an advanced treatment tank, a secondary sedimentation tank and a landscape tank which are sequentially arranged along the flowing direction of the sewage, and a flocculant adding tank is arranged at an output port of the deep treatment tank. Sewage is pumped into the neutralizing tank through the lifting pump, an acid-base neutralization reaction is carried out in the neutralizing tank to form insoluble compounds, and the insoluble compounds enter the primary settling tank to be settled, so that most fluorine ions in the sewage are removed. And the neutralized sewage enters a deep treatment tank for deep treatment. Different from an integrated treatment mode, various parameters related to the technological process can be more accurately controlled through stage treatment, the condition of each process is convenient to regulate and control, sewage removal substances and various agents have a better binding rate in the reaction process, and the fluorine removal rate is increased.

Description

Technical Field

[0001] This utility model belongs to the field of wastewater treatment technology, specifically a defluorination treatment device for low-grade fluorite acid production wastewater. Background Technology

[0002] Low-grade fluorite resources are widely found in my country's fluorite deposits, and the development and utilization of associated fluorite has become an important task in meeting the strategic mineral resource needs. Low-grade fluorite contains high levels of impurities and easily generates complex wastewater during smelting. With increasingly stringent environmental regulations, the efficient utilization of low-grade fluorite has become a crucial aspect of green mining development. However, in the production of anhydrous hydrogen fluoride from low-grade fluorite, the wastewater has a high fluoride content and is accompanied by a large amount of other harmful substances, making wastewater treatment more complex.

[0003] Currently, traditional wastewater defluoridation processes generally face problems such as low defluoridation efficiency, cumbersome treatment procedures, high operating costs, and high labor intensity. Patent CN219885718U discloses an integrated wastewater treatment system for dry powder defluoridating agent dosing and storage. Wastewater is lifted by a feeder into a reaction tank to react with the defluoridating agent, then sequentially undergoes flocculation treatment in a flocculation tank and sedimentation treatment in a sedimentation tank before finally being discharged from an effluent tank. This treatment system achieves an automated process for treating fluoride-containing wastewater; however, the treatment process is relatively crude, lacking precise control over the series of processes involved in the reaction. Utility Model Content

[0004] The purpose of this invention is to provide a defluorination treatment device for low-grade fluorite acid production wastewater to solve the problems mentioned in the prior art.

[0005] A defluoridation treatment device for low-grade fluorite-based acid production wastewater is provided, comprising:

[0006] The system consists of a neutralization tank, a primary sedimentation tank, a deep treatment tank, a secondary sedimentation tank, and a landscape tank arranged sequentially along the direction of sewage flow. The deep treatment tank has a chemical dosing tank at its inlet and a flocculant dosing tank at its outlet.

[0007] Furthermore, the neutralization tank is connected to a lime slurry dosing tank. Wastewater first enters the pre-treatment equalization tank for collection, and is then pumped to the neutralization tank by a lift pump. The wastewater in the neutralization tank undergoes an acid-base neutralization reaction with the lime slurry delivered by the conveying pump on the lime slurry dosing tank, causing fluoride ions to react with calcium ions to form calcium fluoride precipitate, thereby removing most of the fluoride ions from the wastewater.

[0008] Furthermore, the secondary sedimentation tank is an inclined tube sedimentation tank. Wastewater enters the secondary sedimentation tank, where the inclined tube structure enhances the efficiency and effectiveness of the sedimentation process. The inclined tube sedimentation tank increases the sedimentation surface area and shortens the particle settling path, enabling suspended particles to complete sedimentation and separation in a shorter time.

[0009] Furthermore, the primary sedimentation tank is connected to a first pH adjustment tank. By adjusting the pH value, the environmental conditions for the precipitation reaction in the primary sedimentation tank are controlled, making the generated compounds more stable and the precipitation more thorough, while avoiding secondary pollution caused by excessive addition of reagents.

[0010] Furthermore, the advanced treatment tank is connected to a second pH adjustment tank. Adjusting the pH value within the advanced treatment tank optimizes the chemical reaction rate and the properties of the products, enhancing defluoridation and flocculation effects. Precise pH adjustment within the advanced treatment tank significantly improves the effectiveness of the advanced treatment, further removing residual fluoride ions and other impurities, providing a crucial guarantee for effluent meeting discharge standards.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0012] Wastewater is pumped to a neutralization tank, where an acid-base neutralization reaction occurs to form insoluble compounds. These compounds then settle in a primary sedimentation tank, removing most of the fluoride ions from the wastewater. The neutralized wastewater then proceeds to a secondary treatment tank for further treatment. Unlike integrated treatment methods, staged treatment allows for more precise control of various process parameters, facilitating the regulation of each process step. It also ensures better binding rates between the wastewater residues and the reagents during the reaction process, thereby improving the fluoride removal rate. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this drawing or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this drawing. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0014] Figure 1 A schematic diagram of the overall structure of a defluorination treatment device for low-grade fluorite acid production wastewater.

[0015] In the diagram: 1. Neutralization tank; 11. Lime slurry dosing tank; 2. Primary sedimentation tank; 21. First pH adjustment tank; 3. Advanced treatment tank; 31. Chemical dosing tank; 32. Flocculant dosing tank; 33. Second pH adjustment tank; 4. Secondary sedimentation tank; 5. Landscape pond. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this application clearer, the application is described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0017] Obviously, the accompanying drawings described below are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0018] However, there may be instances where unnecessary detailed descriptions are omitted. For example, detailed descriptions of well-known matters or repetitive descriptions of essentially the same structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0019] Please see Figure 1 As shown in the embodiment of this utility model, it includes a neutralization tank 1, a primary sedimentation tank 2, a deep treatment tank 3, a secondary sedimentation tank 4, and a landscape tank 5 arranged sequentially along the sewage flow direction. The inlet of the deep treatment tank 3 is provided with a chemical dosing tank 31, and the outlet of the deep treatment tank 3 is provided with a flocculant dosing tank 32.

[0020] Wastewater is pumped to neutralization tank 1 by a lift pump, where an acid-base neutralization reaction occurs to form insoluble compounds. The neutralized wastewater then enters primary sedimentation tank 2 for concentration and sedimentation, thereby removing most of the fluoride ions. The supernatant from primary sedimentation tank 2 overflows into advanced treatment tank 3. A high-efficiency defluoridating agent is added at the inlet of advanced treatment tank 3, and after mixing, it enters the advanced treatment tank 3 for thorough reaction. Flocculant is added at the outlet of advanced treatment tank 3. The defluoridating agent complexes with fluoride ions in the water to form stable macromolecular long-chain polymers. Through charge neutralization, double-layer compression, adsorption bridging, and sedimentation trapping, it co-precipitates with the added flocculant, further removing fluoride from the wastewater. Finally, after exiting advanced treatment tank 3, the wastewater enters secondary sedimentation tank 4 to settle the reacted flocculants. The settled wastewater overflows into landscape pond 5 for discharge.

[0021] Specifically, the neutralization tank 1 is connected to the lime slurry addition tank 11. Wastewater first enters the pre-treatment regulating tank for collection, and is then pumped to the neutralization tank 1 by a lift pump. The wastewater in the neutralization tank 1 undergoes an acid-base neutralization reaction with the lime slurry delivered by the conveying pump on the lime slurry addition tank 11, causing fluoride ions and calcium ions to form calcium fluoride precipitate, thereby removing most of the fluoride ions from the wastewater.

[0022] Through tiered treatment, each treatment unit achieves targeted removal at different stages. Neutralization tank 1 utilizes acid-base neutralization reactions to generate sparingly soluble compounds; primary sedimentation tank 2 removes large particulate impurities and thus most fluoride ions through gravity; advanced treatment tank 3 optimizes chemical reactions and flocculation effects by adding reagents; and secondary sedimentation tank 4 improves sedimentation efficiency. The entire process optimizes reaction conditions at each stage, resulting in higher fluoride removal efficiency, precise and controllable process flow, and significantly reduced operating costs.

[0023] The primary sedimentation tank 2 is connected to the first pH adjustment tank 21, and the advanced treatment tank 3 is connected to the second pH adjustment tank 33. The addition of the defluoridating agent is based on previous experimental results and relevant data, comprehensively considering the fluoride ion concentration in the wastewater before dosing, the agent's removal effect on fluoride ions, and the cost of dosing. During operation, the pH value of the primary sedimentation tank 2 is controlled between 9.5 and 12.0, and the pH value of the advanced treatment tank 3 is controlled between 6.0 and 9.0. The frequency of the defluoridating agent pump and the pH value are automatically controlled by PID to ensure that the wastewater residence time in the advanced treatment tank is more than 10 minutes, thus ensuring the defluoridation effect.

[0024] Example 1

[0025] (I) Operating Time and Monitoring

[0026] A five-day operational test was conducted, with continuous monitoring of the influent and effluent water quality. Key monitoring indicators included fluoride ion concentration, pH value, COD, ammonia nitrogen, suspended solids, and total dissolved solids. Monitoring results showed that the fluoride ion concentration in the pre-treatment equalization tank ranged from 10.8 mg / L to 24.14 mg / L; the fluoride ion concentration in primary sedimentation tank 2 ranged from 10.32 mg / L to 13.52 mg / L; and the effluent fluoride ion concentration ranged from 2.24 mg / L to 4.49 mg / L, with an average of 3.4 mg / L, far below the discharge standard of 6.0 mg / L. All other indicators met the discharge requirements.

[0027] (II) Control of process operating parameters

[0028] 1. Dosing of defluoridating agents: During operation, the pH value of the primary sedimentation tank 2 is controlled between 9.5 and 12.0, and the pH value of the deep treatment tank 3 is controlled between 6.5 and 9.0. Through the PID automatic dosing system, the pH value in the deep treatment tank 3 is set to 7.5, and the frequency of the defluoridating agent pump is controlled to accurately add the agent, meet the process requirements, and achieve a good defluoridation effect.

[0029] 2. Reaction time control: Wastewater treatment capacity 40m³ 3 / h, the retention time of wastewater in the deep treatment tank is 22 minutes.

[0030] Example 2

[0031] (I) Operating Time and Monitoring

[0032] A 10-day operational test was conducted, with continuous monitoring of the influent and effluent water quality. Key monitoring indicators included fluoride ion concentration, pH value, COD, ammonia nitrogen, suspended solids, and total dissolved solids. Monitoring results showed that the fluoride ion concentration in the pre-treatment equalization tank ranged from 78.3 mg / L to 482.0 mg / L; the fluoride ion concentration in the primary sedimentation tank 2 ranged from 11.26 mg / L to 18.91 mg / L; and the effluent fluoride ion concentration ranged from 1.56 mg / L to 3.82 mg / L, with an average of 2.6 mg / L, far below the discharge standard of 6 mg / L. All other indicators met the discharge requirements.

[0033] (II) Control of process operating parameters

[0034] 1. Dosing of defluoridating agents: During the operation phase, the pH value of the primary sedimentation tank 2 is adjusted between 10.0 and 12.0, and the pH value of the deep treatment tank 3 is controlled between 6.0 and 8.5. Through the PID automatic dosing system, the pH value in the deep treatment tank 3 is set to 7.0, and the frequency of the defluoridating agent pump is controlled to accurately add the agent, meet the process requirements, and achieve a good defluoridation effect.

[0035] 2. Reaction time control: Wastewater treatment capacity is 35m³. 3 / h, the retention time of wastewater in the deep treatment tank is 25 minutes.

[0036] Example 3

[0037] (I) Operating Time and Monitoring

[0038] A 15-day operational test was conducted, with continuous monitoring of the influent and effluent water quality. Key monitoring indicators included fluoride ion concentration, pH value, COD, ammonia nitrogen, suspended solids, and total dissolved solids. Monitoring results showed that the fluoride ion concentration in the pre-treatment equalization tank ranged from 15.6 mg / L to 163.2 mg / L; the fluoride ion concentration in primary sedimentation tank 2 ranged from 12.23 mg / L to 20.48 mg / L; and the effluent fluoride ion concentration ranged from 1.12 mg / L to 2.98 mg / L, with an average concentration of 2.0 mg / L, far below the discharge standard of 6 mg / L. All other indicators met the discharge requirements.

[0039] (II) Control of process operating parameters

[0040] 1. Dosing of defluoridating agents: During the operation phase, the pH value of the sedimentation tank 2 is controlled between 9.0 and 11.5, and the pH value of the deep treatment tank 3 is controlled between 7.0 and 9.0. Through the PID automatic control dosing system, the pH value in the deep treatment tank 3 is set to 8.0, and the frequency of the defluoridating agent pump is controlled to accurately add the agent, meet the process requirements, and achieve a good defluoridation effect.

[0041] 2. Reaction time control: Wastewater treatment capacity is 20m³. 3 / h, the wastewater stays in the deep treatment tank for about 45 minutes.

[0042] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A defluoridation treatment device for low-grade fluorite-based acid production wastewater, characterized in that, include: The following structures are arranged sequentially along the direction of sewage flow: neutralization tank (1), primary sedimentation tank (2), deep treatment tank (3), secondary sedimentation tank (4), and landscape tank (5). The deep treatment tank (3) is equipped with a chemical dosing tank (31) at its inlet and a flocculant dosing tank (32) at its outlet.

2. The defluorination treatment equipment for low-grade fluorite-based acid production wastewater according to claim 1, characterized in that, The neutralization tank (1) is connected to a lime slurry dosing tank (11).

3. The defluorination treatment equipment for low-grade fluorite-based acid production wastewater according to claim 1, characterized in that, The secondary sedimentation tank (4) is an inclined tube sedimentation tank.

4. The defluoridation treatment equipment for low-grade fluorite-based acid production wastewater according to claim 1, characterized in that, The primary sedimentation tank (2) is connected to a first pH adjustment tank (21).

5. The defluorination treatment equipment for low-grade fluorite-based acid production wastewater according to claim 1, characterized in that, The deep treatment tank (3) is connected to a second pH adjustment tank (33).

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