A process for removing arsenic from feed-grade copper sulfate

Abstract

The present application relates to the field of copper sulfate extraction, and specifically discloses a feed-grade copper sulfate arsenic removal treatment process. A feed-grade copper sulfate arsenic removal treatment process includes oxidation treatment, pH adjustment treatment, plasma electrolysis treatment and infrared adsorption purification treatment of PCB etching waste liquid in sequence. In the plasma electrolysis treatment step, the PCB etching waste liquid that has been treated with pH adjustment passes through a plasma generating device to electrolyze and generate plasma. In the infrared adsorption purification step, the PCB etching waste liquid that has been treated with the plasma electrolysis treatment step is heated by an infrared heating device, and then an adsorbent is added for adsorption and sedimentation. The present application forms a set of efficient arsenic removal treatment processes by combining multiple steps such as oxidation treatment, pH adjustment treatment, plasma electrolysis treatment and infrared adsorption purification treatment. This comprehensive treatment method can significantly improve the arsenic removal efficiency and reduce the treatment cost.

Description

Technical Field

[0001] The present invention relates to the field of copper sulfate extraction, and more specifically, to a feed-grade copper sulfate arsenic removal treatment process. Background Art

[0002] Copper, as an essential trace element in animals, participates in the metabolism of nutrients such as protein, fat, carbohydrates and vitamins, and can effectively improve the utilization rate of nutrients in feed. Copper is also involved in the regulation of the body's immune function. Copper deficiency may cause a decline in immune function. Adding copper sulfate in appropriate amounts can enhance the disease resistance of animals. For some animals, such as sheep, copper sulfate can also increase wool production and improve wool quality. Therefore, copper sulfate is an important trace element drug additive required for animal feed.

[0003] At present, feed-grade copper sulfate used as feed additive is almost always produced from copper-containing circuit board etching waste liquid. The arsenic in printed circuit board etching waste liquid (hereinafter referred to as "PCB etching waste liquid") mainly comes from the manufacture of copper-clad boards, and the copper sulfate additive produced from PCB etching waste liquid has strict requirements on arsenic, and the content is required to be less than 5ppm.

[0004] At present, the methods for removing arsenic from copper sulfate solution include extraction, resin, phosphating, etc., but these methods have the disadvantages of narrow application range, long process, high cost, and easy introduction of other impurities. In addition, the existence of arsenic in copper sulfate solution is complex and difficult to remove and purify deeply. Summary of the invention

[0005] In order to provide a treatment process that is efficient, low-cost and can ensure good arsenic removal effects, the present application provides a feed-grade copper sulfate arsenic removal treatment process.

[0006] The present application provides a feed-grade copper sulfate arsenic removal treatment process using the following technical solutions:

[0007] A feed-grade copper sulfate arsenic removal treatment process, characterized in that the feed-grade copper sulfate arsenic removal treatment process comprises oxidation treatment, pH adjustment treatment, plasma electrolysis treatment and infrared adsorption purification treatment of PCB etching waste liquid in sequence;

[0008] In the plasma electrolysis treatment step, the PCB etching waste liquid that has been treated with pH adjustment passes through the plasma generating device along the electric field direction parallel to the plasma generating electrode of the plasma generating device, so that the PCB etching waste liquid generates a plasma that is electrically neutral as a whole and includes electrons, positive ions, neutral particles, and free radicals; and the surfaces of arsenate and arsenite particles in the PCB etching waste liquid are charged; the plasma reacts with the arsenate and arsenite particles with charged surfaces in the PCB etching waste liquid to generate a catalytic activated high-energy arsenic-containing complex;

[0009] In the infrared adsorption purification treatment step, the PCB etching waste liquid treated in the plasma electrolysis treatment step is heated by an infrared heating device, so that the activated high-energy arsenic-containing complex in the PCB etching waste liquid absorbs infrared energy and further reacts with the plasma remaining in the PCB etching waste liquid, and then an infrared spectrum molecular sieve adsorbent is added to adsorb and precipitate the activated high-energy arsenic-containing complex, and then filtered to obtain a copper sulfate solution.

[0010] By adopting the above technical solution, through plasma electrolysis treatment, the surface of arsenate and arsenite particles in PCB etching waste liquid can be charged, and react with the generated plasma to form catalytic activated high-energy arsenic-containing complexes. This treatment method can effectively separate arsenic from copper sulfate solution and form catalytic activated high-energy arsenic-containing complexes, thereby facilitating subsequent infrared adsorption purification treatment.

[0011] Infrared heating enables the activated high-energy arsenic-containing complexes (such as AsO4-NO3, AsO3-NO2) in the PCB etching waste liquid to absorb infrared energy. This energy absorption not only enhances the activity of the activated high-energy arsenic-containing complexes, but also promotes their further interaction with the plasma (including electrons, positive ions, neutral particles and free radicals) remaining in the waste liquid. This interaction may include charge exchange, free radical reaction, etc., which helps to convert the activated high-energy arsenic-containing complexes into a form that is easier to adsorb, thereby improving their adsorption.

[0012] Infrared heating can also improve the adsorption capacity of infrared spectroscopy molecular sieve adsorbents by directly acting on them. Infrared radiation may cause the pore structure of the molecular sieve to be more open, thereby increasing its specific surface area and adsorption sites. In addition, infrared radiation may also excite the active sites or groups on the surface of the molecular sieve, thereby enhancing the interaction between it and the target substance (i.e., the activated high-energy arsenic-containing complex). This enhanced interaction not only improves the adsorption efficiency of the adsorbent, but also accelerates the kinetics of the adsorption process.

[0013] In summary, this technical solution achieves efficient and selective removal of arsenic in copper sulfate solution by combining efficient physical and chemical methods, and has the advantages of environmental protection, stability, strong operability and high cost-effectiveness.

[0014] Optionally, in the infrared adsorption purification step, the infrared spectrum molecular sieve adsorbent is 13X molecular sieve or 4A molecular sieve.

[0015] Optionally, the infrared heating device includes an infrared emitter and a liquid containing chamber, a plurality of columns are provided in the liquid containing chamber, the plurality of columns enable the liquid to flow in an S-shape, and the infrared emitter outputs infrared light with a wavelength of 2500-10000nm.

[0016] By adopting the above technical solution, the infrared heating device heats the PCB etching waste liquid by emitting 2500-10000nm infrared light, so that the activated high-energy arsenic-containing complex absorbs infrared energy, further promoting its interaction with plasma.

[0017] The addition of infrared spectrum molecular sieve adsorbent (such as 13X molecular sieve or 4A molecular sieve), infrared light in the above wavelength range can improve the adsorption performance of 13X molecular sieve or 4A molecular sieve, and can efficiently adsorb, precipitate and activate high-energy arsenic-containing complexes, thereby achieving efficient removal of arsenic. The filtration step finally obtains a copper sulfate solution with a low arsenic content, which meets the quality requirements of feed-grade copper sulfate.

[0018] Optionally, the oxidation treatment includes: adding an oxidant to the PCB etching waste liquid under stirring conditions until the PCB etching waste liquid becomes clear and transparent, and standing for 2-4 hours to obtain a coarse etching waste liquid.

[0019] Optionally, the oxidant includes any one of H2O2, potassium permanganate, and manganese dioxide.

[0020] By adopting the above technical scheme, oxidation treatment oxidizes organic and inorganic pollutants, including arsenic compounds, in PCB etching waste liquid by adding oxidants (such as H2O2, potassium permanganate, manganese dioxide). This helps to convert arsenic into a form that is easier to remove while reducing the toxicity of the waste liquid.

[0021] Adding the oxidant under stirring conditions ensures the uniform distribution and reaction effect of the oxidant, and the crude etching waste liquid obtained after standing provides conditions for subsequent pH adjustment treatment.

[0022] Optionally, the pH adjustment treatment includes: adding a solution containing trivalent iron to the rough etching waste liquid under stirring conditions, the amount of which is: 2-4 kg Fe per cubic meter of the rough etching waste liquid. 3+ .

[0023] By adopting the above technical solution, the addition of trivalent iron ions will affect the pH value of the solution, which helps to adjust the solution to a pH range suitable for subsequent treatment. The appropriate pH value helps to improve the treatment efficiency of ion electrolysis treatment and infrared adsorption purification treatment.

[0024] Optionally, the plasma generating device further comprises a liquid level sensor and a temperature sensor, and the liquid level sensor and the temperature sensor are used for real-time monitoring of the liquid level height and temperature in the plasma generating device.

[0025] By adopting the above technical solution, the liquid level sensor and temperature sensor in the plasma generator can monitor the liquid level and temperature in the device in real time, ensuring that the treatment process is carried out under safe and stable conditions. This helps to prevent equipment failure or safety accidents caused by excessively high liquid levels or abnormal temperatures, and ensures the stability and reliability of the treatment process.

[0026] In summary, this application has the following beneficial effects:

[0027] 1. This process combines oxidation treatment, pH adjustment treatment, plasma electrolysis treatment and infrared adsorption purification treatment to form a set of efficient arsenic removal treatment process. This comprehensive treatment method can significantly improve arsenic removal efficiency and reduce treatment costs.

[0028] In particular, the steps of plasma electrolysis treatment and infrared adsorption purification treatment effectively promote the conversion and removal of arsenic by generating high-energy plasma and infrared heating, thereby achieving the treatment goal of high efficiency and low cost. Since the present application adopts infrared adsorption purification treatment operation, infrared heating enables the activated high-energy arsenic-containing complexes (such as AsO4-NO3, AsO3-NO2) in the PCB etching waste liquid to absorb infrared energy. The absorption of this energy not only enhances the activity of the activated high-energy arsenic-containing complexes, but also promotes their further interaction with the plasma (including electrons, positive ions, neutral particles and free radicals) remaining in the waste liquid. This effect may include charge exchange, free radical reaction, etc., which helps to convert the activated high-energy arsenic-containing complexes into a form that is easier to adsorb, thereby improving its adsorption.

[0029] Infrared heating can also improve the adsorption capacity of infrared spectroscopy molecular sieve adsorbents by directly acting on them. Infrared radiation may cause the pore structure of the molecular sieve to be more open, thereby increasing its specific surface area and adsorption sites. In addition, infrared radiation may also excite the active sites or groups on the surface of the molecular sieve, thereby enhancing the interaction between it and the target substance (i.e., the activated high-energy arsenic-containing complex). This enhanced interaction not only improves the adsorption efficiency of the adsorbent, but also accelerates the kinetics of the adsorption process.

[0030] 2. Compared with the traditional extraction method, resin method and phosphating method, the present process can remove arsenic in the copper sulfate solution more deeply. The activated high-energy arsenic-containing complex generated in the plasma electrolysis treatment step and the infrared spectrum molecular sieve adsorbent in the infrared adsorption purification treatment step can efficiently remove arsenic in complex forms such as arsenate and arsenite. Therefore, the present process can effectively solve the problem that the arsenic in the copper sulfate solution is complex and difficult to remove and purify deeply, and ensure that a feed-grade copper sulfate solution with a low arsenic content is obtained.

[0031] 3. The various steps of this process are closely connected, easy to operate, and easy to realize industrial production. At the same time, by adding chemical agents such as oxidants and solutions containing trivalent iron, and using physical methods such as plasma electrolysis and infrared heating, efficient removal of arsenic is achieved, avoiding the problem of introducing other impurities. In addition, the liquid level sensor and temperature sensor in the plasma generator can monitor the liquid level and temperature in the device in real time, ensuring that the treatment process is carried out under safe and stable conditions, thereby improving the safety and reliability of the process. DETAILED DESCRIPTION

[0032] The present application is further described in detail below with reference to the embodiments.

[0033] The composition of the PCB etching waste liquid used in the examples of this application is shown in Table 1:

[0034] Table 1 PCB etching waste liquid composition

[0035]

[0036] Example

[0037] Example 1

[0038] A feed-grade copper sulfate arsenic removal treatment process comprises the following steps:

[0039] S1. Oxidation treatment: Add 3% H2O2 as an oxidant to the PCB etching waste liquid, continue stirring under stirring conditions until the waste liquid becomes clear and transparent, stop stirring, and let it stand for 3 hours to obtain a coarse etching waste liquid.

[0040] S2. pH adjustment treatment: under stirring conditions, add Fe(OH)3 to the rough etching waste liquid, add 3kg of Fe(OH)3 powder to every cubic meter of waste liquid, and continue stirring until the mixture is evenly mixed.

[0041] S3, plasma electrolysis treatment: the waste liquid with pH adjusted passes through the plasma generator to ensure that the waste liquid flows in the direction of the electric field parallel to the plasma generating electrode. Under the action of plasma, the arsenate and arsenite particles in the waste liquid are activated and converted into activated high-energy arsenic-containing complexes, such as AsO4 -NO3, AsO3-NO2.

[0042] S4. Infrared adsorption purification treatment: The waste liquid treated by plasma electrolysis is passed through an infrared heating device with an infrared light wavelength of 5000nm for 30 minutes. Then, 13X molecular sieve is added as an infrared spectrum molecular sieve adsorbent under infrared irradiation conditions to adsorb and activate high-energy arsenic-containing complexes, and then filtered to obtain a copper sulfate solution.

[0043] Example 2

[0044] A feed-grade copper sulfate arsenic removal treatment process comprises the following steps:

[0045] S1. Oxidation treatment: Add 2% potassium permanganate as an oxidant to the PCB etching waste liquid, continue stirring under stirring conditions until the waste liquid becomes clear and transparent, stop stirring, and let it stand for 3 hours to obtain a coarse etching waste liquid.

[0046] S2. pH adjustment treatment: Under stirring conditions, add Fe(OH)3 to the rough etching waste liquid, add 2.5 kg of Fe(OH)3 powder to each cubic meter of waste liquid, and continue stirring until the mixture is evenly mixed.

[0047] S3, plasma electrolysis treatment: the waste liquid with pH adjusted passes through the plasma generator to ensure that the waste liquid flows in the direction of the electric field parallel to the plasma generating electrode. Under the action of plasma, the arsenate and arsenite particles in the waste liquid are activated and converted into activated high-energy arsenic-containing complexes, such as AsO 4 -NO3, AsO3-NO2.

[0048] S4. Infrared adsorption purification treatment: The waste liquid treated by plasma electrolysis is passed through an infrared heating device with an infrared light wavelength of 2500nm for 50 minutes. Then, 4A molecular sieve is added as an infrared spectrum molecular sieve adsorbent under infrared irradiation conditions to adsorb and activate high-energy arsenic-containing complexes, and then filtered to obtain a copper sulfate solution.

[0049] Example 3

[0050] A feed-grade copper sulfate arsenic removal treatment process comprises the following steps:

[0051] S1. Oxidation treatment: add 3% manganese dioxide as an oxidant to the PCB etching waste liquid, continue stirring under stirring conditions until the waste liquid becomes clear and transparent, stop stirring, and let it stand for 3 hours to obtain a coarse etching waste liquid.

[0052] S2. pH adjustment treatment: under stirring conditions, add Fe(OH)3 to the rough etching waste liquid, add 4 kg of Fe(OH)3 powder to each cubic meter of waste liquid, and continue stirring until the mixture is evenly mixed.

[0053] S3, plasma electrolysis treatment: the waste liquid with pH adjusted passes through the plasma generator to ensure that the waste liquid flows in the direction of the electric field parallel to the plasma generating electrode. Under the action of plasma, the arsenate and arsenite particles in the waste liquid are activated and converted into activated high-energy arsenic-containing complexes, such as AsO 4 -NO3, AsO3-NO2.

[0054] S4. Infrared adsorption purification treatment: The waste liquid treated by plasma electrolysis is passed through an infrared heating device with an infrared light wavelength of 10,000 nm for 20 minutes. Then, 4A molecular sieve is added as an infrared spectrum molecular sieve adsorbent under infrared irradiation conditions to adsorb and activate high-energy arsenic-containing complexes, and then filtered to obtain a copper sulfate solution.

[0055] Example 4

[0056] A feed-grade copper sulfate arsenic removal treatment process, which differs from Example 1 in that activated carbon is used as the adsorbent.

[0057] Example 5

[0058] A feed-grade copper sulfate arsenic removal treatment process, which differs from Example 1 in that sodium hypochlorite is used as an oxidant.

[0059] Comparative Example

[0060] Comparative Example 1

[0061] A feed-grade copper sulfate arsenic removal process, using a traditional extraction method, includes the following steps:

[0062] S1. Raw materials and pretreatment: PCB etching waste liquid is used as the starting raw material.

[0063] S2. Extraction process: an organic solvent is selected as the extractant, and the extraction operation is performed according to a conventional ratio (such as a liquid-liquid ratio of 1:2) at room temperature for 2 hours.

[0064] S3. The organic phase after extraction is separated, concentrated and other steps to obtain a copper sulfate solution.

[0065] Comparative Example 2

[0066] A feed-grade copper sulfate arsenic removal treatment process is different from Example 1 in that: in step S4, no infrared heating treatment is performed, and 13X molecular sieve is directly added as an infrared spectrum molecular sieve adsorbent to obtain a copper sulfate solution after adsorption and filtration.

[0067] Comparative Example 3

[0068] A feed-grade copper sulfate arsenic removal treatment process is different from Example 1 in that: no S3 plasma electrolysis treatment operation is performed, and the waste liquid after the pH adjustment treatment is directly subjected to infrared adsorption purification treatment to obtain a copper sulfate solution.

[0069] Performance testing

[0070] The components of the copper sulfate solutions obtained in Examples 1-5 and Comparative Examples 1-3 were detected, and the results are shown in Table 2.

[0071] Table 2 Detection results of copper sulfate solution components

[0072]

[0073]

[0074] Embodiments 1, 2, 3 and 5 respectively use different oxidants (H2O2, potassium permanganate, manganese dioxide and sodium hypochlorite). From the results, although these oxidants can effectively reduce the arsenic content in the copper sulfate solution, the effects are slightly different. Among them, the arsenic removal effect using H2O2 (Example 1) and manganese dioxide (Example 3) is better, probably because they have stronger oxidation ability for organic matter and other reducing substances in the waste liquid, which helps to release arsenic from complex compounds and facilitates subsequent treatment. In Examples 1 and 2, the addition amount of Fe(OH)3 is 3kg and 2.5kg per cubic meter of waste liquid, respectively. Although the addition amount is different, the arsenic removal effects of the two embodiments are similar, both between 0.22-0.23mg / L. This shows that within a certain range, the addition amount of Fe(OH)3 has little effect on the arsenic removal effect, but too little addition amount may not be enough to fully adjust the pH of the waste liquid, affecting the subsequent treatment effect.

[0075] Examples 1, 2 and 3 all include a plasma electrolysis treatment step, while Comparative Example 3 omits this step. From the results, the arsenic removal effect (0.20-0.23 mg / L) of the examples subjected to plasma electrolysis treatment is significantly better than that of Comparative Example 3 (5.59 mg / L) without such treatment. This indicates that plasma electrolysis treatment plays a key role in reducing the arsenic content in the copper sulfate solution, and provides more favorable conditions for subsequent infrared adsorption purification treatment by activating and converting arsenate and arsenite.

[0076] Examples 1, 2 and 3 all use infrared heating treatment and infrared spectrum molecular sieve adsorbent (13X molecular sieve or 4A molecular sieve) for adsorption purification. From the results, these steps have played a significant role in the arsenic removal effect. Among them, Example 1 (using 13X molecular sieve and 5000nm infrared light wavelength) has the best arsenic removal effect (0.22mg / L). Comparative Example 2 omits infrared heating treatment, and its arsenic removal effect (3.82mg / L) is poor, indicating that infrared heating treatment is crucial to improving the adsorption efficiency and arsenic removal effect of the adsorbent.

[0077] Comparative Example 1 uses the traditional extraction method. Although copper sulfate solution can be obtained, the arsenic content is high, and the operation is complicated and the cost is high. Comparative Example 2 omits the infrared heating treatment step. Although it still has a certain arsenic removal effect, it is not as ideal as the effect in Examples 1-3. Comparative Example 3 does not perform plasma electrolysis treatment, and the arsenic removal effect is also poor, indicating that plasma electrolysis treatment also plays an important role in reducing the arsenic content.

[0078] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A feed-grade copper sulfate arsenic removal process, characterized in that: The feed-grade copper sulfate arsenic removal treatment process comprises oxidation treatment, pH adjustment treatment, plasma electrolysis treatment and infrared adsorption purification treatment of PCB etching waste liquid in sequence; In the plasma electrolysis treatment step, the PCB etching waste liquid that has been treated with pH adjustment passes through the plasma generating device along the electric field direction parallel to the plasma generating electrode of the plasma generating device, so that the PCB etching waste liquid generates a plasma that is electrically neutral as a whole and includes electrons, positive ions, neutral particles, and free radicals; and the surfaces of arsenate and arsenite particles in the PCB etching waste liquid are charged; the plasma reacts with the arsenate and arsenite particles with charged surfaces in the PCB etching waste liquid to generate a catalytic activated high-energy arsenic-containing complex; In the infrared adsorption purification treatment step, the PCB etching waste liquid treated in the plasma electrolysis treatment step is heated by an infrared heating device, and the infrared light wavelength range of the infrared heating device during heating is 2500-10000nm, so that the activated high-energy arsenic-containing complex in the PCB etching waste liquid absorbs infrared energy and further reacts with the plasma remaining in the PCB etching waste liquid, and then an infrared spectrum molecular sieve adsorbent is added to adsorb and precipitate the activated high-energy arsenic-containing complex, and then filtered to obtain a copper sulfate solution.

2. The process for removing arsenic from feed-grade copper sulfate according to claim 1, characterized in that: In the infrared adsorption purification step, the infrared spectrum molecular sieve adsorbent is selected from 13X molecular sieve or 4A molecular sieve.

3. The process for removing arsenic from feed-grade copper sulfate according to claim 2, characterized in that: The infrared heating device comprises an infrared emitter and a liquid containing cavity. A plurality of columns are arranged in the liquid containing cavity. The plurality of columns enable the liquid to flow in an S shape.

4. The process for removing arsenic from feed-grade copper sulfate according to claim 1, characterized in that: The oxidation treatment comprises: adding an oxidant to the PCB etching waste liquid under stirring conditions until the PCB etching waste liquid becomes clear and transparent, and then standing for 2-4 hours to obtain a coarse etching waste liquid.

5. The process for removing arsenic from feed-grade copper sulfate according to claim 4, characterized in that: The oxidant includes any one of H2O2, potassium permanganate and manganese dioxide.

6. The process for removing arsenic from feed-grade copper sulfate according to claim 1, characterized in that: The pH adjustment treatment comprises: adding a solution containing trivalent iron to the rough etching waste liquid under stirring conditions, the amount of which is: 2-4 kg Fe per cubic meter of the rough etching waste liquid. 3+ .

7. The process for removing arsenic from feed-grade copper sulfate according to claim 1, characterized in that: The plasma generating device further comprises a liquid level sensor and a temperature sensor, and the liquid level sensor and the temperature sensor are used for real-time monitoring of the liquid level and temperature in the plasma generating device.

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