Treatment method of sodium vanadium solution wastewater

Abstract

The invention relates to the technical field of hydrometallurgy, and discloses a sodium vanadium solution wastewater treatment method, which comprises: S1, mixing sodium vanadium solution wastewater with a precipitant solution to generate a precipitate; s2, carrying out solid-liquid separation on the precipitate obtained in the step S1 to obtain supernate containing sodium vanadate; and S3, concentrating the supernate obtained in the step S2 to obtain a sodium vanadate solution. According to the scheme, the technical route of'mixed reaction-solid-liquid separation-concentration 'is adopted, efficient recovery of vanadium ions is achieved, effective removal and resource recovery of vanadium in the wastewater are guaranteed, calcium chloride which is low in price and easy to obtain serves as a precipitator, compared with other vanadium precipitation methods, the cost is lower, and the method is simple in process, low in equipment requirement, good in economical efficiency and suitable for industrial production. Vanadium in the wastewater is recovered into a sodium vanadate solution with relatively high purity, so that subsequent utilization or deep processing is facilitated, industrial wastewater recycling is realized, and the method has remarkable environmental protection value and industrial application potential and conforms to the concepts of environmental protection and sustainable development.

Description

Technical Field

[0001] The invention relates to the technical field of hydrometallurgy, and in particular to a method for treating sodium vanadium liquid wastewater. Background Art

[0002] As a key strategic metal resource, vanadium has a wide range of application values ​​in many fields such as metallurgy, aerospace, additive manufacturing and chemical industry. However, in the production process of vanadium, a large amount of wastewater is generated, which contains a large amount of harmful substances and causes serious harm to the environment and human health. Therefore, how to effectively treat these wastewaters and realize resource recovery and environmental governance has become a problem that needs to be solved urgently.

[0003] At present, the main methods for treating vanadium-containing wastewater include chemical precipitation, ion exchange, membrane separation, etc. Among them, chemical precipitation has the advantages of good treatment effect and low cost, but there are problems such as large precipitate particle size and difficulty in separation.

[0004] In the prior art, the relevant literature on vanadium extraction technology by chlorination is as follows: Patent CN110104834A discloses a method for treating vanadium-containing wastewater, which comprises: adding ferrous sulfate to the vanadium-containing wastewater for reaction; adjusting the pH of the solution to 3-4.5 after the reaction is completed, heating and stirring for reaction, adjusting the pH of the solution to 6-6.5 after a period of time, continuing stirring, and separating the solid and liquid after the reaction is completed to obtain iron vanadate precipitate and a chromium-containing solution; using aminophosphoric acid resin to adsorb the chromium-containing solution, and desorbing the aminophosphoric acid resin after the adsorption is completed to obtain a purified chromium-containing solution.

[0005] Patent CN116969626A discloses a method and system for treating vanadium-containing wastewater, which comprises: (1) mixing the vanadium-containing wastewater with ferrous salt for reaction, then adding a precipitant for reaction, adjusting the pH value of the mixed system after the reaction to 9-14, and performing solid-liquid separation; (2) using the liquid phase obtained after solid-liquid separation as vanadium-containing wastewater and repeating step (1) N times, N≥1; (3) filtering the liquid phase obtained in step (2), and then treating the filtrate with a molecular sieve to obtain treated wastewater.

[0006] Patent CN102476886A discloses a method for treating vanadium-containing wastewater, which comprises: gradually evaporating and concentrating the vanadium-containing wastewater through a first evaporator, a second evaporator and a third evaporator in sequence, a valve A between the first evaporator and the second evaporator and a valve B between the second evaporator and the third evaporator are in an open state, a valve C provided at the outlet of the third evaporator is in a closed state, and when the solid content of the mixture in the third evaporator is 55-65% by weight, the opening and closing states of valves A, B and C are appropriately controlled.

[0007] However, in the above-mentioned prior art, although the effective recovery of vanadium in vanadium-containing wastewater is achieved to a certain extent, the process is complicated, the cost is high and it is not easy to operate.

[0008] Therefore, there is still room for improvement in the prior art. Summary of the invention

[0009] In view of this, the purpose of the embodiment of the present invention is to propose a method for treating sodium vanadium liquid wastewater. The method can effectively realize the recovery of vanadium in wastewater and the utilization of resources, ensure the effective removal of vanadium in wastewater and the recovery of resources, and compared with other vanadium precipitation methods, it has low cost, simple process, low equipment requirements and good economy, and recovers vanadium in wastewater into sodium vanadate solution with high purity, which is convenient for subsequent utilization or deep processing, realizes the resource utilization of industrial wastewater, and has significant environmental protection value and industrial application potential.

[0010] Based on the above purpose, the embodiment of the present invention provides a method for treating sodium vanadium liquid wastewater, comprising: S1, mixing the sodium vanadium liquid wastewater with a precipitant solution to generate a precipitate; S2, performing solid-liquid separation on the precipitate in S1 to obtain a supernatant containing sodium vanadate; S3, concentrating the supernatant obtained in S2 to obtain a sodium vanadate solution.

[0011] According to one embodiment of the present invention, in step S1, the molar ratio of the sodium vanadium liquid wastewater to the precipitant solution is 1:1-1.5.

[0012] According to one embodiment of the present invention, in step S1, during the stirring process, the precipitant solution reacts with vanadium ions in the sodium vanadium liquid wastewater to generate a precipitate.

[0013] According to one embodiment of the present invention, in step S1, the precipitant solution includes a calcium chloride solution.

[0014] According to one embodiment of the present invention, in step S1, the sodium vanadium liquid wastewater is mixed with the precipitant solution and then stirred evenly.

[0015] According to one embodiment of the present invention, in step S1, the stirring time is 30 to 60 minutes.

[0016] According to one embodiment of the present invention, in step S1, the generated precipitate includes calcium vanadate.

[0017] According to one embodiment of the present invention, in step S2, the solid-liquid separation method includes filtration, sedimentation and centrifugation.

[0018] According to one embodiment of the present invention, in step S3, the concentration includes evaporation concentration and membrane separation concentration.

[0019] According to one embodiment of the present invention, in step S3, the concentration of vanadium ions in the sodium vanadate solution is 1.5 to 2 times the concentration of vanadium ions in the sodium vanadium liquid wastewater.

[0020] The present invention has at least the following beneficial technical effects: The invention treats sodium vanadium liquid wastewater by precipitating vanadium with calcium chloride, adopts the technical route of "mixed reaction-solid-liquid separation-concentration", realizes efficient recovery of vanadium ions, ensures effective removal of vanadium in wastewater and resource recovery, and calcium chloride is a cheap and readily available precipitant. Compared with other vanadium precipitation methods, the cost is lower. The method of the invention has simple process, low equipment requirements and good economy, recovers vanadium in wastewater into sodium vanadate solution with higher purity, is convenient for subsequent utilization or deep processing, realizes resource utilization of industrial wastewater, has significant environmental protection value and industrial application potential, and conforms to the concepts of green environmental protection and sustainable development. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in conjunction with specific embodiments.

[0022] The terms "including" and "having" and any variations thereof in the specification and claims of the present invention are intended to cover non-exclusive inclusions; the terms "first", "second", etc. in the specification and claims of the present invention are used to distinguish different objects rather than to describe a specific order. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0023] In addition, reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0024] The present invention provides a method for treating sodium vanadium liquid wastewater, comprising the following steps: S1, mixing the sodium vanadium liquid wastewater with a precipitant solution to generate a precipitate; S2, performing solid-liquid separation on the precipitate in S1 to obtain a supernatant containing sodium vanadate; S3, concentrating the supernatant obtained in S2 to obtain a sodium vanadate solution.

[0025] According to one embodiment of the present invention, the main component contained in the sodium vanadium liquid wastewater is vanadium ions, which is an important resource, and its recovery has economic value and environmental significance. Calcium chloride solution is used as a precipitant to react with vanadium ions in the wastewater to generate precipitation. The present invention is based on the principle that vanadium ions in the sodium vanadium liquid wastewater react with calcium chloride solution to generate precipitation, and calcium chloride solution is used as a precipitant. The vanadium ions in the sodium vanadium liquid wastewater are combined with calcium ions in the calcium chloride solution to generate water-insoluble calcium vanadate precipitation, and the sodium ions in the sodium vanadium liquid wastewater and the chloride ions in the calcium chloride solution form a water-soluble byproduct sodium chloride. After the above reaction, the vanadate ions remaining in the solution that have not been completely reacted and precipitated are combined with sodium ions to form dissolved sodium vanadate, which remains in the supernatant.

[0026] According to one embodiment of the present invention, sodium vanadium liquid wastewater and calcium chloride solution are mixed in a certain proportion and stirred evenly to ensure that the two are fully contacted and reacted. The molar ratio of sodium vanadium liquid wastewater to calcium chloride solution is 1:1-1.5. When the molar ratio is 1:1, the two can react completely in theory. When the molar ratio is 1:1.5, a small amount of calcium chloride is added to ensure that the vanadium ions are completely precipitated. The stirring time is 30-60 minutes to ensure that the vanadium ions react fully with the calcium chloride.

[0027] According to one embodiment of the present invention, the reaction mixture is subjected to solid-liquid separation to obtain a precipitate and a supernatant, wherein the precipitate includes a calcium vanadate precipitate, and the supernatant is a solution containing sodium vanadate. The solid-liquid separation method includes a filtration method, a sedimentation method, and a centrifugation method. The filtration method separates the precipitate and the supernatant through a filtration device. The sedimentation method separates the precipitate through natural sedimentation or after adding a sedimentation aid. The centrifugation method uses centrifugal force to separate solids and liquids.

[0028] According to one embodiment of the present invention, the supernatant obtained by solid-liquid separation is concentrated to further increase the vanadium ion concentration of the sodium vanadate solution. The concentration method includes evaporation concentration and membrane separation concentration. Evaporation concentration evaporates part of the solvent by heating to increase the vanadium ion concentration. Membrane separation concentration separates the solvent by selective membrane technology to increase the vanadium ion concentration. The vanadium ion concentration in the sodium vanadate solution obtained after concentration is 1.5 to 2 times the vanadium ion concentration in the sodium vanadium liquid wastewater. The vanadium ions are converted into a recyclable sodium vanadate solution through reaction, and the resource utilization rate is significantly improved. Through precise separation and concentration, a sodium vanadate solution with higher purity is obtained, which reduces the interference of impurities and is conducive to subsequent industrial processing.

[0029] The method for treating sodium vanadium liquid wastewater by using calcium chloride to precipitate vanadium proposed in the present invention can significantly reduce wastewater pollution through efficient recovery and resource utilization of vanadium ions, and has a simple process and low cost, and has great promotion and application value. The technical route of "mixed reaction-solid-liquid separation-concentration" is adopted to achieve efficient recovery of vanadium ions, ensure the effective removal and resource recovery of vanadium in wastewater, and calcium chloride is a cheap and easily available precipitant, which is lower in cost than other vanadium precipitation methods. The required equipment such as stirring device, filtering device and evaporating device are all conventional equipment, and the investment cost is low. The method of the present invention has a simple process, low equipment requirements, and good economy. The vanadium in the wastewater is recovered as a sodium vanadate solution with a higher purity, which is convenient for subsequent utilization or deep processing, and realizes the resource utilization of industrial wastewater. It has significant environmental protection value and industrial application potential, and is in line with the concept of green environmental protection and sustainable development.

[0030] According to one embodiment of the present invention, in step S1, the molar ratio of the sodium vanadium liquid wastewater to the precipitant solution is 1:1-1.5.

[0031] According to one embodiment of the present invention, in step S1, during the stirring process, the precipitant solution reacts with vanadium ions in the sodium vanadium liquid wastewater to generate a precipitate.

[0032] According to one embodiment of the present invention, in step S1, the precipitant solution includes a calcium chloride solution.

[0033] According to one embodiment of the present invention, in step S1, the sodium vanadium liquid wastewater is mixed with the precipitant solution and then stirred evenly.

[0034] According to one embodiment of the present invention, in step S1, the stirring time is 30 to 60 minutes.

[0035] According to one embodiment of the present invention, in step S1, the generated precipitate includes calcium vanadate.

[0036] In step S1 of the present invention, sodium vanadium liquid wastewater is mixed with calcium chloride solution, and the precipitation reaction of vanadium ions is ensured to be fully carried out by controlling the molar ratio and stirring time. A reasonable molar ratio range (1:1~1.5) balances the reaction efficiency and economy. Calcium chloride reacts rapidly, generates precipitation with high efficiency, and can effectively reduce the concentration of vanadium ions in wastewater. The use of calcium chloride solution as a precipitant is low in cost, and the reaction conditions are mild. The reaction can be completed at room temperature and pressure, without the need for complex temperature control equipment or high-pressure devices, thereby reducing energy consumption. The equipment requirements are low, and the overall operating cost is low. The by-products generated during the reaction are non-toxic and easy to handle, without the need for high waste residue treatment costs, and will not cause secondary pollution to the environment. The process flow of the present invention is short, the steps are simple, and the parameters (such as stirring time, molar ratio, etc.) can be adjusted according to specific needs. Compared with the existing complex process, it is more energy-efficient and efficient, and is convenient for industrial promotion.

[0037] According to one embodiment of the present invention, in step S2, the solid-liquid separation method includes filtration, sedimentation and centrifugation.

[0038] In step S2 of the present invention, the generated calcium vanadate precipitate is separated from the liquid by filtration, centrifugation or sedimentation to obtain a supernatant containing sodium vanadate, thereby reducing the difficulty of subsequent treatment. Different solid-liquid separation methods can be selected according to the characteristics of the wastewater to meet the needs of various industrial scenarios. After solid-liquid separation, the vanadium ion concentration in the supernatant is greatly reduced, which meets the requirements of environmental protection emissions and reduces pollution to water bodies and soil.

[0039] According to one embodiment of the present invention, in step S3, the concentration includes evaporation concentration and membrane separation concentration.

[0040] According to one embodiment of the present invention, in step S3, the concentration of vanadium ions in the sodium vanadate solution is 1.5 to 2 times the concentration of vanadium ions in the sodium vanadium liquid wastewater.

[0041] Step S3 of the present invention adopts evaporation or membrane separation technology to remove solvent (such as water) and increase the concentration of sodium vanadate solution. The selection of different concentration methods depends on the volume of wastewater and the vanadium content. The vanadium ions are recovered in the form of sodium vanadate with high purity, which is convenient for subsequent utilization, realizes the resource utilization of wastewater, effectively reduces the concentration of vanadium ions in wastewater, and reduces the pollution of heavy metals to the environment. It can be widely used in the field of vanadium-containing wastewater treatment in metallurgy, chemical industry, mining enterprises, etc., and is particularly suitable for the recycling and utilization of sodium vanadium liquid wastewater discharge. Through the recovery and efficient separation of vanadium resources, the treatment burden of industrial wastewater is greatly reduced, which is in line with the concept of green manufacturing and circular economy. The process parameters are simple and easy to control, and large-scale continuous processing can be achieved, with good economy and operability.

[0042] The present invention is further explained below in conjunction with specific embodiments and comparative examples.

[0043] Example 1 Take 1000mL of sodium vanadium liquid wastewater with a vanadium ion concentration of 10g / L, mix it with 1000mL of calcium chloride solution (concentration of 10%), stir evenly, and stir for 40 minutes. Then use filtration to separate the solid and liquid to obtain a supernatant containing sodium vanadate. Evaporate and concentrate the supernatant to obtain a sodium vanadate solution with a vanadium ion concentration of 20g / L.

[0044] Example 2 Take 2000mL of sodium vanadium liquid wastewater with a vanadium ion concentration of 20g / L, mix it with 2000mL of calcium chloride solution (concentration of 15%), stir evenly, and stir for 50 minutes. Then use sedimentation method to separate solid and liquid to obtain supernatant containing sodium vanadate. The supernatant is concentrated by membrane separation to obtain sodium vanadate solution with a vanadium ion concentration of 30g / L.

[0045] Example 3 Take 1500mL of sodium vanadium liquid wastewater with a vanadium ion concentration of 15g / L, mix it with 1500mL of calcium chloride solution (concentration of 12%), stir evenly, and stir for 30 minutes. Then use centrifugation to separate the solid and liquid to obtain a supernatant containing sodium vanadate. Evaporate and concentrate the supernatant to obtain a sodium vanadate solution with a vanadium ion concentration of 25g / L.

[0046] The method for treating sodium vanadium liquid wastewater by using calcium chloride to precipitate vanadium proposed in the present invention can significantly reduce wastewater pollution through efficient recovery and resource utilization of vanadium ions, and has a simple process and low cost, and has great promotion and application value. The technical route of "mixed reaction-solid-liquid separation-concentration" is adopted to achieve efficient recovery of vanadium ions, ensure the effective removal and resource recovery of vanadium in wastewater, and calcium chloride is a cheap and easily available precipitant, which is lower in cost than other vanadium precipitation methods. The required equipment such as stirring device, filtering device and evaporating device are all conventional equipment, and the investment cost is low. The method of the present invention has a simple process, low equipment requirements, and good economy. The vanadium in the wastewater is recovered as a sodium vanadate solution with a higher purity, which is convenient for subsequent utilization or deep processing, and realizes the resource utilization of industrial wastewater. It has significant environmental protection value and industrial application potential, and is in line with the concept of green environmental protection and sustainable development.

[0047] The above are exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications may be made without departing from the scope disclosed in the embodiments of the present invention as defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.

[0048] It should be understood that, as used herein, the singular forms "a", "an" are intended to include the plural forms as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations including one or more of the associated listed items.

[0049] The serial numbers of the embodiments disclosed in the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0050] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the above embodiments of the present invention, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A method for treating sodium vanadium liquid wastewater, characterized in that: include: S1, mixing the sodium vanadium liquid wastewater with a precipitant solution to generate a precipitate; S2, performing solid-liquid separation on the precipitate in S1 to obtain a supernatant containing sodium vanadate; S3, concentrating the supernatant obtained in S2 to obtain a sodium vanadate solution.

2. The method for treating sodium vanadium liquid wastewater according to claim 1, characterized in that: In step S1, the molar ratio of sodium vanadium liquid wastewater to the precipitant solution is 1:1-1.

5.

3. The method for treating sodium vanadium liquid wastewater according to claim 1, characterized in that: In step S1, during the stirring process, the precipitant solution reacts with vanadium ions in the sodium vanadium liquid wastewater to generate a precipitate.

4. The method for treating sodium vanadium liquid wastewater according to claim 1, characterized in that: In step S1, the precipitant solution includes a calcium chloride solution.

5. The method for treating sodium vanadium liquid wastewater according to claim 1, characterized in that: In step S1, the sodium vanadium liquid wastewater and the precipitant solution are mixed and stirred evenly.

6. The method for treating sodium vanadium liquid wastewater according to claim 5, characterized in that: In step S1, the stirring time is 30 to 60 minutes.

7. The method for treating sodium vanadium liquid wastewater according to claim 1, characterized in that: In step S1, the generated precipitate includes calcium vanadate.

8. The method for treating sodium vanadium liquid wastewater according to claim 1, characterized in that: In step S2, the solid-liquid separation method includes filtration, sedimentation and centrifugation.

9. The method for treating sodium vanadium liquid wastewater according to claim 1, characterized in that: In step S3, concentration includes evaporation concentration and membrane separation concentration.

10. The method for treating sodium vanadium liquid wastewater according to claim 1, characterized in that: In step S3, the vanadium ion concentration in the sodium vanadate solution is 1.5 to 2 times the vanadium ion concentration in the sodium vanadium liquid wastewater.