Humic acid / tourmaline composite material and preparation method and application thereof

Abstract

The present application provides a kind of humic acid / tourmaline composite material and its preparation method and application. By using improved method to pretreat humic acid, the most suitable proportion range of humic acid quality and solvent volume is explored to ensure the maximum dissolution and purification of humic acid. The improved loading ratio of humic acid on tourmaline makes the tourmaline particles fully contact with humic acid, and the reaction of tourmaline and humic acid produces directional intergrowth. Humic acid intergrowth adheres to the surface of tourmaline particles, and the structure of the prepared composite material is stable. Through adsorption, chemical precipitation and ion exchange, the removal efficiency of high concentration total iron ions in complex acid mine wastewater can be greatly improved. The removal rate of total iron ions can reach 98.5% within 30 minutes. At the same time, Fe 2+ Also has good removal effect. After adsorption reaction, the composite material has certain viscosity, good solid-liquid separation effect, and can be recycled and reused after desorption regeneration.

Description

Technical Field

[0001] The present invention belongs to the technical field of groundwater pollution remediation and treatment, and specifically relates to a humic acid / tourmaline composite material and a preparation method and application thereof. Background Art

[0002] Acid mine drainage (AMD) has a high content of heavy metal ions, is produced in large quantities and is continuously generated. Its disposal requires long-term investment. How to effectively, conveniently and cost-effectively treat Mine Drainage in the long term has become an urgent environmental issue. Acid mine drainage treatment methods are mainly divided into two categories: active treatment and passive treatment. Active treatment can effectively render acid mine drainage harmless, but the operating costs are high and it is unsustainable; passive treatment also has its own limitations: the pollutant removal efficiency is relatively low, the treatment cycle is long, and it is not suitable for large-volume wastewater. Adsorption technology stands out due to its high flexibility in operation and design, and this method has significant effects on toxicity, bioavailability and heavy metal removal in wastewater. How to find new materials or modify them to further reduce application costs and improve adsorption performance is a major challenge facing researchers.

[0003] Tourmaline possesses permanent, spontaneous electrode properties, generating an electric field that alters the equilibrium state of the hydrogen-bonded network of water clusters, making it suitable for catalytic degradation applications. However, the agglomeration of tourmaline powder particles prevents its excellent properties from being fully realized. Therefore, modifying tourmaline to improve its compatibility and dispersibility in composite materials has become a research hotspot.

[0004] Humic acid is a macromolecular organism widely found in nature. It has the advantages of being environmentally friendly, low cost, and having a high surface area and surface energy. It can react with Cu in the environment. 2+ 、Cd 2+ , Pb 2+ However, when humic acid is used for wastewater treatment and the pH value is greater than 2, HA will dissolve in the water, causing new water pollution. In addition, when used as a single adsorbent, the mechanical properties are low and the stability is poor.

[0005] The academic paper "Research on the Remediation of Iron-Manganese Contaminated Groundwater by Insoluble Humic Acid / Tourmaline Composite Particles" discloses a preparation method for insoluble humic acid / tourmaline composite particles: the pretreated HA is dissolved in 0.1 mol / L NaOH, and then tourmaline powder (TM) is added at a ratio of TM:HA=2:3, the pH is adjusted to 6.0, and then the mixture is placed in a shaker at 30°C and 150r / min to react for 18 hours, and the precipitate is collected and then washed with distilled water. The wet solid material is dried in an oven at 60-70°C, ground and sieved, and then etherified starch (1 / 10) gelatinized at 95°C is added and mixed to form adsorbent particles with a particle size of 3-5 mm. After calcination in a muffle furnace at 330°C for 90 minutes, insoluble humic acid / tourmaline composite particles are formed. The insoluble humic acid / tourmaline composite particles have a good effect on Fe 2+ The removal rate of Fe increased rapidly with the increase of pH, and in the treatment of 100mL simulated groundwater with pH 6.5 and Fe 2+ Content 25mg / L, Mn 2+ The optimal conditions for the composite water sample with a content of 10 mg / L were: TM / HA dosage 10 g / L, pH 6, reaction time 240 min, temperature 35 °C, rotation speed 150 r / min, Fe 2+ 、Mn 2+ The removal rates of humic acid and tourmaline are 99.98% and 99.65% respectively. However, the preparation method of the insoluble humic acid / tourmaline composite particles is complicated, the processing time is long, and it cannot treat groundwater in complex environments (such as acid mine wastewater, etc.).

[0006] Therefore, there is an urgent need to provide a method that is simple in process operation, low in cost, and can efficiently remove total iron ions in acidic mine wastewater. Summary of the Invention

[0007] The purpose of the present invention is to address the above-mentioned deficiencies in the prior art and to provide a humic acid / tourmaline composite material and a preparation method and application thereof.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] The first object of the present invention is to provide a method for preparing a humic acid / tourmaline composite material, comprising the following specific steps:

[0010] Step S1, dissolving humic acid in a 0.5-0.55 mol / L NaOH solution, then adjusting the pH to 0.9-1.1 with 10-12 mol / L hydrochloric acid to obtain a first solution, heating the first solution in a water bath at 60-65° C., cooling, centrifuging, and drying to obtain pretreated humic acid;

[0011] Step S2, dissolving the pretreated humic acid obtained in step S1 in a NaOH solution, then adding tourmaline in a tourmaline:humic acid mass ratio of 2:3 to 3:2, and then adding a hydrochloric acid solution, adjusting the pH value to 5.5 to 6.5, stirring and reacting at a constant temperature of 35 to 55° C. for 18 to 24 hours, and after the reactant is cooled, centrifuging, washing with water, and drying to obtain a humic acid / tourmaline composite material.

[0012] Furthermore, in step S1, the mass volume ratio of the humic acid to the NaOH solution is 1:(25-50).

[0013] Furthermore, the chemical formula of the tourmaline is NaFe3B3Al6Si6O 27 (OH)3F.

[0014] Furthermore, the particle size of the tourmaline is not greater than 325 mesh.

[0015] The second object of the present invention is to provide a humic acid / tourmaline composite material prepared by the above method.

[0016] Furthermore, the humic acid / tourmaline composite material is gray, and particles of the humic acid / tourmaline composite material exhibit a certain degree of stickiness.

[0017] The third object of the present invention is to provide the use of the humic acid / tourmaline composite material in the treatment of acidic mine wastewater.

[0018] Furthermore, the pH of the acid mine drainage water is less than 3, and the total iron ion concentration in the acid mine drainage water is not higher than 600 mg / L.

[0019] A fourth object of the present invention is to provide a method for removing iron ions from acidic mine wastewater using the humic acid / tourmaline composite material. The humic acid / tourmaline composite material is added to the acidic mine wastewater in an amount of 4 to 12 g / L.

[0020] A fifth object of the present invention is to provide a permeable reactive wall comprising the above-mentioned humic acid / tourmaline composite material.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The humic acid / tourmaline composite material provided by the present invention, and its preparation method and application. By adopting an improved method to pretreat humic acid, the optimal ratio range of the mass of humic acid and the volume of the solvent is explored to ensure the maximum dissolution and purification of humic acid; the loading ratio of humic acid on tourmaline is improved so that when the tourmaline particles are in full contact with the humic acid, the tourmaline and humic acid react to produce directional intergrowth, and the humic acid intergrowth is attached to the surface of the tourmaline particles, and the structure of the prepared composite material is stable. Through adsorption, chemical precipitation, and ion exchange, the removal efficiency of high-concentration total iron ions in complex acidic mine wastewater can be greatly improved. The removal rate of total iron ions can reach 98.5% within 30 minutes, and the material has a high efficiency in removing Fe 2+ It has a good removal effect and can remove Fe in simulated wastewater with a concentration of 200 mg / L within 120 minutes. 2+ Almost all of the substances are removed; and the composite material has a certain viscosity after the adsorption reaction, has a good solid-liquid separation effect, and can be recycled and reused after desorption and regeneration.

[0023] (2) The preparation method provided by the present invention is simple and low in cost. The prepared humic acid / tourmaline composite material is easy to use, requires a small amount of addition, has a high iron ion removal efficiency, and has good market value and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1a This is the result graph of total iron ion removal rate in acid mine drainage water with different tourmaline particle sizes;

[0025] Figure 1b This is a typical sampling area map of acid mine drainage;

[0026] Figure 2 This is a SEM image of the humic acid / tourmaline composite material prepared in Example 1;

[0027] Figure 3 This is the SEM image of the humic acid / tourmaline composite material after adsorbing iron ions;

[0028] Figure 4 This is a photo of the humic acid / tourmaline composite material after successful preparation and drying;

[0029] Figure 5 This is a photo of tourmaline powder material;

[0030] Figure 6 This is a photo of the material after humic acid / tourmaline composite material adsorbed iron ions in wastewater;

[0031] Figure 7 This is the XRD comparison diagram of tourmaline before and after loading humic acid;

[0032] Figure 8The figure is a comparison of the total iron ion removal rate of humic acid / tourmaline composite materials with different loading ratios;

[0033] Figure 9 The figure is a comparison of the total iron ion removal rate of humic acid / tourmaline composite materials at different loading times;

[0034] Figure 10 The figure is a comparison of the total iron ion removal rate of humic acid / tourmaline composite materials at different loading temperatures;

[0035] Figure 11 This is the experimental result diagram of different dosages of humic acid / tourmaline composite materials;

[0036] Figure 12 This is a comparison chart of the adsorption removal rate of iron ions in wastewater by unloaded original tourmaline and loaded composite materials;

[0037] Figure 13 This is a comparison chart of the removal rate of divalent iron ions in simulated wastewater with different concentrations by humic acid / tourmaline composite materials. DETAILED DESCRIPTION

[0038] To make the purpose, technical solutions and advantages of the present invention clearer, the specific embodiments of the present invention are described in further detail below in conjunction with specific examples and accompanying drawings. Where specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in this field or the product specifications are used. Where the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be obtained commercially.

[0039] The tourmaline used in this embodiment is iron tourmaline, and its chemical formula is NaFe3B3Al6Si6O 27 The chemical composition of (OH)3F, tourmaline is shown in Table 1.

[0040] Table 1.

[0041]

[0042] The purchased tourmaline raw stones were ground and mechanically crushed to obtain different particle sizes. Through experiments under different tourmaline particle size conditions, the optimal tourmaline particle size was determined. Figure 1a Analysis shows that the smaller the tourmaline particle size, the better the removal of target pollutants. When the tourmaline particle size is less than 325 mesh, it needs to be mechanically polished. Moreover, due to the spontaneous permanent polarization effect of tourmaline, if the particle size is too small, the particles will be suspended in the water, making solid-liquid separation difficult. Taking into account practical applications and solid-liquid separation performance, the optimal tourmaline particle size is 325 mesh.

[0043] Acid mine drainage sampling area:

[0044] The acid mine drainage water sample in the embodiment is mainly derived from the drainage of a typical abandoned pyrite mine and the groundwater and surface water formed after the precipitation leaching of the mine residue (or mine residue pile), and contains a large amount of iron ions. At present, typical pyrite mines have been closed, but the rock fissures caused by mining engineering cannot be restored to the natural state, and the left roadway has not been completely blocked, resulting in an increase in the amount of atmospheric precipitation infiltration, a change in the water circulation period, a significant strengthening of the reaction between the formed groundwater and the residual ore body in the rock, and the formation of strong acid water (pH < 2) rich in iron and sulfate ions, which is continuously discharged to the surface water through the roadway or fissure and pollutes the surface water. With the increase of the exposure time of the contaminated surface water and the increase of the pH (pH < 3), the dissolved iron ions are oxidized to form complexes and adhere to the river bottom sediments, which are brown-red, as shown in FIG. 1. Figure 1b

[0045] Embodiment 1

[0046] The preparation method of the humic acid / tourmaline composite material provided in the embodiment comprises the following steps:

[0047] (1) A proper amount of humic acid is dissolved in a 0.5 mol / L NaOH solution, and after stirring until completely dissolved, a 10 mol / L HCl solution is added to adjust the pH value to about 1.0, and the mass of the humic acid to the volume of the NaOH solution is 1: (25-50), wherein the unit of the mass of the humic acid is gram, and the unit of the volume of the NaOH and HCl solutions is milliliter. Water bath heating (60°C) is performed, and after cooling to room temperature, centrifugation and drying are performed to obtain the pretreated humic acid.

[0048] (2) The humic acid obtained in step (1) is dissolved in a NaOH solution, and after stirring until completely dissolved, a proper amount of tourmaline (325 mesh) is added, the mass ratio of the tourmaline to the humic acid is 3:2, and then an HCl solution is added to adjust the pH value to 6.0. The reaction is stirred in a magnetic stirrer at a constant temperature for 18 hours (rotation speed 600 r / min, temperature 45°C), and after the reaction is cooled, centrifugation (centrifugal speed 6000 r / min, centrifugal time 5 min), water washing and drying are performed to obtain the humic acid / tourmaline composite material.

[0049] Embodiment 2

[0050] The preparation method of the humic acid / tourmaline composite material provided in the embodiment comprises the following steps:

[0051] The preparation method of the humic acid / tourmaline composite material provided in the embodiment comprises the following steps:

[0052] Embodiment 3

[0053] The preparation method of the humic acid / tourmaline composite material provided in the embodiment comprises the following steps:​

[0054] The method is basically the same as Example 1, except that the mass ratio of tourmaline to humic acid is 3:1.

[0055] Example 4

[0056] The preparation method of the humic acid / tourmaline composite material provided in this embodiment comprises the following steps:

[0057] The process is basically the same as Example 1, except that the constant stirring temperature is 35°C.

[0058] Example 5

[0059] The preparation method of the humic acid / tourmaline composite material provided in this embodiment comprises the following steps:

[0060] The process is basically the same as Example 1, except that the constant stirring temperature is 55°C.

[0061] Example 6

[0062] The preparation method of the humic acid / tourmaline composite material provided in this embodiment comprises the following steps:

[0063] The process is basically the same as Example 1, except that the reaction time is 24 h under constant temperature stirring.

[0064] Comparative Example 1

[0065] Unloaded tourmaline.

[0066] Comparative Example 2

[0067] The preparation method of the humic acid / tourmaline composite material provided in this embodiment comprises the following steps:

[0068] The process is basically the same as Example 1, except that the reaction time under constant temperature stirring is 6 h.

[0069] Comparative Example 3

[0070] The preparation method of the humic acid / tourmaline composite material provided in this embodiment comprises the following steps:

[0071] The reaction was basically the same as in Example 1, except that the reaction time was 12 h under constant temperature stirring.

[0072] In order to better illustrate the performance and fluorine removal effect of the humic acid / tourmaline composite material prepared by the present invention, the applicant conducted the following research:

[0073] 1. Micromorphology characterization of humic acid / tourmaline composites

[0074] Characterization of humic acid / tourmaline composite materials: including SEM and XRD to characterize the morphology and crystal phase of the materials.

[0075] The humic acid / tourmaline composite materials prepared in Examples 1-6 have similar morphological structures. Figure 2 , which is the SEM image of the humic acid / tourmaline composite material prepared in Example 1. It can be seen that the humic acid is not simply adhered to the surface of the tourmaline particles, but is directional intergrowth. There are irregular flaky substances between the humic acid surface and the tourmaline surface that combine the two, with an amorphous layered structure. The larger porosity is conducive to the adsorption of metal substances.

[0076] refer to Figure 3 , is the SEM picture of the humic acid / tourmaline composite material after adsorbing iron ions. It can be seen that the surface structure morphology has changed significantly. Some cluster structures formed by large particles have been lost, and small particles have been formed. A covering layer of particulate matter has appeared, and a large number of fragments and small particles have been generated. This is because the functional groups on the surface of the humic acid / tourmaline adsorbent provide the necessary channels and space for the adsorption of iron ions, which is conducive to the adsorption of iron ions.

[0077] refer to Figure 4 , is the material after humic acid / tourmaline composite material is successfully prepared and dried. It can be seen that the color of the material is the same as tourmaline powder (such as Figure 5 Compared with the material shown in the figure, it has changed significantly and is gray. There is a certain viscosity between the material particles. This is the physical property of tourmaline loaded with humic acid after modification. It is also placed in pure water and evenly dispersed and allowed to stand. Due to the viscosity between the particles, the humic acid / tourmaline composite material settles to the bottom of the water and takes less time to separate from the water.

[0078] refer to Figure 6 , is the material after humic acid / tourmaline composite material adsorbs iron ions in wastewater. It can be seen that the color of the composite material after adsorption is the same as Figure 4 Compared with the original material, there has been a significant change, it is now khaki with a yellowish-brown color, and the viscosity between the material particles after adsorption is more obvious. This is because when the composite material adsorbs iron ions in the wastewater, the iron ions in the wastewater are adsorbed to the surface of the composite material particles through ion exchange, negative ion effect, electric field attraction and other reactions, forming a layer of film. This shows that the composite material is highly efficient in removing iron ions from wastewater.

[0079] refer to Figure 7 , is the XRD comparison diagram of tourmaline before and after loading humic acid. It can be seen from the figure that there are mainly several characteristic peaks at 26.65°, 29.52°, 31.005°, 41.145°, 44.928°, 51.064° and 59.826°. The above characteristic peaks are basically consistent with the standard peaks of TM. TM is composed of NaFe3B3Al6Si6O 27(OH)3F. The composite material's diffraction peaks appeared at 28.041° and 35.646°, respectively. Comparison of the diffraction peaks of tourmaline and the composite material revealed similarities. The changes in the diffraction peaks on the composite material's crystal surface coincided with the standard peaks of humic acid, indicating that humic acid was attached to the tourmaline surface and that the modified composite material was successfully prepared.

[0080] 2. Adsorption performance test of humic acid / tourmaline composite materials

[0081] Adsorption experiment: The total iron ion concentration in actual acidic mine drainage water is 400.5 mg / L and the pH is 2.48. Prepare 100 ml of actual acidic mine drainage water. Take an appropriate amount of humic acid / tourmaline composite material and place 100 ml of the wastewater into a 150 ml conical flask. Add the humic acid / tourmaline composite material to the wastewater. Stir the mixture on a thermostatic magnetic stirrer at 300 rpm at room temperature. Samples are taken at regular intervals, filtered through an aqueous filter membrane, and then the total iron content in the samples is determined using o-phenanthroline spectrophotometry.

[0082] refer to Figure 8 , which is a comparison chart of the total iron ion removal rate of humic acid / tourmaline composite materials with different loading ratios. It can be seen that the material with a tourmaline / humic acid loading ratio of 3:2 has the highest overall iron ion removal efficiency, which can reach 80% in the first 30 minutes of the reaction, and can reach the maximum removal efficiency after 60 minutes of reaction, and then maintain balance.

[0083] refer to Figure 9 The figure below compares the total iron ion removal efficiency of the humic acid / tourmaline composite material at different loading times. It can be seen that loading the humic acid / tourmaline material for 18 hours significantly improves the iron ion removal efficiency in the first 30 minutes. After 60 minutes of reaction, the iron ion removal rate in acidic mine drainage reaches over 98.5%.

[0084] refer to Figure 10 The figure below compares the total iron ion removal rate of humic acid / tourmaline composite materials at different loading temperatures. It can be seen that the humic acid / tourmaline material with a loading temperature of 45°C can remove 98.5% of iron ions in the first 30 minutes. After 60 minutes of reaction, the iron ion removal rate in acidic mine drainage water can reach 99%.

[0085] 3. Comparative study on the adsorption performance of iron ions by tourmaline system before and after modification

[0086] Weigh 0.4, 0.6, 0.8, 1.0, and 1.2 g of humic acid / tourmaline composite material, take 5 150 ml conical flasks respectively, add 100 ml of acidic mine wastewater, add the material, and then place the sample on a constant temperature magnetic stirrer at 300 r / min and 45°C for stirring reaction. Sampling is taken at regular intervals, passed through a water filter membrane, and then the total iron content in the sample is determined. At the same time, the same steps are taken for unloaded pure tourmaline for comparison.

[0087] refer to Figure 11 , which is the experimental result of different dosages of humic acid / tourmaline composite materials. According to the information in the figure, as the dosage increases, the composite material has a better effect on removing iron ions in wastewater. When the dosage reaches 10g / L, the maximum removal rate is the same as the maximum removal rate when the dosage is 12g / L, and both reach reaction equilibrium in about 45min of adsorption reaction. Therefore, the optimal dosage of the composite material adsorption reaction is preferably 10g / L.

[0088] refer to Figure 12 The figure below compares the adsorption and removal rates of iron ions from wastewater by unloaded raw tourmaline and loaded composite materials. It can be seen that increasing the dosage to 8 g / L significantly increases the composite material's iron ion removal rate. This is because the unsaturated bonds on the composite material's surface provide active centers for adsorption. The strong electrostatic field surrounding the composite particles attracts charged particles, reducing the concentration of iron ions in the solution.

[0089] The present inventors have found that the total iron ions in actual acid mine wastewater are mainly Fe 3+ , contains very small amounts of Fe 2+ In order to more fully understand the adsorption performance of the humic acid / tourmaline composite material of the present invention, the present inventors investigated the adsorption of Fe 2+ removal effect.

[0090] Experimental process: simulated wastewater was prepared with the drug ferrous sulfate heptahydrate (FeSO4·7H2O) at concentrations of 200mg / L, 400mg / L, 600mg / L, and 1000mg / L, respectively. Concentrated sulfuric acid was used to adjust the pH of the simulated wastewater to about 2.0. 100ml of simulated wastewater of different concentrations was placed in a 150ml conical flask, and 1.0g of humic acid / tourmaline composite material was added. The mixture was placed on a constant temperature magnetic stirrer at 300r / min and stirred at room temperature. Samples were taken at regular intervals, filtered through a water filter membrane, and then the Fe content in the samples was determined by o-phenanthroline spectrophotometry. 2+ content.

[0091] refer to Figure 13 , is a comparison chart of the removal rate of divalent iron ions in simulated wastewater with different concentrations by humic acid / tourmaline composite materials. It can be seen that the composite material has a good effect on Fe2+ It has a good removal effect, and the concentration of Fe in the simulated wastewater is as low as 200 mg / L. 2+ Almost all of them were removed; with the increase of the concentration of simulated wastewater, the removal rate of the composite material decreased, but it was finally maintained at more than 80%, indicating that the material has good adaptability and is also effective in treating high-concentration wastewater.

[0092] The humic acid / tourmaline composite material of the present invention effectively removes total iron ions from acidic mine drainage water and can be used as a filling adsorption medium for permeable reaction walls to stably and efficiently treat iron ions in acidic mine drainage water. In some embodiments, the permeable reaction wall can be manufactured using a commonly used manufacturing process in the art.

[0093] Any matters not mentioned above shall be subject to the existing technology.

[0094] Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art should understand that the above examples are for illustration only and are not intended to limit the scope of the present invention. Those skilled in the art of the present invention may make various modifications or additions to the described specific embodiments or replace them in similar ways, but they will not deviate from the direction of the present invention or exceed the scope defined by the appended claims. Those skilled in the art should understand that any modifications, equivalent replacements, improvements, etc. made to the above embodiments based on the technical essence of the present invention should be included in the scope of protection of the present invention.

Claims

1. Application of a humic acid / tourmaline composite material in the treatment of acid mine wastewater, characterized in that: The pH of the acidic mine wastewater is less than 3, and the total iron ion concentration in the acidic mine wastewater is not higher than 600 mg / L. The preparation method of the humic acid / tourmaline composite material comprises the following specific steps: S1, dissolving humic acid in a 0.5-0.55 mol / L NaOH solution, and then adjusting the pH to 0.9-1.1 with 10-12 mol / L hydrochloric acid to obtain a first solution, heating the first solution in a water bath at 60-65° C., cooling, centrifuging, and drying to obtain pretreated humic acid; S2. Dissolving the pretreated humic acid obtained in step S1 in a NaOH solution, then adding tourmaline in a tourmaline: humic acid mass ratio of 2:3 to 3:2, and then adding a hydrochloric acid solution, adjusting the pH to 5.5 to 6.5, and stirring the reaction at a constant temperature of 35 to 55° C. for 18 to 24 hours. After the reactant is cooled, centrifugation, washing, and drying are performed to obtain a humic acid / tourmaline composite material.

2. The use according to claim 1, characterized in that In step S1, the mass volume ratio of the humic acid to the NaOH solution is 1 g: (25-50) mL.

3. The preparation method according to claim 2, wherein The chemical formula of the tourmaline is NaFe3B3Al6Si6O 27 (OH)3F.

4. The use according to claim 3, characterized in that The particle size of the tourmaline is not less than 325 meshes.

5. The use according to claim 4, wherein The humic acid / tourmaline composite material is added to the acidic mine wastewater, and the addition amount of the humic acid / tourmaline composite material is 4-12 g / L.

6. The use according to claim 1, wherein The humic acid / tourmaline composite material is used for preparing a permeable reaction wall for treating acid mine wastewater.

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