Method for removing manganese ions in acid solution with assistance of solid materials

Abstract

The invention provides a method for removing manganese ions in an acid solution under the assistance of a solid material, and belongs to the technical field of removal of impurities in solutions. The method comprises the following steps: carrying out first mixing and stirring on a filtering medium, alkali, manganese dioxide and manganese salt according to a first preset mass ratio, and carrying out stirring and ore grinding to obtain a first mixed material; carrying out second mixing and stirring on the first mixed material, a binder and a filter medium according to a second preset mass ratio, and granulating to obtain porous solid particles; oxygen in the air directly participates in the effect, the solid particles are prepared into solid materials of high-valence manganese oxide and nanometer manganese oxide materials with activity, and the solid materials are used as filter layers; and introducing an acidic solution containing manganese ions into the filter layer, adding an alkaline solution to control the pH value to be greater than or equal to 2 and less than or equal to 4, and dropwise adding a persulfate solution, so that the persulfate solution and the solid particles synergistically act on the manganese ions, and the manganese ions are removed in the form of trivalent manganese oxide and tetravalent manganese oxide.

Description

Technical Field

[0001] The invention relates to the technical field of impurity removal or resource recovery in a solution, and in particular to a method for removing manganese ions in an acidic solution by using solid materials as an auxiliary. Background Art

[0002] Manganese is one of the most widely existing elements in the natural environment and is widely used in industry. During the resource development process and the recycling process of manganese-containing batteries, manganese will exist in the acidic solution as impurity ions or interfering ions. In order to obtain industrial products with higher purity, it is usually necessary to remove manganese ions from the acidic solution without affecting the recovery of the target product, so as to facilitate the application of industrial products.

[0003] In the related art, an excess amount of a strong oxidant solution is usually added to an acidic solution to remove manganese ions from the solution. However, this removal method requires a long reaction time (about 2 hours), requires the use of an excess of a strong oxidant (the amount of the strong oxidant added needs to be 150% or more of the theoretical amount required to convert divalent manganese ions into manganese dioxide), and the resulting manganese precipitate particles are difficult to filter. Summary of the invention

[0004] In view of this, in order to at least partially solve at least one of the above-mentioned technical problems, the present invention provides a method for removing manganese ions in an acidic solution by using solid materials as an auxiliary.

[0005] According to an embodiment of one aspect of the present invention, a method for removing manganese ions from an acidic solution by using solid materials is provided, comprising: performing a first mixing and stirring of a filter medium, an alkali, manganese dioxide, and a manganese salt according to a first preset mass ratio, and obtaining a first mixed material after stirring and grinding; performing a second mixing and stirring of the first mixed material, a binder, and a filter medium according to a second preset mass ratio, and obtaining porous solid particles after granulation; utilizing oxygen in the air to directly participate in the action, preparing the solid particles to generate a solid material having active high-valent manganese oxide and nano manganese oxide materials, and the solid material is used to serve as a filter layer; passing an acidic solution containing manganese ions into the filter layer, adding an alkaline solution to control 2≤pH≤4 and dropwise adding a persulfate solution, so that the persulfate solution and the solid particles act synergistically on the manganese ions, so that the manganese ions are removed in the form of trivalent manganese oxide and tetravalent manganese oxide.

[0006] According to an embodiment of the present invention, the first mixed material, the binder, and the filter medium are mixed and stirred for a second time according to a second preset mass ratio, and porous solid particles are obtained after granulation, including: mixing part of the first mixed material and the binder to obtain a second mixed material; mixing another part of the first mixed material and the filter medium to obtain a third mixed material; mixing the second mixed material with the third mixed material, and obtaining porous solid particles after granulation.

[0007] According to an embodiment of the present invention, the filter layer is prepared by the following process: the solid materials are mixed evenly and filled into a cylindrical pipe with a diaphragm wrapped at the bottom; the inner diameter of the cylindrical pipe is 30~34mm, and the height of the filter layer is 40~60mm.

[0008] According to an embodiment of the present invention, the solid material of preparing active high-valent manganese oxide and nano manganese oxide materials from solid particles includes: drying and activating the solid particles in sequence; the drying temperature is 110-130°C.

[0009] According to an embodiment of the present invention, the activation treatment conditions are: the solid particles are activated with water vapor at 100° C. for 15 to 25 minutes, and then left to stand for 5 to 15 minutes after activation.

[0010] According to an embodiment of the present invention, the first preset mass ratio is (3-4):1:(1-2):1;

[0011] The stirring grinding treatment time is 1~2h, the temperature is 24~52℃, and the rotation speed is 2000~4000rpm.

[0012] According to an embodiment of the present invention, the second preset mass ratio is 2:1:1.

[0013] According to an embodiment of the present invention, the flow rate of the acidic solution containing manganese ions passing into the filter layer is 8-15 mL / min, and the concentration of persulfate is 0.1-0.8 mol / L.

[0014] According to an embodiment of the present invention, the filter medium includes silicon dioxide; the alkali includes sodium silicate; the binder includes silica gel; and the manganese salt includes at least one of manganese sulfate or a hydrate of manganese sulfate.

[0015] According to an embodiment of the present invention, the concentration of manganese ions in the acidic solution is 0.5-3 g / L.

[0016] According to an embodiment of the present invention, solid particles with a porous structure are formed by mixing and stirring the raw materials and grinding them. The porous structure is conducive to assisting the adsorption of manganese ions when the acidic solution is subsequently passed into the filter layer. The solid particles are activated by oxygen in the air, and the obtained solid material includes active high-valent manganese oxide, such as manganese dioxide or manganese trioxide. On the one hand, the high-valent manganese oxide provides growth nuclei for the oxidation of low-valent manganese ions to form manganese dioxide particles, so as to facilitate the subsequent growth of manganese dioxide particles, thereby avoiding the difficulty of filtering the generated fine particles of manganese dioxide. On the other hand, since the high-valent manganese ions are distributed on the inner surface of the pores of the porous structure, they provide highly active oxidation sites. The persulfate added dropwise enters the pores. Persulfate has strong oxidizing properties and will decompose under acidic conditions to produce free radicals with strong oxidizing properties. Strong oxidants such as persulfate and free radicals work together with active high-valent manganese oxide and nano manganese oxide particles to create a highly oxidizing environment in the pores, making it very easy for the divalent manganese ions entering the pores to lose electrons and undergo oxidation reactions, thereby increasing the manganese valence state and forming trivalent manganese oxides and tetravalent manganese oxides, which are then separated from the acidic solution in the form of precipitation or adsorption on the inner surface of the pores of the solid material.

[0017] When the pH is adjusted to an acidic range between 2 and 4, it is helpful to independently remove the manganese ions in the form of precipitation, while other target metal ions that need to be retained in the acidic solution, such as cobalt, nickel, etc., will not be removed, and the recovery of other target metal ions will not be affected.

[0018] According to an embodiment of the present invention, by utilizing the physical adsorption of the porous structure in the solid particles and the synergistic effect between the solid material and the persulfate, the total amount of persulfate added is 80-97% of the theoretical total amount of oxidation required for the divalent manganese ions in the acidic solution to be completely converted into manganese dioxide, which is lower than the 150% strong oxidant requirement mentioned in the related art, thereby saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0020] Figure 1 A flow chart showing a method for removing manganese ions from an acidic solution using solid materials as an aid according to an embodiment of the present invention;

[0021] Figure 2 A process diagram of a method for removing manganese ions from an acidic solution using solid materials as an aid according to an embodiment of the present invention is shown;

[0022] Figure 3 The electron microscope image and the total number spectrum of the distribution diagram of the surface scanning of the solid material of Example 1 of the present invention after use are shown;

[0023] Figure 4 shows the X-ray diffraction spectrum of quartz sand (silicon oxide) of Example 1 of the present invention;

[0024] Figure 5 A bar chart showing the manganese ion removal effect of the acidic solution of Example 1 of the present invention when no filter layer is used, when a filter layer is used, and when the filter layer is repeatedly used;

[0025] Figure 6 A bar graph showing the manganese ion removal effect of the acidic solution of Example 2 of the present invention when no filter layer is used, when a filter layer is used, and when the filter layer is repeatedly used; and

[0026] Figure 7 A bar chart showing the manganese ion removal effect of the acidic solution of Example 3 of the present invention when no filter layer is used, when a filter layer is used, and when the filter layer is repeatedly used is shown. DETAILED DESCRIPTION

[0027] Below, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of concepts of the present invention.

[0028] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The term "comprising" used herein indicates the existence of features, steps, operations, but does not exclude the existence or addition of one or more other features.

[0029] In the case of using expressions such as "at least one of A, B, and C, etc.", it should generally be interpreted in accordance with the meaning of the expression generally understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.). In the case of using expressions such as "at least one of A, B, or C, etc.", it should generally be interpreted in accordance with the meaning of the expression generally understood by those skilled in the art (for example, "a system having at least one of A, B, or C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0030] In the recycling process of manganese-containing batteries, manganese ions are usually present in the acidic solution as impurities or interferences. One approach in the related art is to oxidize the divalent manganese ions in the aqueous solution into insoluble tetravalent manganese by adding a strong oxidizing agent, and then separate the tetravalent manganese precipitate by physical adsorption. The oxidants used are such as permanganate, ferrate, etc. This method needs to be carried out under higher pH conditions, and the higher the pH of the solution, the better the manganese removal effect. However, in the recycling process of manganese-containing batteries, this method will easily remove the target products that need to be recovered, such as cobalt, nickel and other target products, and the subsequent separation between the target product and the tetravalent manganese precipitate is difficult to achieve.

[0031] In the process of realizing the concept of the present invention, it is found that the solid particles obtained by mixing, stirring, grinding, granulating and other operations of various raw materials have a porous structure. Then, through the activation of oxygen, the solid particles are converted into solid materials with active high-valent manganese oxide and nano manganese oxide particles. Then, the synergistic oxidation between persulfate and the solid material is used to remove manganese ions in the acidic solution.

[0032] Specifically, according to an embodiment of one aspect of the present invention, a method for removing manganese ions from an acidic solution using solid materials is provided. Figure 1 A flow chart of a method for removing manganese ions from an acidic solution using solid materials as an aid according to an embodiment of the present invention is shown. Figure 2 The process diagram of the method for removing manganese ions from an acidic solution using solid materials as an aid in the present invention is shown. Figure 1 and Figure 2 As shown, operations S101 to S104 are included.

[0033] In operation S101, a filter medium, an alkali, manganese dioxide, and a manganese salt are first mixed and stirred according to a first preset mass ratio, and a first mixed material is obtained after stirring and grinding.

[0034] According to the embodiment of the present invention, the manganese salt has a certain acidity, and the addition of alkali helps to adjust the pH value of the first mixed material, which helps the subsequent reaction. The stirring grinding promotes the above raw materials to be fully contacted and evenly distributed.

[0035] In operation S102, the first mixed material, the binder, and the filter medium are mixed and stirred for a second time according to a second preset mass ratio, and porous solid particles are obtained after granulation.

[0036] According to the embodiment of the present invention, the binder can make the above raw materials bond together better to form granules, and after granulation, porous solid particles with more pores are obtained. The formed porous structure is conducive to the adsorption of manganese ions and the diffusion of oxygen in the subsequent reaction process.

[0037] In operation S103, oxygen in the air is directly used to prepare solid particles to generate solid materials having active high-valent manganese oxide and nano manganese oxide particles, and the solid materials are used as a filter layer.

[0038] According to an embodiment of the present invention, based on the variable valence state of manganese, the valence state of some manganese ions in the manganese salt is further increased under the action of oxygen, and converted into manganese dioxide, manganese trioxide and even high-valent manganese oxide with higher oxidative activity, which has a strong electron-accepting ability and is prepared for the subsequent removal of manganese ions in the acidic solution. High-valent manganese oxide and nano manganese oxide particles provide crystal nuclei for the subsequent growth of manganese dioxide particles, avoiding the difficulty of filtering the generated fine particles of manganese dioxide.

[0039] In operation S104, the acidic solution containing manganese ions is passed into the filtration layer, an alkaline solution is added to control the pH to be 2≤pH≤4, and a persulfate solution is added dropwise, so that the persulfate solution and the solid material act synergistically on the manganese ions, so that the manganese ions are removed in the form of trivalent manganese oxides and tetravalent manganese oxides.

[0040] According to the embodiments of the present invention, since high-valent manganese ions are mostly distributed on the inner surface of the pores of the porous structure, providing highly active oxidation sites, the persulfate added dropwise enters the pores. The persulfate has a strong oxidizing property and will decompose under acidic conditions to produce free radicals with strong oxidizing properties. Strong oxidants such as persulfate and free radicals cooperate with active high-valent manganese oxide and nano manganese oxide particles to create a highly oxidizing environment in the pores, so that the divalent manganese ions entering the pores can easily lose electrons and undergo oxidation reactions, thereby increasing the manganese valence state, forming trivalent manganese oxide and tetravalent manganese oxide, which are then separated from the acidic solution in the form of precipitation or adsorption on the inner surface of the pores of the solid material.

[0041] According to an embodiment of the present invention, the solid material is fully contacted with air during the preparation process, so that some manganese compounds are in the state of active high-valent manganese oxide, such as manganese dioxide, manganese trioxide, etc. By utilizing the synergistic interaction of the oxidation potential of nano manganese oxide particles, persulfate, high-valent manganese oxide and the high-concentration oxidized free radicals in the pores, and utilizing the variable valence state of manganese ions and the characteristics of the highly oxidizing environment in the pores, under the condition of controlling pH (2-4), the manganese ions in the acidic solution are removed in the form of trivalent manganese oxide and tetravalent manganese oxide.

[0042] It should be noted that, due to the small particle size and large specific surface area of ​​nano manganese oxide particles, they have strong adsorption performance and surface activity. Nano manganese oxide particles can adsorb manganese ions in acidic solutions, enriching manganese ions on the surface of nano manganese oxide particles, shortening the distance between manganese ions and oxidants in the pores and active high-valent manganese oxide, and increasing the contact opportunities and reaction probability between them.

[0043] According to an embodiment of the present invention, the filter medium includes silicon dioxide, for example, quartz sand can be used as the basic material of the filter layer. There are certain pores between the quartz sand particles, which can play a preliminary filtering role on the solid particle impurities in the acidic solution, and can also provide a supporting structure for the filter layer. The alkali includes sodium silicate, and the alkalinity of sodium silicate helps to play an auxiliary role in regulating the pH of the filter layer. At the same time, sodium silicate also has a certain bonding effect, which can assist the subsequent binder to bond the solid particles together. Sodium silicate may also interact with quartz sand. The binder includes silica gel, which provides bonding properties and helps to bond the above raw materials together to form a solid material. The manganese salt includes at least one of manganese sulfate or a hydrate of manganese sulfate. The manganese salt is the main source of manganese ions in the solid material and is also an important component for forming active high-valent manganese oxide and nano manganese oxide particles. In the process of conducting experiments, it was found that when manganese sulfate or a hydrate of manganese sulfate is used, it can better cooperate with persulfate and remove manganese ions in the acidic solution more thoroughly.

[0044] Specifically, the hydrate of manganese sulfate may be, for example, manganese sulfate monohydrate.

[0045] It should be noted that in the process of using the filter layer to remove manganese ions in the acidic solution, it is necessary to maintain the state of 2≤pH≤4 by adding an alkaline solution, for example, it can be 2, 2.2, 2.5, 3, 3.5 or 4, and the alkaline solution can be at least one of a sodium hydroxide solution, a potassium hydroxide solution, a sodium carbonate solution, and a sodium bicarbonate solution. Since the removal of manganese ions in the acidic solution will release acid radical ions into the acidic solution, causing the pH to drop, if the pH is lower than 2, it will affect the process of the filter layer assisting in the removal of manganese ions in the acidic solution, reducing the removal effect; if the pH is higher than 4, it will affect the target metal ions, such as cobalt or nickel, so that the target metal ions are removed together.

[0046] According to an embodiment of the present invention, the concentration of manganese ions in the acidic solution is 0.5-3 g / L, for example, 0.5 g / L, 1 g / L, 1.5 g / L, 2 g / L, 2.5 g / L or 3 g / L. When the concentration of manganese ions in the acidic solution is within the above range, the synergistic effect of the persulfate solution and the solid material is better, and the removal effect of manganese ions is correspondingly better.

[0047] It should be noted that the filter material has a certain usage limit according to the concentration of the acidic manganese ions to be treated and the conditions for the filtrate to pass through, that is, every 120g of filter layer can treat 5L-20L of acidic solution containing manganese ions.

[0048] According to an embodiment of the present invention, the first preset mass ratio is (3-4):1:(1-2):1, for example, 3:1:1:1, 3:1:2:1, 4:1:1:1 or 4:1:2:1. The stirring grinding treatment time is 1-2 hours, for example, 1 hour, 1.5 hours or 2 hours, the temperature is 24-52°C, for example, 24°C, 25°C, 35°C, 45°C, 50°C or 52°C, and the rotation speed is 2000-4000rpm, for example, 2000rpm, 3000rpm or 4000rpm. The parameters of the stirring grinding are set in the above range, which helps to fully mix the various raw materials so that the obtained solid particles have relatively uniform pores.

[0049] According to an embodiment of the present invention, operation S102 includes sub-operations S1021 - S1023 .

[0050] In sub-operation S1021, parts of the first mixed material and the binder are mixed to obtain a second mixed material.

[0051] In sub-operation S1022, another portion of the first mixed material and the filter medium are mixed to obtain a third mixed material.

[0052] In sub-operation S1023, the second mixed material is mixed with the third mixed material, and porous solid particles are obtained after granulation.

[0053] According to an embodiment of the present invention, a portion of the first mixed material is first mixed with a binder so that the binder can better wrap and bond the filter medium, alkali, manganese dioxide, manganese salt, etc., promote uniform dispersion of the above raw materials, and avoid uneven local bonding. Then, the filter medium is mixed with another portion of the first mixed material so that the filter medium is more evenly mixed in the solid particles, thereby providing a relatively stable physical structure support for the solid particles formed subsequently. By mixing in steps, the physical structure strength of the solid particles is ensured while ensuring the uniformity of dispersion of multiple raw materials.

[0054] In one embodiment, the first mixed material can be mixed with a binder in a mass ratio of 1:1 to obtain a second mixed material; another portion of the first mixed material can be mixed with a filter medium in a mass ratio of 1:1 to obtain a third mixed material; and then the second mixed material and the third mixed material are mixed and stirred to obtain porous solid particles.

[0055] Preferably, after granulation, a drying treatment may be performed as required to make the obtained solid particles stronger and have better integrity.

[0056] According to an embodiment of the present invention, the filter layer is prepared by the following process: the solid materials are mixed evenly, and laid and filled into a cylindrical pipe with a diaphragm wrapped at the bottom; the inner diameter of the cylindrical pipe is 30-34 mm, for example, 30 mm, 32 mm or 34 mm, preferably 32 mm. The material of the cylindrical channel includes plastic, and the diaphragm can be, for example, a filter cloth. The height of the filter layer is 40-60 mm, for example, 40 mm, 50 mm or 60 mm. The mesh number of the filter medium is 160-200 mesh, for example, 160 mesh, 180 mesh or 200 mesh. Setting the mesh number of the filter medium in the above range and adjusting the cylindrical channel in the above range helps to fully contact with the acidic solution while allowing the acidic solution to pass through the filter layer smoothly. Further, setting the height of the filter layer in the above range further helps to improve the removal effect of manganese ions.

[0057] According to an embodiment of the present invention, operation S103 specifically includes drying and activating the solid particles in sequence; the drying temperature is 110-130°C, for example, 110°C, 120°C or 130°C, preferably 120°C.

[0058] Preferably, the activation treatment conditions are: at 100°C, the solid particles are activated with water vapor for 15 to 25 minutes, for example, 15 minutes, 20 minutes or 25 minutes, preferably 20 minutes, and the activation is allowed to stand for 5 to 15 minutes, for example, 5 minutes, 10 minutes or 15 minutes, preferably 10 minutes. During the activation process, water vapor can enter the pores of the solid particles, which helps to convert the manganese ions in the solid particles into active high-valent manganese oxide and nano manganese oxide particles together with oxygen, and at the same time, helps to adjust the size and shape of the pores to make them more regular and stable. By standing, the solid particles stabilize the structural changes that occur during the activation treatment.

[0059] According to an embodiment of the present invention, the second preset mass ratio is 2:1:1. By setting the second preset mass ratio and adjusting the first mixed material to be in a more state, it is possible to ensure that there are sufficient active substances in the solid particles to participate in the oxidation of manganese ions in the solid particles. The addition of the filter medium helps to build an interconnected and moderate pore network, ensuring that the manganese ions to be removed in the subsequent acidic solution can fully contact the active substances (high-valent manganese oxide and nano manganese oxide particles, etc.) inside the filter layer.

[0060] According to an embodiment of the present invention, the flow rate at which the acidic solution containing manganese ions is passed into the filter layer is 8 to 15 mL / min, for example, 8 mL / min, 10 mL / min, 12 mL / min, 14 mL / min or 15 mL / min. The concentration of persulfate is 0.1 to 0.8 mol / L, for example, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L or 0.8 mol / L. By setting the flow rate to the above range, it is helpful to have a good filtering effect while ensuring sufficient reaction. By setting the concentration of persulfate to the above range, it is helpful to provide sufficient oxidation capacity.

[0061] In one specific embodiment, the preparation process of the solid material is as follows:

[0062] Under stirring grinding conditions of 30° C. and 3000 rpm, quartz sand solid of 160-200 mesh, sodium silicate, manganese dioxide and manganese sulfate monohydrate reagent were mixed and ground at a mass ratio of 3:1:1:1 for 1.2 hours to obtain a pretreated mixed material.

[0063] A part of the mixed material is mixed with silica gel at a mass ratio of 1:1, and another part of the mixed material is mixed with quartz sand at a mass ratio of 1:1, and then mixed twice and stirred to obtain porous solid particles.

[0064] The porous solid particles are dried at 120°C, placed in a conical flask, activated with 100°C steam for 20 minutes at 100°C, and allowed to stand for 10 minutes to obtain a solid material that can be used as an auxiliary to remove manganese ions in an acidic solution.

[0065] The specific process of using solid materials to assist in removing manganese ions from acidic solutions is as follows:

[0066] The solid material is filled into a 32mm (inner diameter) plastic tube, a filter cloth is set at the bottom of the tube, and it is vibrated appropriately. Then, the acidic liquid containing manganese ions is passed through the filter layer at a speed of 10mL / min, and 0.5mol / L persulfate is added dropwise to the filter material (the total amount of persulfate added is 85% of the theoretical total amount of oxidation required for the divalent manganese ions in the acidic solution to be completely converted into manganese dioxide). When the acidic solution passes through the filter layer, alkaline solution is appropriately added to control the pH to 2.5-3.0, so as to achieve the removal of manganese ions in the acidic solution.

[0067] The solid material that has reached its usage limit (the manganese ion concentration after filtration is higher than 0.3g / L) is used to replace the quartz sand and manganese dioxide in the raw materials, and the above operation is repeated.

[0068] According to an embodiment of the present invention, the manganese ions in the acidic solution are removed by solid materials, which not only greatly reduces the amount of oxidant used (150% of the theoretical amount is often used in the related art), but also reduces the filtration process after the acidic solution forms a precipitate after the manganese ions are removed. The present invention can realize the oxidation and filtration process of manganese ions at the same time through the filter layer, and can more efficiently realize the effective removal of manganese ions in the acidic solution.

[0069] According to an embodiment of the present invention, there are active high-valent manganese oxide and nano manganese oxide particles in the solid material, and they are fully in contact with air during the solid-phase stirring mill reaction process, so that some manganese compounds present the state of active high-valent manganese oxide, and at the same time, the persulfate is combined with the high-valent manganese compound to realize the composite action of the oxidant and the active manganese compound, so that the divalent manganese ions in the solution can be removed in the form of trivalent manganese oxide and tetravalent manganese oxide. It should be particularly noted that although persulfate is a strong oxidant, it can oxidize manganese ions in acidic solution to form tetravalent manganese oxide. However, when the solid material is used, the persulfate added to the material is less than the theoretical reaction amount when generating manganese dioxide precipitation. The specific reason may be that the persulfate and the active manganese oxide have a certain relationship in the chemical reaction mode in the pores. For example, there may be a porous structure, active high-valent manganese oxide, and nano manganese oxide particles in the preparation process of the filter layer, so that the manganese ions in the acidic solution are quickly converted to high-valent manganese oxides, and some manganese oxides may exist as trivalent manganese oxides. The invention uses the prepared solid material as a filter layer, so that the acid solution containing manganese ions and persulfate pass through the filter layer under certain conditions to obtain the acid solution with manganese ions removed.

[0070] In the related art, the removal of manganese ions in the solution usually requires a long reaction time (about 2 hours). The present invention constructs a filter layer so that the obtained acidic solution can be taken at any time, which is more convenient and quick.

[0071] The present invention is further described below by embodiments and related test experiments and results thereof. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention. However, it is obvious that one or more embodiments may also be implemented without these specific details. And, in the absence of conflict, the details in the following embodiments may be combined into other feasible embodiments at will.

[0072] It should be noted that the following specific examples are only for illustration, and the protection scope of the present invention is not limited thereto. The chemicals and raw materials used in the following examples are all commercially available or homemade by recognized processing methods.

[0073] Embodiment 1:

[0074] Under stirring grinding conditions of 30° C. and 3000 rpm, a mixture of 30 g of 160-200 mesh quartz sand solid, 10 g of sodium silicate, 10 g of manganese dioxide and 10 g of manganese sulfate monohydrate was ground for 1.2 hours to obtain a pretreated mixture.

[0075] 30 g of a part of the pretreated mixed material was stirred and mixed with 30 g of silica gel, and another part of the mixed material was stirred and mixed with 30 g of solid quartz sand. Finally, the above materials were mixed and stirred to obtain solid particles.

[0076] The solid particles are dried at 120° C., placed in a conical flask, and activated with 100° C. steam for 20 minutes at 100° C., and allowed to stand for 10 minutes to obtain a solid material that can be used as an auxiliary material for removing manganese ions from an acidic solution.

[0077] The obtained solid material is filled into a 32 mm (inner diameter) plastic tube, a filter cloth is set at the bottom of the tube, and it is vibrated appropriately. Then, 300 mL of an acidic liquid containing manganese ions (1.94 g / L) is passed through the filter material at a speed of 10 mL / min, and 0.5 mol / L of sodium persulfate is added dropwise to the filter material (the total amount of sodium persulfate added is 85% of the theoretical total amount of oxidation required for the divalent manganese ions in the solution to be completely converted into manganese dioxide). The sodium persulfate liquid is slowly added at a speed of 3 mL every 5 minutes for 30 minutes. At the same time, when the acidic solution passes through the filter material, sodium hydroxide solution is appropriately added to control the pH to 2.5-3.0, so that the manganese ions in the solution can be removed. The concentration of manganese ions after removal is 0.137 g / L, and the removal rate of manganese ions is 92.9%.

[0078] Figure 3 The electron microscope image and the total number spectrum of the distribution diagram of the surface scanning of the solid material of Example 1 of the present invention after use are shown. Figure 3 As shown, it can be seen that the formed solid material has a porous morphology. At the same time, it can be seen from the distribution diagram that manganese is adsorbed on it, and oxygen also exists, indicating that it has a good removal effect on manganese ions in acidic solution. Figure 4 FIG. 1 shows an X-ray diffraction spectrum of quartz sand (silicon oxide) of Example 1 of the present invention. Figure 4 As shown, it can be seen that there is a relatively pure silicon oxide structure, combined with Figure 3 It can be seen from the total number spectrum of the distribution diagram that it can be considered that there are amorphous or highly active high-valent manganese oxide compounds in the solid material after use.

[0079] Figure 5 The bar graph shows the manganese ion removal effect of the acidic solution of Example 1 of the present invention when no filter layer is used, when a filter layer is used, and when the filter layer is reused 10 times. Figure 5 As shown, if the filter layer is not used and sodium persulfate is directly added, the removal effect of manganese ions is poor at the same pH range, about 70%. After using the filter layer, the removal effect of manganese ions is better, at 92.9%. After the filter layer is reused 10 times, the removal effect is about 84%. Since the manganese salt is consumed, the high-valent manganese oxide and nano manganese oxide particles formed are relatively reduced, thereby reducing the removal effect of manganese ions in the acidic solution. The filter layer has reached its usage limit after being used 10 times.

[0080] The filter material that has reached its use limit (after treating 8L of acidic liquid solution containing 1.94g / L of manganese ions, the manganese ions in the filtrate exceed 0.3g / L) is used to replace the quartz sand and manganese dioxide in the mixed material. By repeating the above operation, a solution with a manganese ion concentration of 0.152g / L can be obtained, and the manganese ion removal effect is 92.2%, indicating that quartz sand and manganese dioxide can be recycled and reused to save costs.

[0081] Embodiment 2:

[0082] Under stirring grinding conditions of 50° C. and 2500 rpm, a mixture of 40 g of 160-200 mesh quartz sand solid, 10 g of sodium silicate, 20 g of manganese dioxide and 10 g of manganese sulfate monohydrate (mass ratio 4:1:2:1) was ground for 1.5 hours to obtain a pretreated mixture.

[0083] 40 g of a part of the pretreated mixed material was stirred and mixed with 40 g of silica gel, and another part of the mixed material was stirred and mixed with 40 g of solid quartz sand. Finally, the above materials were mixed and stirred to obtain solid particles.

[0084] The solid particles are dried at 120° C., placed in a conical flask, and activated with 100° C. steam for 20 minutes at 100° C., and allowed to stand for 10 minutes to obtain a solid material that can be used as an auxiliary material for removing manganese ions from an acidic solution.

[0085] The obtained solid material is filled into a 32 mm (inner diameter) plastic tube, a filter cloth is set at the bottom of the tube, and it is vibrated appropriately. Then, 320 mL of an acidic liquid containing manganese ions (2.96 g / L) is passed through the filter material at a speed of 8 mL / min, and 0.6 mol / L of sodium persulfate is added dropwise to the filter material (the total amount of sodium persulfate added is 91% of the theoretical total amount of oxidation required for the divalent manganese ions in the solution to be completely converted into manganese dioxide). The sodium persulfate liquid is slowly added at a speed of 6.5 mL per 10 minutes for 40 minutes. During the process of the acidic solution passing through the filter material, sodium hydroxide solution is appropriately added to control the pH to 3.0-3.5, so as to realize the removal of manganese ions in the solution. After removal, the concentration of manganese ions is 0.167 g / L, and the removal rate of manganese ions is 94.4%.

[0086] Figure 6 The bar graph shows the manganese ion removal effect of the acidic solution of Example 2 of the present invention when the filter layer is not used, the filter layer is used, and the filter layer is reused three times. Figure 6 As shown in the figure, if the filter layer is not used and sodium persulfate is directly added, the removal effect of manganese ions is poor at the same pH range, which is about 85%. After the filter layer is used, the removal effect of manganese ions is better, at 94.4%. After the filter layer is reused three times, the manganese salt in it is consumed, resulting in a relative decrease in the formation of high-valent manganese oxide and nano manganese oxide particles, thereby reducing the removal effect of manganese ions in the acidic solution to about 93%.

[0087] The filter material that has reached its usage limit (after treating 5L of acidic liquid solution containing 2.96g / L of manganese ions, the manganese ions in the filtrate exceed 0.3g / L) is used to replace the quartz sand and manganese dioxide in the mixed material. By repeating the above operation, a solution with a manganese ion concentration of 0.184g / L can be obtained, and the manganese ion removal efficiency is 93.8%.

[0088] Embodiment 3:

[0089] Under stirring grinding conditions of 30° C. and 3500 rpm, a mixture of 30 g of 160-200 mesh quartz sand solid, 10 g of sodium silicate, 10 g of manganese dioxide and 10 g of manganese sulfate monohydrate (mass ratio of 3:1:1:1) was ground for 1.5 hours to obtain a pretreated mixture.

[0090] 30 g of a part of the pretreated mixed material was stirred and mixed with 30 g of silica gel, and another part of the mixed material was stirred and mixed with 30 g of solid quartz sand. Finally, the above materials were mixed and stirred to obtain solid particles.

[0091] The solid particles are dried at 120° C., placed in a conical flask, and activated with 100° C. steam for 20 minutes at 100° C., and allowed to stand for 10 minutes to obtain a solid material that can be used as an auxiliary material for removing manganese ions from an acidic solution.

[0092] The obtained solid material is filled into a 32 mm (inner diameter) plastic tube, a filter cloth is set at the bottom of the tube, and it is vibrated appropriately. Then, 400 mL of an acidic liquid containing manganese ions of 0.5 g / L is passed through the filter material at a speed of 8 mL / min, and 0.1 mol / L of sodium persulfate is added dropwise to the filter material (the total amount of sodium persulfate added is 97% of the theoretical total amount of oxidation required for the divalent manganese ions in the solution to be completely converted into manganese dioxide). The persulfate liquid is slowly added at a speed of 7 mL per 10 minutes for 50 minutes. At the same time, during the process of the acidic solution passing through the filter material, sodium hydroxide solution is appropriately added to control the pH to 3.0-3.5, so that the manganese ions in the solution can be removed. After removal, the concentration of manganese ions is 0.097 g / L, and the removal rate of manganese ions is 80.6%. The reason for the relatively low removal rate is that the concentration of manganese ions in the acidic liquid itself is low, which makes it twice as difficult to remove.

[0093] Figure 7 The bar graph shows the manganese ion removal effect of the acidic solution of Example 3 of the present invention when the filter layer is not used, the filter layer is used, and the filter layer is reused 10 times. Figure 7 As shown in the figure, if the filter layer is not used and sodium persulfate is directly added, the removal effect of manganese ions is poor at the same pH range, about 20%. After the filter layer is used, the removal effect of manganese ions is better, at 80.6%. After the filter layer is reused 10 times, the removal effect of manganese ions is 40%. Since the manganese salt is consumed, the high-valent manganese oxide and nano manganese oxide particles formed are relatively reduced, and due to the large number of repeated uses, the removal effect of manganese ions in the acidic solution is reduced, reaching the limit of use.

[0094] The filter material that has reached its usage limit (after treating 20L of acidic liquid solution containing 0.5g / L of manganese ions, the manganese ions in the filtrate exceed 0.3g / L) is used to replace the quartz sand and manganese dioxide in the mixed material. By repeating the above operation, a solution with a manganese ion concentration of 0.102g / L can be obtained, and the manganese ion removal efficiency is 79.6%.

[0095] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for removing manganese ions from an acidic solution using solid materials, comprising: The filter medium, the alkali, the manganese dioxide and the manganese salt are first mixed and stirred according to a first preset mass ratio, and a first mixed material is obtained after stirring and grinding; The first mixed material, the binder, and the filter medium are mixed and stirred for a second time according to a second preset mass ratio, and porous solid particles are obtained after granulation; The solid particles are prepared by directly using oxygen in the air to generate solid materials having active high-valent manganese oxide and nano manganese oxide particles, and the solid materials are used as a filter layer; The acidic solution containing manganese ions is passed into the filter layer, an alkaline solution is added to control the pH value to be 2≤pH≤4, and a persulfate solution is added dropwise, so that the persulfate solution and the solid material act synergistically on the manganese ions, so that the manganese ions are removed in the form of trivalent manganese oxides and tetravalent manganese oxides.

2. The method according to claim 1, wherein: The step of mixing the first mixed material, the binder, and the filter medium according to a second preset mass ratio for a second time and granulating the mixed material to obtain porous solid particles comprises: Mixing part of the first mixed material and a binder to obtain a second mixed material; Mixing another portion of the first mixed material and the filter medium to obtain a third mixed material; The second mixed material is mixed with the third mixed material, and porous solid particles are obtained after granulation.

3. The method according to claim 1, wherein: The filter layer is prepared by the following process: The solid materials are mixed evenly and filled into a cylindrical pipe with a diaphragm wrapped at the bottom; the inner diameter of the cylindrical pipe is 30-34 mm, and the height of the filter layer is 40-60 mm.

4. The method according to claim 1, wherein: The process of preparing the solid particles to generate active high-valent manganese oxide and nano manganese oxide materials comprises: The solid particles are sequentially dried and activated; The temperature of the drying process is 110-130°C.

5. The method according to claim 4, wherein: The conditions of the activation treatment are: The solid particles are activated with water vapor at 100° C. The activation time is 15 to 25 minutes, and the solid particles are left to stand for 5 to 15 minutes after activation.

6. The method according to claim 1, wherein: The first preset mass ratio is (3-4):1:(1-2):1; The stirring grinding treatment time is 1-2 hours, the temperature is 24-52° C., and the rotation speed is 2000-4000 rpm.

7. The method according to claim 1, wherein: The second preset mass ratio is 2:1:

1.

8. The method according to claim 1, wherein: The flow rate of the acidic solution containing manganese ions passing into the filter layer is 8-15 mL / min; The concentration of the persulfate is 0.1-0.8 mol / L.

9. The method according to claim 1, wherein: The filter medium includes silica; The base includes sodium silicate; The adhesive comprises silica gel; The manganese salt includes at least one of manganese sulfate or a hydrate of manganese sulfate.

10. The method according to claim 1, wherein: The concentration of manganese ions in the acidic solution is 0.5-3 g / L.

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