A method for treating mineral processing wastewater by electrocatalytic oxidation

Abstract

The present invention relates to the technical field of wastewater treatment, and specifically to a method for treating mineral processing wastewater by electrocatalytic oxidation. A particle electrode, an anode, and a cathode together construct a three-dimensional electrolysis system to electrocatalytically oxidize the mineral processing wastewater. The particle electrode comprises nitrogen-sulfur co-doped carbon aerogel and perovskite oxide. The present invention loads the perovskite oxide on the nitrogen-sulfur co-doped carbon aerogel to achieve a combination of the functions of the two, thereby achieving a better treatment effect on the mineral processing wastewater.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, in particular to a method for treating mineral processing wastewater through electrocatalytic oxidation. Background Art

[0002] The lead-zinc beneficiation process generally adopts the process flow of "lead priority flotation - lead concentrate ore regrinding - tailings activation zinc selection - zinc coarse concentrate regrinding". The generated beneficiation tail water contains residual ethylthiocyanate, butyl xanthate, pine oil, sulfide, etc., resulting in high COD value and metal ion content of the beneficiation wastewater. If it is discharged directly without treatment, it will cause environmental pollution of surrounding water bodies and endanger the ecological environment and human health. If it is directly reused, the residual beneficiation agents and activated metal ions in the wastewater will affect the lead and zinc separation indicators.

[0003] The three-dimensional electrolysis method is an advanced oxidation method that fills a traditional two-dimensional electrolytic cell with conductive particles as particle electrodes, causing pollutants to react on the surface of the particle electrodes. This method has the advantages of high degradation efficiency, simple operation, and green environmental protection. However, this technology has not been applied to mineral processing wastewater so far, and existing particle electrodes generally have the problem of low catalytic performance. Summary of the Invention

[0004] Purpose of the invention: In response to the above technical problems, the present invention proposes a method for treating mineral processing wastewater by electrocatalytic oxidation.

[0005] The technical solutions adopted are as follows:

[0006] A method for treating mineral processing wastewater by electrocatalytic oxidation:

[0007] The particle electrode, anode and cathode together form a three-dimensional electrolysis system to perform electrocatalytic oxidation treatment on mineral processing wastewater;

[0008] The particle electrode comprises nitrogen-sulfur co-doped carbon aerogel and perovskite oxide.

[0009] Furthermore, the perovskite oxide is Ag x La 1-x MO3;

[0010] 0<x≤0.1;

[0011] M is any one of Mn, Fe, Co, and Ni, or a combination of two or more thereof.

[0012] Furthermore, the preparation method of the nitrogen-sulfur co-doped carbon aerogel is as follows:

[0013] Formaldehyde, resorcinol, hexadecyltrimethylammonium bromide and deionized water are mixed and added to peanut oil, and the mixture is subjected to suspension polymerization reaction at 80-90°C for 5-10 days, and then filtered to obtain an organic wet gel. The organic wet gel is aged in deionized water for 5-10 days, washed, and then freeze-dried at low temperature to obtain an organic xerogel. The organic xerogel, ammonium thiocyanate and deionized water are mixed and subjected to hydrothermal reaction at 160-180°C for 5-10 hours, then taken out, washed, and freeze-dried again at low temperature to obtain a nitrogen-sulfur co-doped organic xerogel. Finally, the nitrogen-sulfur co-doped organic xerogel is calcined at 800-1000°C for 1-3 hours under nitrogen protection.

[0014] Furthermore, the mass ratio of the organic xerogel to ammonium thiocyanate is 1:50-100.

[0015] Further, x=0.02.

[0016] Furthermore, the preparation method of the particle electrode is as follows:

[0017] Ag salt, La salt, M salt and citric acid are dissolved in deionized water, nitrogen-sulfur co-doped carbon aerogel and polyethylene glycol are added and mixed, the pH of the solution is adjusted to 7-8 with ammonia water, the obtained mixed solution is stirred at 60-80°C for 1-10 hours and then dried and dehydrated to obtain a precursor, and the precursor is ground and calcined at 600-800°C for 5-10 hours.

[0018] Furthermore, the anode is a titanium-based ruthenium oxide coating anode.

[0019] Furthermore, the anode is mainly any one of RuO2 / Ti, RuO2-TiO2 / Ti, RuO2-SnO2-TiO2 / Ti and RuO2-Ta2O5 / Ti.

[0020] Furthermore, the cathode is a stainless steel electrode.

[0021] Furthermore, the dosage of the particle electrode in the mineral processing wastewater is 10-100 g / L.

[0022] Furthermore, the current density during electrocatalytic oxidation treatment is 40-60 mA / cm 2 .

[0023] Beneficial effects of the present invention:

[0024] The present invention provides a method for treating mineral processing wastewater through electrocatalytic oxidation. A combination of nitrogen-sulfur co-doped carbon aerogel and perovskite oxide is used as a particle electrode. Under the action of an external electric field, the particle electrode is induced to become charged and repolarized, so that the two ends of the particle are induced to act as an anode and a cathode, respectively, allowing the entire particle to form an independent microelectrode. Furthermore, the particle and the surrounding solution form multiple microelectrolytic cells. These microelectrolytic cells generate a large number of free radicals, catalytically degrade organic pollutants, and dissociate heavy metal ions.

[0025] Carbon aerogel has a large surface area and good adsorption capacity. After nitrogen and sulfur co-doping, nitrogen-containing groups such as graphitic nitrogen, pyridinic nitrogen and pyrrolic nitrogen are introduced to increase the active sites and form an electron-rich region with high spin density to regulate the local charge, thereby improving sp 2 The reaction activity of hybrid carbon can improve the electrochemical activity of carbon aerogel, but the catalytic oxidation effect of carbon material itself is weak. The metal ion at the B position of perovskite oxide has catalytic activity, and loading it on it can realize the combination of the two functions. The doping of Ag ions at the A position of perovskite oxide may not only produce oxygen vacancies but also change and adjust the valence state of the cation at the B position, thereby improving the electrochemical activity of perovskite oxide while improving the conductivity, thereby achieving better treatment effect on mineral processing wastewater. DETAILED DESCRIPTION

[0026] Unless otherwise specified, the following examples and comparative examples were conducted in parallel, using the same processing steps and parameters.

[0027] Example 1:

[0028] A method for treating mineral processing wastewater by electrocatalytic oxidation:

[0029] The lead-zinc tailings overflow water and the tailings pond intercepted seepage water were mixed in a ratio of 1:1. After standing for 10 hours, the clear liquid was taken as the mineral processing wastewater sample. The water quality of the mineral processing wastewater sample is shown in Table 1 below:

[0030] Table 1:

[0031]

[0032] The above-mentioned mineral processing wastewater is added to a cylindrical three-dimensional electrode reactor. The reactor is made of organic glass with a diameter of 40 mm, a height of 100 mm, and a wall thickness of 3 mm. The anode plate uses RuO2-TiO2 / Ti electrode, and the cathode uses a stainless steel plate. The distance between the anode and the cathode is 4 cm, and they are placed vertically in the reactor. There is an aeration device at the bottom of the reactor. The particle electrodes filled between the cathode and the anode are allowed to flow freely through aeration. In order to reduce the adsorption effect of the particle electrodes on the mineral processing wastewater during the reaction process, before the start of the electrocatalytic oxidation treatment, the particle electrodes are immersed in the mineral processing wastewater for 10 hours until the adsorption is saturated. The dosage of the particle electrodes is 10 g / L. At the beginning of the electrocatalytic oxidation treatment, the aeration volume is adjusted to 50 ml / min and the current intensity is 50 mA / cm 2 The electrocatalytic oxidation treatment time was 60 minutes. After 60 minutes, the water quality changes were analyzed by sampling and testing. The results are shown in Table 2 below:

[0033] Table 2:

[0034]

[0035] Among them, the particle electrode is composed of nitrogen and sulfur co-doped carbon aerogel and Ag 0.02 La 0.98 The preparation method of the particle electrode is as follows:

[0036] 6 g formaldehyde, 11 g resorcinol, 1 g hexadecyltrimethylammonium bromide and 100 ml deionized water were mixed and added to 500 ml peanut oil. After suspension polymerization at 80 ° C for 7 days, the organic wet gel was filtered to obtain the organic wet gel. The organic wet gel was aged in 500 ml deionized water for 7 days and then fully washed with anhydrous ethanol and deionized water. Then, it was freeze-dried at low temperature to obtain the organic dry gel. The organic dry gel and ammonium thiocyanate with a mass ratio of 1:60 were mixed and added to deionized water with a solid-liquid mass ratio of 1:10. After the hydrothermal reaction was sealed at 170 ° C for 7 hours, it was restored to room temperature, the precipitate was collected and fully washed with anhydrous ethanol and deionized water, and then The nitrogen-sulfur co-doped organic xerogel was obtained by secondary low-temperature freeze drying, and finally the nitrogen-sulfur co-doped organic xerogel was placed in a muffle furnace and calcined at 900°C for 2h under nitrogen protection to obtain nitrogen-sulfur co-doped carbon aerogel. 3.4mg of silver nitrate, 319mg of lanthanum nitrate, 179mg of manganese nitrate and 384mg of citric acid were dissolved in 50ml of deionized water, 5g of nitrogen-sulfur co-doped carbon aerogel and 35mg of polyethylene glycol 200 were added and mixed, and the pH of the solution was adjusted to 8 with ammonia water. The obtained mixed solution was stirred at 70°C for 5h and then heated to 100°C for drying and dehydration to obtain a precursor. The precursor was ground into powder and calcined at 700°C for 5h.

[0037] Example 2:

[0038] The same as Example 1, except that the particle electrode is made of nitrogen-sulfur co-doped carbon aerogel and Ag 0.02 La 0.98 The preparation method of the particle electrode is as follows:

[0039] 6 g formaldehyde, 11 g resorcinol, 1 g hexadecyltrimethylammonium bromide and 100 ml deionized water were mixed and added to 500 ml peanut oil. After suspension polymerization at 80 ° C for 7 days, the organic wet gel was filtered to obtain the organic wet gel. The organic wet gel was aged in 500 ml deionized water for 7 days and then fully washed with anhydrous ethanol and deionized water. Then, it was freeze-dried at low temperature to obtain the organic dry gel. The organic dry gel and ammonium thiocyanate with a mass ratio of 1:60 were mixed and added to deionized water with a solid-liquid mass ratio of 1:10. After the hydrothermal reaction was sealed at 170 ° C for 7 hours, it was restored to room temperature, the precipitate was collected and fully washed with anhydrous ethanol and deionized water, and then The nitrogen-sulfur co-doped organic xerogel was obtained by secondary low-temperature freeze drying, and finally the nitrogen-sulfur co-doped organic xerogel was placed in a muffle furnace and calcined at 900°C for 2h under nitrogen protection to obtain nitrogen-sulfur co-doped carbon aerogel. 3.4mg of silver nitrate, 319mg of lanthanum nitrate, 242mg of ferric nitrate and 384mg of citric acid were dissolved in 50ml of deionized water, 5g of nitrogen-sulfur co-doped carbon aerogel and 35mg of polyethylene glycol 200 were added and mixed, and the pH of the solution was adjusted to 8 with ammonia water. The obtained mixed solution was stirred at 70°C for 5h and then heated to 100°C for drying and dehydration to obtain a precursor. The precursor was ground into powder and calcined at 700°C for 5h.

[0040] The electrocatalytic oxidation treatment time was 60 minutes. After 60 minutes, the water quality changes were analyzed by sampling and testing. The results are shown in Table 3 below:

[0041] Table 3:

[0042]

[0043] Example 3:

[0044] The same as Example 1, except that the particle electrode is made of nitrogen-sulfur co-doped carbon aerogel and Ag 0.02 La 0.98 The preparation method of the particle electrode is as follows:

[0045] 6 g formaldehyde, 11 g resorcinol, 1 g hexadecyltrimethylammonium bromide and 100 ml deionized water were mixed and added to 500 ml peanut oil. After suspension polymerization at 80 ° C for 7 days, the organic wet gel was filtered to obtain the organic wet gel. The organic wet gel was aged in 500 ml deionized water for 7 days and then fully washed with anhydrous ethanol and deionized water. Then, it was freeze-dried at low temperature to obtain the organic dry gel. The organic dry gel and ammonium thiocyanate with a mass ratio of 1:60 were mixed and added to deionized water with a solid-liquid mass ratio of 1:10. After the hydrothermal reaction was sealed at 170 ° C for 7 hours, it was restored to room temperature, the precipitate was collected and fully washed with anhydrous ethanol and deionized water, and then The nitrogen-sulfur co-doped organic xerogel was obtained by secondary low-temperature freeze drying, and finally the nitrogen-sulfur co-doped organic xerogel was placed in a muffle furnace and calcined at 900°C for 2h under nitrogen protection to obtain nitrogen-sulfur co-doped carbon aerogel. 3.4mg of silver nitrate, 319mg of lanthanum nitrate, 183mg of cobalt nitrate and 384mg of citric acid were dissolved in 50ml of deionized water, 5g of nitrogen-sulfur co-doped carbon aerogel and 35mg of polyethylene glycol 200 were added and mixed, and the pH of the solution was adjusted to 8 with ammonia water. The obtained mixed solution was stirred at 70°C for 5h and then heated to 100°C for drying and dehydration to obtain a precursor. The precursor was ground into powder and calcined at 700°C for 5h.

[0046] The electrocatalytic oxidation treatment time was 60 minutes. After 60 minutes, the water quality changes were analyzed by sampling and testing. The results are shown in Table 4 below:

[0047] Table 4:

[0048]

[0049] Example 4:

[0050] The same as Example 1, except that the particle electrode is made of nitrogen-sulfur co-doped carbon aerogel and Ag 0.02 La 0.98 The preparation method of the particle electrode is as follows:

[0051] 6 g formaldehyde, 11 g resorcinol, 1 g hexadecyltrimethylammonium bromide and 100 ml deionized water were mixed and added to 500 ml peanut oil. After suspension polymerization at 80 ° C for 7 days, the organic wet gel was filtered to obtain the organic wet gel. The organic wet gel was aged in 500 ml deionized water for 7 days and then fully washed with anhydrous ethanol and deionized water. Then, it was freeze-dried at low temperature to obtain the organic dry gel. The organic dry gel and ammonium thiocyanate with a mass ratio of 1:60 were mixed and added to deionized water with a solid-liquid mass ratio of 1:10. After the hydrothermal reaction was sealed at 170 ° C for 7 hours, it was restored to room temperature, the precipitate was collected and fully washed with anhydrous ethanol and deionized water, and then The nitrogen-sulfur co-doped organic xerogel was obtained by secondary low-temperature freeze drying, and finally the nitrogen-sulfur co-doped organic xerogel was placed in a muffle furnace and calcined at 900°C for 2h under nitrogen protection to obtain nitrogen-sulfur co-doped carbon aerogel. 3.4mg of silver nitrate, 319mg of lanthanum nitrate, 183mg of nickel nitrate and 384mg of citric acid were dissolved in 50ml of deionized water, 5g of nitrogen-sulfur co-doped carbon aerogel and 35mg of polyethylene glycol 200 were added and mixed, and the pH of the solution was adjusted to 8 with ammonia water. The obtained mixed solution was stirred at 70°C for 5h and then heated to 100°C for drying and dehydration to obtain a precursor. The precursor was ground into powder and calcined at 700°C for 5h.

[0052] The electrocatalytic oxidation treatment time was 60 minutes. After 60 minutes, the water quality changes were analyzed by sampling and testing. The results are shown in Table 5 below:

[0053] Table 5:

[0054]

[0055] Comparative Example 1:

[0056] The method is basically the same as Example 1, except that carbon aerogel is used as the particle electrode;

[0057] The preparation method of carbon aerogel is as follows:

[0058] 6 g of formaldehyde, 11 g of resorcinol, 1 g of hexadecyltrimethylammonium bromide and 100 ml of deionized water were mixed and added to 500 ml of peanut oil. The mixture was suspended and polymerized at 80°C for 7 days and then filtered to obtain an organic wet gel. The organic wet gel was aged in 500 ml of deionized water for 7 days and then thoroughly washed with anhydrous ethanol and deionized water. The organic dry gel was then freeze-dried at low temperature to obtain an organic dry gel. The organic dry gel was placed in a muffle furnace and calcined at 900°C for 2 hours under nitrogen protection.

[0059] The electrocatalytic oxidation treatment time was 60 minutes. After 60 minutes, the water quality changes were analyzed by sampling and testing. The results are shown in Table 6 below:

[0060] Table 6:

[0061]

[0062] By comparing with Example 1, it can be seen that the treatment effect of using carbon aerogel as particle electrode on mineral processing wastewater is far inferior to that of using nitrogen-sulfur co-doped carbon aerogel and Ag 0.02 La 0.98 The particle electrode composed of MnO3 has a good treatment effect on mineral processing wastewater.

[0063] Comparative Example 2:

[0064] The method is basically the same as Example 1, except that nitrogen-sulfur co-doped carbon aerogel is used as the particle electrode. The preparation method of nitrogen-sulfur co-doped carbon aerogel is as follows:

[0065] 6 g formaldehyde, 11 g resorcinol, 1 g hexadecyltrimethylammonium bromide and 100 ml deionized water were mixed and added to 500 ml peanut oil. The mixture was suspended and polymerized at 80°C for 7 days and then filtered to obtain an organic wet gel. The organic wet gel was aged in 500 ml deionized water for 7 days and then thoroughly washed with anhydrous ethanol and deionized water. The organic xerogel was then freeze-dried to obtain an organic xerogel. The organic xerogel and ammonium thiocyanate at a mass ratio of 1:60 were mixed and added to deionized water at a solid-liquid mass ratio of 1:10. The mixture was sealed and hydrothermally reacted at 170°C for 7 hours. The mixture was then returned to room temperature. The precipitate was collected and thoroughly washed with anhydrous ethanol and deionized water. The nitrogen-sulfur co-doped organic xerogel was finally calcined at 900°C for 2 hours in a muffle furnace under nitrogen protection to obtain a nitrogen-sulfur co-doped carbon aerogel.

[0066] The electrocatalytic oxidation treatment time was 60 minutes. After 60 minutes, the water quality changes were analyzed by sampling and testing. The results are shown in Table 7 below:

[0067] Table 7:

[0068]

[0069] By comparing with Example 1 and Comparative Example 1, it can be seen that the treatment effect of using nitrogen-sulfur co-doped carbon aerogel as particle electrode on mineral processing wastewater is not as good as that of using nitrogen-sulfur co-doped carbon aerogel and Ag 0.02 La 0.98 The particle electrode composed of MnO3 has a good treatment effect on mineral processing wastewater, but is better than the treatment effect of using carbon aerogel as a particle electrode on mineral processing wastewater.

[0070] Comparative Example 3:

[0071] It is basically the same as Example 1, except that Ag is used 0.02 La 0.98 MnO3 as particle electrode;

[0072] Ag 0.02 La0.98 The preparation method of MnO3 is as follows:

[0073] Dissolve 3.4 mg of silver nitrate, 319 mg of lanthanum nitrate, 179 mg of manganese nitrate and 384 mg of citric acid in 50 ml of deionized water, add 35 mg of polyethylene glycol 200 and mix well, adjust the pH of the solution to 8 with ammonia water, stir the obtained mixed solution at 70 ° C for 5 hours, then heat it to 100 ° C for drying and dehydration to obtain a precursor, grind the precursor into powder and calcine it at 700 ° C for 5 hours.

[0074] The electrocatalytic oxidation treatment time was 60 minutes. After 60 minutes, the water quality changes were analyzed by sampling and testing. The results are shown in Table 8 below:

[0075] Table 8:

[0076]

[0077] By comparison with Example 1, it can be seen that the use of Ag alone 0.02 La 0.98 The treatment effect of MnO3 as particle electrode on mineral processing wastewater is not as good as that of nitrogen-sulfur co-doped carbon aerogel and Ag. 0.02 La 0.98 The particle electrode composed of MnO3 has a good treatment effect on mineral processing wastewater.

[0078] Comparative Example 4:

[0079] The method is basically the same as Example 1, except that the particle electrode is composed of nitrogen-sulfur co-doped carbon aerogel and LaMnO3. The preparation method of the particle electrode is as follows:

[0080] 6g formaldehyde, 11g resorcinol, 1g hexadecyltrimethylammonium bromide and 100ml deionized water were mixed and added to 500ml peanut oil. After suspension polymerization at 80℃ for 7d, the organic wet gel was filtered to obtain the organic dry gel. The organic wet gel was aged in 500ml deionized water for 7d and then fully washed with anhydrous ethanol and deionized water. Then, the organic dry gel was freeze-dried at low temperature to obtain the organic dry gel. The organic dry gel and ammonium thiocyanate with a mass ratio of 1:60 were mixed and added to deionized water with a solid-liquid mass ratio of 1:10. After the reaction was sealed and hydrothermally reacted at 170℃ for 7h, the reaction was restored to room temperature, the precipitate was collected and filled with anhydrous ethanol and deionized water. The obtained mixture was washed separately and freeze-dried again at low temperature to obtain nitrogen-sulfur co-doped organic xerogel. Finally, the nitrogen-sulfur co-doped organic xerogel was placed in a muffle furnace and calcined at 900°C for 2h under nitrogen protection to obtain nitrogen-sulfur co-doped carbon aerogel. 325mg of lanthanum nitrate, 179mg of manganese nitrate and 384mg of citric acid were dissolved in 50ml of deionized water, 5g of nitrogen-sulfur co-doped carbon aerogel and 35mg of polyethylene glycol 200 were added and mixed, and the pH of the solution was adjusted to 8 with ammonia water. The obtained mixed solution was stirred at 70°C for 5h and then heated to 100°C for drying and dehydration to obtain a precursor. The precursor was ground into powder and calcined at 700°C for 5h.

[0081] The electrocatalytic oxidation treatment time was 60 minutes. After 60 minutes, the water quality changes were analyzed by sampling and testing. The results are shown in Table 9 below:

[0082] Table 9:

[0083]

[0084] By comparison with Example 1, it can be seen that the nitrogen-sulfur co-doped carbon aerogel and Ag 0.02 La 0.98 The particle electrode composed of Ag and LaMnO3 has a better treatment effect on mineral processing wastewater than the particle electrode composed of nitrogen-sulfur co-doped carbon aerogel and LaMnO3, indicating that Ag doping plays a positive role in improving the treatment effect.

[0085] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for treating mineral processing wastewater by electrocatalytic oxidation, characterized in that: The particle electrode, anode and cathode together form a three-dimensional electrolysis system to perform electrocatalytic oxidation treatment on mineral processing wastewater; The particle electrode comprises nitrogen-sulfur co-doped carbon aerogel and perovskite oxide; The perovskite oxide is Ag x La 1-x MO3; x=0.02； M is any one of Mn, Fe, Co, and Ni, or a combination of two or more; The preparation method of the nitrogen-sulfur co-doped carbon aerogel is as follows: Formaldehyde, resorcinol, hexadecyltrimethylammonium bromide and deionized water are mixed and added to peanut oil, and the mixture is subjected to suspension polymerization reaction at 80-90°C for 5-10 days, followed by filtration to obtain an organic wet gel. The organic wet gel is aged in deionized water for 5-10 days, washed, and then freeze-dried to obtain an organic xerogel. The organic xerogel, ammonium thiocyanate and deionized water are mixed and subjected to hydrothermal reaction at 160-180°C for 5-10 hours, taken out, washed, and freeze-dried again to obtain a nitrogen-sulfur co-doped organic xerogel. Finally, the nitrogen-sulfur co-doped organic xerogel is calcined at 800-1000°C under nitrogen protection for 1-3 hours. The anode is a titanium-based ruthenium oxide coating anode; The cathode is a stainless steel electrode.

2. The method for treating mineral processing wastewater by electrocatalytic oxidation according to claim 1, wherein: The mass ratio of the organic xerogel to ammonium thiocyanate is 1:50-100.

3. The method for treating mineral processing wastewater by electrocatalytic oxidation according to claim 1, wherein: The preparation method of the particle electrode is as follows: Ag salt, La salt, M salt and citric acid are dissolved in deionized water, nitrogen-sulfur co-doped carbon aerogel and polyethylene glycol are added and mixed, the pH of the solution is adjusted to 7-8 with ammonia water, the obtained mixed solution is stirred at 60-80°C for 1-10 hours and then dried and dehydrated to obtain a precursor, and the precursor is ground and calcined at 600-800°C for 5-10 hours.

4. The method for treating mineral processing wastewater by electrocatalytic oxidation according to claim 1, wherein: The dosage of particle electrode is 10-100g / L.

5. The method for treating mineral processing wastewater by electrocatalytic oxidation according to claim 1, wherein: The current density during electrocatalytic oxidation treatment is 40-60 mA / cm 2 .

Images