Method for preparing iron-manganese-based photocatalytic material through alkaline leaching of wolframite, iron-manganese-based photocatalytic material and application of iron-manganese-based photocatalytic material

Abstract

The invention relates to a method for preparing an iron-manganese-based photocatalytic material through alkaline leaching of wolframite, the iron-manganese-based photocatalytic material and application of the iron-manganese-based photocatalytic material, and belongs to the technical field of sewage treatment. The preparation method comprises the following steps: carrying out pressurized alkaline leaching on wolframite concentrate, carrying out solid-liquid separation, taking solids, and carrying out drying treatment to obtain the iron-manganese-based photocatalytic material. And the ratio of the amount of substance of Fe to the amount of substance of Mn in the wolframite concentrate is adjusted to be 1.8-2.3: 1. A traditional wolframite leaching process does not have economical application to leaching residues after leaching, and the iron-manganese-based photocatalytic material prepared by adjusting the ratio of the amount of substance of Fe to the amount of substance of Mn in wolframite concentrate and then carrying out pressurized alkaline leaching can not only degrade mine organic wastewater, but also purify the organic wastewater; the influence of the organic wastewater of the mine on the ecological environment of the mine is reduced, the alkaline leaching residues obtained by alkaline leaching of the wolframite concentrate can be well applied, the stockpiling and discharging cost of the alkaline leaching residues and the treatment cost of the organic wastewater are reduced, and the cost benefit is achieved.

Description

Technical Field

[0001] This invention relates to a method for preparing iron-manganese-based photocatalytic materials by alkaline leaching of wolframite, the iron-manganese-based photocatalytic materials and their applications, and belongs to the field of wastewater treatment technology. Background Technology

[0002] Flotation is one of the mainstream technologies in mining production. To improve the hydrophobic properties of minerals in the slurry and enhance their floatability, large amounts of organic flotation reagents are often added during the flotation process, resulting in a large amount of organic mineral processing wastewater. However, these reagents (such as xanthates and black reagents) contain halogenated hydrocarbons, which are recalcitrant organic compounds with bioaccumulation properties. If the wastewater is discharged or reused without treatment, it will accumulate in the mining ecosystem. Over time, this will pose a significant threat to the health of residents around the mine and damage the mine's aquatic ecosystem. Therefore, the treatment and control of organic wastewater pollution from mines is of paramount importance.

[0003] Extensive technical research has been conducted to address this issue, with common treatment methods including: coagulation-flocculation, adsorption, Fenton oxidation, ozone oxidation, photocatalytic oxidation, and persulfate catalytic oxidation. However, these technologies for treating organic wastewater from mines have significant limitations: coagulation-flocculation is easy to operate and has low cost, but it has poor adaptability to mine wastewater and residual chemical flocculants can easily cause secondary wastewater pollution; adsorption can efficiently adsorb organic mineral processing reagents, but it has high treatment costs and challenges such as low adsorption capacity and adsorbent regeneration; Fenton oxidation is limited by the pH range of the catalytic reaction, and the transportation and storage of Fenton reagents have high costs and safety risks, as well as the generation of large amounts of iron slag; ozone oxidation has high production costs due to low ozone utilization; and persulfate catalytic oxidation is a relatively recent development and is still in the research stage, not yet widely applied.

[0004] Photocatalytic oxidation technology is currently considered one of the most promising technologies for the degradation of organic wastewater from mines. However, most classic photocatalysts (such as TiO2 and ZnO) can only respond to ultraviolet light due to their wide bandgap. When using sunlight as a light source, they can only utilize 5% of the ultraviolet light in the solar spectrum, resulting in low light energy utilization efficiency and high production costs. These shortcomings limit their application in industry.

[0005] Therefore, developing a novel photocatalytic material that is low-cost, easy to prepare, and has a strong visible light response to achieve the effective degradation of organic wastewater from mines is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] To address the problems existing in the prior art, one of the objectives of this invention is to provide a method for preparing iron-manganese-based photocatalytic materials by alkaline leaching of wolframite. This invention adjusts the molar ratio of Fe and Mn in wolframite concentrate before pressure alkaline leaching, and the resulting iron-manganese-based photocatalytic material has photocatalytic properties. Moreover, the preparation method is simple.

[0007] The second objective of this invention is to provide an iron-manganese-based photocatalytic material.

[0008] The third objective of this invention is to provide a method for degrading mine organic wastewater using an iron-manganese-based photocatalytic material. This method utilizes the iron-manganese-based photocatalytic material provided by this invention to degrade mine organic wastewater in the presence of visible light. The treatment method is simple, suitable for industrial application, and provides a new solution for mine organic wastewater treatment. It not only degrades mine organic wastewater, reducing its impact on the mine's ecological environment and protecting the mine's ecology, thus contributing to the construction of green mines, but also allows for the effective application of the products obtained from alkaline leaching of tungsten concentrate. This reduces the costs of stockpiling and discharging tungsten concentrate leaching residue and the cost of treating organic wastewater, demonstrating cost-effectiveness.

[0009] To achieve the above objectives, a first aspect of the present invention provides a method for preparing iron-manganese-based photocatalytic materials by alkaline leaching of wolframite, the method comprising:

[0010] Wolf tungsten concentrate was subjected to pressure alkaline leaching, and after solid-liquid separation, the solid was dried to obtain iron-manganese-based photocatalytic materials.

[0011] The molar ratio of Fe to Mn in wollastonite concentrate can be adjusted to 1.8~2.3:1 by adding iron or manganese supplements.

[0012] Wolframite is rich in Fe and Mn elements. The large amount of iron-manganese slag produced after leaching tungsten using traditional processes is often treated as solid waste or stockpiled, with little research on its comprehensive resource utilization. Currently, the mainstream applications of wolframite alkaline leaching slag include: reduction smelting of Fe-Mn alloys, silicon extraction for silica synthesis, arsenic removal and curing for building materials, and manganese extraction for high-purity manganese sulfate reagent. Based on the excellent photocatalytic characteristics of iron-manganese-based materials, such as synergistic electron transfer, complementary energy level matching, and functionalized structural design, the applicant is exploring leaching processes for wolframite. This invention first adjusts the molar ratio of Fe to Mn in the wolframite concentrate, and then performs pressurized alkaline leaching of the concentrate. This ensures that the prepared iron-manganese-based photocatalytic material has the optimal phase for photocatalytic degradation (iron-manganese spinel phase). When the Fe or Mn content in the wolframite concentrate is too high, the phase of the iron-manganese-based photocatalytic material will transform into mainly amorphous iron oxides or manganese oxides, reducing the optimal phase content and decreasing photocatalytic performance.

[0013] It should be noted that when the molar ratio of Fe to Mn in wolframite concentrate is 1.8 to 2.3:1, there is no need to add iron or manganese supplements.

[0014] As a preferred embodiment, the WO3 content in the wolframite concentrate is ≥65wt%.

[0015] It should be noted that the present invention does not have special requirements for the source of wolframite concentrate, which can be obtained by a combination of processes such as flotation, gravity separation, magnetic separation, and photoelectric separation.

[0016] As a preferred option, the wolframite concentrate is first crushed to a particle size of no more than 200 mesh before pressure alkali leaching.

[0017] As a preferred embodiment, the iron supplement is an iron oxide, and the manganese supplement is a manganese oxide and / or a manganese oxyacid salt.

[0018] As a preferred embodiment, the iron oxide is selected from at least one of ferrous oxide, iron oxide, and iron spinel.

[0019] As a preferred embodiment, the manganese supplement is selected from at least one of manganese sulfate, manganese oxide, manganese trioxide, manganese dioxide, potassium manganate, and potassium permanganate.

[0020] As a preferred embodiment, the pressure alkaline leaching temperature is 180~240℃ and the time is 1~6h.

[0021] It should be noted that the present invention does not have any special requirements for the pressure of the pressurized alkali leaching; any pressure known in the art can be used.

[0022] As a preferred embodiment, the pressurized alkali leaching is carried out under stirring conditions, with a stirring rate of 200~400 rpm.

[0023] As a preferred embodiment, the alkaline solution used in the pressurized alkaline leaching is a sodium hydroxide solution and / or a potassium hydroxide solution, and the ratio of the total amount of sodium hydroxide and potassium hydroxide to the amount of WO3 in the wolframite concentrate is 2-3:1. Under these preferred conditions, a greater amount of WO3 is dissolved from the wolframite, essentially all of it.

[0024] As a preferred embodiment, the liquid-to-solid ratio of the alkaline solution to the wolframite concentrate is 3-6:1 ml / g.

[0025] As a preferred embodiment, an oxidant is added during pressurized alkaline leaching, wherein the amount of oxidant is 8-12 wt% of the mass of the wolframite concentrate. The oxidant can accelerate leaching, remove sulfide mineral impurities, improve the purity of the iron-manganese-based photocatalytic material, and thus increase the degradation rate of organic wastewater.

[0026] As a preferred embodiment, the oxidant is selected from at least one of hydrogen peroxide, sodium persulfate, and sodium hypochlorite.

[0027] As a preferred approach, the solid obtained after drying is subjected to magnetic separation or alkaline leaching to remove silicon, yielding an iron-manganese-based photocatalytic material. Silicon removal improves the purity of the iron-manganese-based photocatalytic material, thereby increasing its degradation rate for organic wastewater.

[0028] As a preferred embodiment, the magnetic field strength for the magnetic separation of silicon is 0.1~0.4T.

[0029] As a preferred embodiment, the alkaline leaching method for removing silicon includes: leaching the dried solid in a 4-8 mol / L sodium hydroxide solution and / or potassium hydroxide solution for 1-3 hours, at a leaching temperature of 80-100℃, a liquid-to-solid ratio of 5-10:1 ml / g, and a leaching stirring speed of 200-400 rpm.

[0030] A second aspect of the present invention is to provide an iron-manganese-based photocatalytic material prepared by the preparation method described in the first aspect above.

[0031] A third aspect of the present invention is to provide a method for degrading mine organic wastewater with an iron-manganese-based photocatalytic material, the method comprising: mixing the mine organic wastewater with the iron-manganese-based photocatalytic material for photocatalytic degradation in the presence of an oxygen-containing stream and visible light;

[0032] The iron-manganese-based photocatalytic material is the iron-manganese-based photocatalytic material described in the second aspect above.

[0033] In the presence of visible light and with the introduction of an oxygen-containing flow, photocatalytic degradation can be carried out continuously, realizing the "oxidation-reduction" cycle on the catalyst surface. If no oxygen-containing flow is introduced, the iron-manganese-based photocatalytic material will lose some of its activity after degrading organic matter in mine wastewater, resulting in a significant decrease in degradation capacity.

[0034] As a preferred embodiment, the mine organic wastewater contains at least one organic pollutant selected from butyl xanthate, sodium oleate, and kerosene, and the concentration of the organic pollutant in the mine organic wastewater is 50-70 ppm.

[0035] As a preferred embodiment, during photocatalytic degradation, an aeration pump is used to introduce air at a flow rate of 0.8~1.2 L / min.

[0036] As a preferred embodiment, the wavelength of the visible light is greater than 380 nm and less than 1200 nm.

[0037] As a preferred embodiment, the photocatalytic degradation time is 2-5 hours.

[0038] As a preferred embodiment, the pH of the mine organic wastewater is 9-9.5. If the mine wastewater is acidic, the iron-manganese-based photocatalyst will undergo hydrolysis; if the mine organic wastewater is too alkaline, the surface active sites of the iron-manganese-based photocatalyst will be passivated, and the organic pollutant molecules in the mine organic wastewater will be deprotonated, thus inhibiting the adsorption performance.

[0039] This invention does not have any special requirements for the solid-liquid ratio of mine organic wastewater and iron-manganese-based photocatalytic materials; any known ratio in the art can be used.

[0040] Compared with the prior art, the present invention has at least the following advantages:

[0041] This invention uses alkaline leaching residue from wolframite concentrate as a novel photocatalytic mineral material, providing a new solution for the treatment of mine organic wastewater. It can not only reduce the impact of mine organic wastewater on the mine's ecological environment, but also make good use of wolframite alkaline leaching residue, reducing the cost of stockpiling and discharging wolframite alkaline leaching residue and the cost of treating organic wastewater, thus achieving cost-effectiveness.

[0042] The iron-manganese-based photocatalytic material of this invention treats simulated organic wastewater in a green, environmentally friendly, and sustainable manner, achieving a removal rate of over 90% for simulated mine organic wastewater, thus realizing the effective degradation of mine organic wastewater. Furthermore, the preparation method of the iron-manganese-based photocatalytic material of this invention is simple, economical in cost, and produces no secondary pollution. It can also dispose of tailings from wolframite leaching, effectively achieving the goal of protecting the mine ecosystem and building green mines. Attached Figure Description

[0043] Figure 1 These are the XRD patterns of iron-manganese-based photocatalysts 1, 2, and 3. The figures show that the main phases in iron-manganese-based photocatalyst 1 are siliceous minerals, scheelite, and some weaker iron-manganese spinel phases. Although the leaching residue contains a large amount of iron and manganese, its crystal structure is poor, and no diffraction peaks appear. Therefore, its degradation ability for organic wastewater is weaker than that of iron-manganese-based photocatalysts 2 and 3. When the scheelite leaching residue is subjected to magnetic separation / alkali leaching to remove silicon, the diffraction peaks of siliceous minerals in the XRD patterns of iron-manganese-based photocatalysts 2 and 3 weaken, while the diffraction peaks of the iron-manganese spinel phase strengthen, becoming the main phase of the material and further increasing its photocatalytic performance. Detailed Implementation

[0044] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0045] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments. Obviously, the embodiments described below are only a part of the embodiments, and all other embodiments obtained by those skilled in the art without creative effort are still within the scope of protection of the present invention.

[0046] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0047] The embodiments of the present invention are used to prepare iron-manganese-based photocatalytic materials.

[0048] Example 1

[0049] The composition of wolframite concentrate is as follows: WO3 content is 67.91wt%, Fe content is 12.66wt%, and Mn content is 5.78wt%.

[0050] The wolframite concentrate obtained by gravity-flotation combined separation was crushed and ground to a particle size of -200 mesh. The leaching feedstock n(TFe):n(Mn) = 2.155:1 was used to leach the feedstock by pressurized alkaline leaching. The leaching experimental conditions were: n(NaOH):n(WO3) = 2:1, leaching temperature 200℃, leaching liquid-solid ratio 3:1 ml / g, leaching time 1.5h, leaching stirring speed 300rpm, and pressure 2MPa. No oxidant was added during pressurized alkaline leaching. After filtration, washing and drying, iron-manganese based photocatalytic material 1 was obtained.

[0051] Example 2

[0052] The composition of wolframite concentrate is as follows: WO3 content is 65.86wt%, Fe content is 7.91wt%, and Mn content is 8.62wt%.

[0053] (1) The wolframite concentrate obtained by photoelectric separation-gravity separation-magnetic separation-flotation combined separation was crushed and ground to a particle size of -400 mesh. Iron oxide was used as an iron supplement to control the leaching raw material n(TFe):n(Mn)=2:1. The leaching raw material was leached by pressure alkaline leaching. The leaching experimental conditions were: n(NaOH):n(WO3)=3:1, leaching temperature 220℃, leaching liquid-solid ratio 4:1ml / g, leaching time 4h, leaching stirring speed 300rpm, pressure 2.31MPa. Sodium persulfate was added as an oxidant during pressure alkaline leaching, and the amount was 10wt% of the amount of wolframite concentrate. After filtration, washing and drying, solid matter was obtained.

[0054] (2) Then, the solid obtained in step (1) is subjected to magnetic separation to remove silicon. The magnetic field strength is 0.1T to obtain iron-manganese-based photocatalytic material 2.

[0055] Example 3

[0056] The composition of wolframite concentrate is as follows: WO3 content is 69.34wt%, Fe content is 3.17wt%, and Mn content is 11.49wt%.

[0057] (1) The wolframite concentrate obtained by gravity separation-magnetic separation-flotation combined separation was crushed and ground to a particle size of -325 mesh. Iron oxide was used as an iron supplement to control the leaching raw material n(TFe):n(Mn)=2:1. The leaching raw material was leached by pressure alkaline leaching. The leaching experimental conditions were: n(NaOH):n(WO3)=2.5:1, leaching temperature 210℃, leaching liquid-solid ratio 6:1ml / g, leaching time 6h, leaching stirring speed 300rpm, pressure 2.3MPa. During pressure alkaline leaching, hydrogen peroxide (mass concentration of hydrogen peroxide is 10wt%) was added as an oxidant, and the amount was 10wt% of the amount of wolframite concentrate. After filtration, washing and drying, solid matter was obtained.

[0058] (2) The solid obtained in step (1) was subjected to atmospheric pressure leaching under the experimental conditions of sodium hydroxide concentration of 8 mol / L, leaching temperature of 100℃, leaching liquid-solid ratio of 10:1 ml / g, leaching time of 2h, and leaching stirring speed of 300 rpm. After filtration, washing and drying, iron-manganese-based photocatalytic material 3 was obtained.

[0059] Example 4

[0060] This embodiment is carried out using a method similar to that of Example 3, except that the amount of iron oxide is adjusted to control the leaching raw material n(TFe):n(Mn) = 2.2:1, thus obtaining iron-manganese based photocatalytic material 4.

[0061] Example 5

[0062] This embodiment is carried out in a similar manner to that of embodiment 3, except that step (2) is not performed, and the solid obtained in step (1) is used as the iron-manganese-based photocatalytic material 5.

[0063] Example 6

[0064] This embodiment is carried out using a method similar to that of Embodiment 3, except that no oxidant is added in step (1) to obtain iron-manganese-based photocatalytic material 6.

[0065] Comparative Example 1

[0066] This comparative example was carried out using a method similar to that of Example 3, except that iron oxide was added as an iron supplement, and the raw material n(TFe):n(Mn) was leached with a ratio of 4:1 to obtain iron-manganese-based photocatalyst material D1.

[0067] Comparative Example 2

[0068] This comparative example was conducted using a method similar to that of Example 3, except that no iron supplement was added, and the leaching raw material n(TFe):n(Mn) = 0.27:1, yielding iron-manganese-based photocatalyst material D2.

[0069] Application Example 1

[0070] In this application example, the organic wastewater from mineral processing was simulated using butyl xanthate, with a concentration of 60 ppm and a pH of 9.3.

[0071] Application Example 1-1: Take 100 mL of mineral processing organic wastewater, weigh 200 mg of the iron-manganese-based photocatalytic material prepared in the above example, and place it in a 150 mL volume photocatalytic reactor. The photocatalytic reactor is darkly adsorbed at a speed of 300 rpm. Air is continuously introduced into the photocatalytic reactor using an aeration pump at a gas flow rate of 1 L / min. After 2 hours, the final simulated degradation rate of mineral processing organic wastewater is 50.42%.

[0072] Application Example 1-2: Take 100 mL of mineral processing organic wastewater, weigh 200 mg of the iron-manganese-based photocatalytic material prepared in the above example, and place it in a 150 mL photocatalytic reactor. Then, place the reactor under a 500 W xenon lamp (>380 nm) for irradiation. Use an aeration pump to continuously introduce air into the photocatalytic reactor at a gas flow rate of 1 L / min. After 2 hours of photocatalysis, the final simulated degradation rate of the mineral processing organic wastewater is as follows:

[0073] The iron-manganese-based photocatalytic material 1 prepared in Example 1 achieved a degradation rate of 85.97% for mineral processing organic wastewater.

[0074] The iron-manganese-based photocatalytic material 2 prepared in Example 2 achieved a degradation rate of 95.11% for mineral processing organic wastewater.

[0075] The iron-manganese-based photocatalytic material 3 prepared in Example 3 achieved a degradation rate of 96.97% for mineral processing organic wastewater.

[0076] The iron-manganese-based photocatalytic material 4 prepared in Example 4 achieved a degradation rate of 96.54% for mineral processing organic wastewater.

[0077] The iron-manganese-based photocatalytic material 5 prepared in Example 5 achieved a degradation rate of 85.28% for mineral processing organic wastewater.

[0078] The iron-manganese-based photocatalytic material 6 prepared in Example 6 achieved a degradation rate of 95.83% for mineral processing organic wastewater.

[0079] The iron-manganese-based photocatalyst D1 prepared in Comparative Example 1 achieved a degradation rate of 59.16% for organic wastewater from mineral processing.

[0080] The iron-manganese-based photocatalyst D2 prepared in Comparative Example 2 had a degradation rate of 62.88% for mineral processing organic wastewater.

[0081] Application Example 1-3: This application example follows a similar method to Application Example 1-2, except that the photocatalytic time is adjusted to 5 hours. The final simulated degradation rate of organic wastewater from mineral processing is as follows:

[0082] The iron-manganese-based photocatalytic material 1 prepared in Example 1 achieved a degradation rate of 91.86% for mineral processing organic wastewater.

[0083] The iron-manganese-based photocatalytic material 2 prepared in Example 2 achieved a degradation rate of 95.78% for mineral processing organic wastewater.

[0084] The iron-manganese-based photocatalytic material 3 prepared in Example 3 achieved a degradation rate of 97.83% for mineral processing organic wastewater.

[0085] The iron-manganese-based photocatalytic material 4 prepared in Example 4 achieved a degradation rate of 96.61% for mineral processing organic wastewater.

[0086] The iron-manganese-based photocatalytic material 5 prepared in Example 5 achieved a degradation rate of 91.90% for organic wastewater from mineral processing.

[0087] The iron-manganese-based photocatalytic material 6 prepared in Example 6 achieved a degradation rate of 96.15% for mineral processing organic wastewater.

[0088] The iron-manganese-based photocatalyst D1 prepared in Comparative Example 1 achieved a degradation rate of 80.38% for organic wastewater from mineral processing.

[0089] The iron-manganese-based photocatalyst D2 prepared in Comparative Example 2 had a degradation rate of 85.12% for mineral processing organic wastewater.

[0090] Application Example 2

[0091] In this application example, the organic wastewater from mineral processing was simulated using sodium oleate, with a sodium oleate concentration of 60 ppm and a pH of 9.4.

[0092] Application Example 2-1: Take 100 mL of mineral processing organic wastewater, weigh 200 mg of the iron-manganese-based photocatalytic material 2 prepared in Example 2, and place it in a 150 mL volume photocatalytic reactor. The photocatalytic reactor is darkly adsorbed at a speed of 300 rpm. Air is continuously introduced into the photocatalytic reactor using an aeration pump at a gas flow rate of 1 L / min. After 2 hours, the final degradation rate of the simulated mineral processing organic wastewater is 47.62%.

[0093] Application Example 2-2: Take 100 mL of mineral processing organic wastewater, weigh 200 mg of the iron-manganese-based photocatalytic material prepared in the above example, and place it in a 150 mL photocatalytic reactor. Then, place the reactor under a 500 W xenon lamp (>380 nm) for irradiation. Use an aeration pump to continuously introduce air into the photocatalytic reactor at a gas flow rate of 1 L / min. After 2 hours of photocatalysis, the final simulated degradation rate of the mineral processing organic wastewater is as follows:

[0094] The iron-manganese-based photocatalytic material 1 prepared in Example 1 achieved a degradation rate of 84.25% for mineral processing organic wastewater.

[0095] The iron-manganese-based photocatalytic material 2 prepared in Example 2 achieved a degradation rate of 94.42% for mineral processing organic wastewater.

[0096] The iron-manganese-based photocatalytic material 3 prepared in Example 3 achieved a degradation rate of 96.29% for mineral processing organic wastewater.

[0097] The iron-manganese-based photocatalytic material 4 prepared in Example 4 achieved a degradation rate of 95.33% for mineral processing organic wastewater.

[0098] The iron-manganese-based photocatalytic material 5 prepared in Example 5 achieved a degradation rate of 83.66% for mineral processing organic wastewater.

[0099] The iron-manganese-based photocatalytic material 6 prepared in Example 6 achieved a degradation rate of 96.03% for mineral processing organic wastewater.

[0100] The iron-manganese-based photocatalyst D1 prepared in Comparative Example 1 achieved a degradation rate of 50.34% for organic wastewater from mineral processing.

[0101] The iron-manganese-based photocatalyst D2 prepared in Comparative Example 2 had a degradation rate of 55.87% for mineral processing organic wastewater.

[0102] Application Example 2-3: This application example follows a similar method to Application Example 2-2, except that the photocatalytic time is adjusted to 5 hours. The final simulated degradation rate of organic wastewater from mineral processing is as follows:

[0103] The iron-manganese-based photocatalytic material 1 prepared in Example 1 achieved a degradation rate of 90.95% for mineral processing organic wastewater.

[0104] The iron-manganese-based photocatalytic material 2 prepared in Example 2 achieved a degradation rate of 95.51% for mineral processing organic wastewater.

[0105] The iron-manganese-based photocatalytic material 3 prepared in Example 3 achieved a degradation rate of 97.43% for mineral processing organic wastewater.

[0106] The iron-manganese-based photocatalytic material 4 prepared in Example 4 achieved a degradation rate of 96.15% for mineral processing organic wastewater.

[0107] The iron-manganese-based photocatalytic material 5 prepared in Example 5 achieved a degradation rate of 91.04% for mineral processing organic wastewater.

[0108] The iron-manganese-based photocatalytic material 6 prepared in Example 6 achieved a degradation rate of 96.76% for mineral processing organic wastewater.

[0109] The iron-manganese-based photocatalyst D1 prepared in Comparative Example 1 achieved a degradation rate of 78.59% for organic wastewater from mineral processing.

[0110] The iron-manganese-based photocatalyst D2 prepared in Comparative Example 2 had a degradation rate of 85.49% for organic wastewater from mineral processing.

[0111] Application Example 3

[0112] In this application example, the organic wastewater from mineral processing was simulated using kerosene, with a kerosene concentration of 60 ppm and a pH of 9.2.

[0113] Application Example 3-1: Take 100 mL of mineral processing organic wastewater, weigh 200 mg of the iron-manganese-based photocatalytic material 3 prepared in Example 3, and place it in a 150 mL volume photocatalytic reactor. The photocatalytic reactor is darkly adsorbed at a speed of 300 rpm. Air is continuously introduced into the photocatalytic reactor using an aeration pump at a gas flow rate of 1 L / min. After 2 hours, the final simulated degradation rate of mineral processing organic wastewater is 49.11%.

[0114] Application Example 3-2: Take 100 mL of mineral processing organic wastewater, weigh 200 mg of the iron-manganese-based photocatalytic material prepared in the above example, and place it in a 150 mL photocatalytic reactor. Then, place the reactor under a 500 W xenon lamp (>380 nm) for irradiation. Use an aeration pump to continuously introduce air into the photocatalytic reactor at a gas flow rate of 1 L / min. After 2 hours of photocatalysis, the final simulated degradation rate of the mineral processing organic wastewater is as follows:

[0115] The iron-manganese-based photocatalytic material 1 prepared in Example 1 achieved a degradation rate of 84.67% for mineral processing organic wastewater.

[0116] The iron-manganese-based photocatalytic material 2 prepared in Example 2 achieved a degradation rate of 95.01% for mineral processing organic wastewater.

[0117] The iron-manganese-based photocatalytic material 3 prepared in Example 3 achieved a degradation rate of 96.66% for mineral processing organic wastewater.

[0118] The iron-manganese-based photocatalytic material 4 prepared in Example 4 achieved a degradation rate of 95.24% for mineral processing organic wastewater.

[0119] The iron-manganese-based photocatalytic material 5 prepared in Example 5 achieved a degradation rate of 84.10% for mineral processing organic wastewater.

[0120] The iron-manganese-based photocatalytic material 6 prepared in Example 6 achieved a degradation rate of 96.64% for mineral processing organic wastewater.

[0121] The iron-manganese-based photocatalyst D1 prepared in Comparative Example 1 achieved a degradation rate of 52.49% for organic wastewater from mineral processing.

[0122] The iron-manganese-based photocatalyst D2 prepared in Comparative Example 2 had a degradation rate of 58.16% for organic wastewater from mineral processing.

[0123] Application Example 3-3: This application example follows a similar method to Application Example 3-2, except that the photocatalytic time is adjusted to 5 hours. The final simulated degradation rate of organic wastewater from mineral processing is as follows:

[0124] The iron-manganese-based photocatalytic material 1 prepared in Example 1 achieved a degradation rate of 91.91% for mineral processing organic wastewater.

[0125] The iron-manganese-based photocatalytic material 2 prepared in Example 2 achieved a degradation rate of 95.82% for mineral processing organic wastewater.

[0126] The iron-manganese-based photocatalytic material 3 prepared in Example 3 achieved a degradation rate of 97.13% for organic wastewater from mineral processing.

[0127] The iron-manganese-based photocatalytic material 4 prepared in Example 4 achieved a degradation rate of 96.54% for mineral processing organic wastewater.

[0128] The iron-manganese-based photocatalytic material 5 prepared in Example 5 achieved a degradation rate of 91.33% for mineral processing organic wastewater.

[0129] The iron-manganese-based photocatalytic material 6 prepared in Example 6 achieved a degradation rate of 96.55% for mineral processing organic wastewater.

[0130] The iron-manganese-based photocatalyst D1 prepared in Comparative Example 1 achieved a degradation rate of 80.08% for organic wastewater from mineral processing.

[0131] The iron-manganese-based photocatalyst D2 prepared in Comparative Example 2 had a degradation rate of 86.31% for mineral processing organic wastewater.

[0132] Application Example 4

[0133] In this application example, the organic wastewater from mineral processing was simulated using kerosene, with a kerosene concentration of 60 ppm and a pH of 9.2.

[0134] Take 100 mL of mineral processing organic wastewater, weigh 200 mg of the iron-manganese-based photocatalytic material prepared in the above example, and place it in a 150 mL photocatalytic reactor. Then, place the reactor under irradiation with a 500 W xenon lamp (>380 nm), and continuously introduce nitrogen gas into the reactor using an aeration pump at a flow rate of 0.8-1.2 L / min. After 5 hours of photocatalysis, the final simulated degradation rate of the mineral processing organic wastewater is as follows:

[0135] The iron-manganese-based photocatalytic material 1 prepared in Example 1 achieved a degradation rate of 68.88% for mineral processing organic wastewater.

[0136] The iron-manganese-based photocatalytic material 2 prepared in Example 2 achieved a degradation rate of 72.34% for mineral processing organic wastewater.

[0137] The iron-manganese-based photocatalytic material 3 prepared in Example 3 had a degradation rate of 74.98% on mineral processing organic wastewater.

[0138] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing iron-manganese-based photocatalytic materials by alkaline leaching of wolframite, characterized in that: The method includes: Wolf tungsten concentrate was subjected to pressure alkaline leaching, and after solid-liquid separation, the solid was dried to obtain iron-manganese-based photocatalytic materials. The molar ratio of Fe to Mn in wollastonite concentrate can be adjusted to 1.8~2.3:1 by adding iron or manganese supplements.

2. The method for preparing iron-manganese-based photocatalytic materials by alkaline leaching of wolframite according to claim 1, characterized in that: The WO3 content in the wolframite concentrate is ≥65wt%; And / or, the iron supplement is an iron oxide, and the manganese supplement is a manganese oxide and / or a manganese oxyacid salt.

3. The method for preparing iron-manganese-based photocatalytic materials by alkaline leaching of wolframite according to claim 1 or 2, characterized in that: The pressure alkaline leaching is carried out at a temperature of 180~240℃ for 1~6 hours. And / or, the alkaline solution used in the pressurized alkaline leaching is a sodium hydroxide solution and / or a potassium hydroxide solution, and the ratio of the total amount of sodium hydroxide and potassium hydroxide to the amount of WO3 in the wolframite concentrate is 2~3:

1.

4. The method for preparing iron-manganese-based photocatalytic materials by alkaline leaching of wolframite according to claim 3, characterized in that: The liquid-to-solid ratio of the alkaline solution to the wolframite concentrate is 3~6:1 ml / g.

5. A method for preparing iron-manganese-based photocatalytic materials by alkaline leaching of wolframite according to claim 1 or 2, characterized in that: An oxidant is added during pressurized alkaline leaching, and the amount of the oxidant is 8-12 wt% of the mass of the wolframite concentrate.

6. A method for preparing iron-manganese-based photocatalytic materials by alkaline leaching of wolframite according to claim 1 or 2, characterized in that: The solid obtained after drying is subjected to magnetic separation or alkaline leaching to remove silicon, thus obtaining iron-manganese-based photocatalytic materials.

7. The method for preparing iron-manganese-based photocatalytic materials by alkaline leaching of wolframite according to claim 6, characterized in that: The magnetic field strength for the magnetic separation and silicon removal is 0.1~0.4T; And / or, the alkaline leaching method for removing silicon includes: leaching the dried solid in a 4-8 mol / L sodium hydroxide solution and / or potassium hydroxide solution for 1-3 hours, at a leaching temperature of 80-100°C, a liquid-to-solid ratio of 5-10:1 ml / g, and a leaching stirring speed of 200-400 rpm.

8. The iron-manganese-based photocatalytic material prepared by the preparation method according to any one of claims 1 to 7.

9. A method for degrading mine organic wastewater using an iron-manganese-based photocatalytic material, characterized in that: The method includes: mixing mine organic wastewater with an iron-manganese-based photocatalytic material for photocatalytic degradation in the presence of an oxygen-containing flow and visible light; wherein the iron-manganese-based photocatalytic material is the iron-manganese-based photocatalytic material as described in claim 8.

10. A method for degrading mine organic wastewater using an iron-manganese-based photocatalytic material according to claim 9, characterized in that: The organic wastewater from the mine contains at least one organic pollutant selected from butyl xanthate, sodium oleate, and kerosene, and the concentration of the organic pollutant in the organic wastewater is 50-70 ppm. And / or, during photocatalytic degradation, an aeration pump is used to introduce air at a flow rate of 0.8~1.2 L / min.

Images