A flaky spherical manganese tetraoxide, its preparation method and application

Abstract

The present invention discloses a flaky spherical manganese tetraoxide, its preparation method and application. The manganese tetraoxide is used as an adsorption material in wastewater purification and solution impurity removal processes. The preparation method includes: (1) preparing or obtaining a mixed salt solution containing manganese element and element A; (2) using a mixture of ammonia water and water as the reaction bottom liquid, adding the mixed salt solution, ammonia water and liquid caustic into the reaction bottom liquid for reaction, continuously introducing air and maintaining stirring to obtain a reaction slurry; (3) performing post-treatment on the reaction slurry to obtain the flaky spherical manganese tetraoxide. The flaky spherical manganese tetraoxide of the present invention can achieve refined adsorption of impurities, is not easy to fall off, has a high adsorption rate, and has high application value as an adsorption material; the preparation method is easy to industrialize, has low cost, and can realize the control of the physical indexes of the final product through parameter adjustment.

Description

Technical Field

[0001] The present invention relates to the technical field of materials, and particularly to a flaky spherical manganese tetraoxide with uniform morphology, good impurity adsorption effect, and fine adsorption, and a preparation method and application thereof. Background Art

[0002] In the fields of wastewater purification and solution impurity removal, especially in the treatment of heavy metal wastewater, manganese tetraoxide is a commonly used adsorption material. The common methods for using manganese tetraoxide to adsorb impurities mainly include: ① adding manganese tetraoxide to the adsorbent to improve the adsorption performance, and ② using the strong adsorption of in-situ generated manganese tetraoxide to remove impurity elements. For example, Patent CN105006263B treats radioactive waste liquid in nuclear power plants by in-situ generating manganese tetraoxide.

[0003] Manganese tetraoxide as a conventional adsorption material is generally porous manganese tetraoxide with a high specific surface area and high particle size. However, the pore spacing of this morphology of manganese tetraoxide is relatively large microscopically, so the degree of fine adsorption of impurity elements is not high, the adsorption rate is low, and the adsorbed impurities are easy to fall off; while the in-situ generation of manganese tetraoxide coprecipitation method is to remove impurities during the generation of manganese tetraoxide, which involves the field of chemical precipitation, the process is relatively complex, and the cost is also relatively high. Summary of the Invention

[0004] The present invention provides a manganese tetraoxide with a flaky spherical morphology, a preparation method and an application thereof, so as to solve the technical problems of poor adsorption effect and low degree of refinement of the existing manganese tetraoxide adsorption material, and poor economy and complex process of the existing impurity removal process.

[0005] To solve the above technical problems, the technical solution proposed by the present invention is as follows:

[0006] A preparation method of a flaky spherical manganese tetraoxide, comprising the following steps:

[0007] (1) Preparing or taking a mixed salt solution containing manganese element and element A, where the element A includes at least one element of aluminum, nickel, cadmium, and cobalt;

[0008] (2) Using a mixture of ammonia water and water as the reaction bottom liquid, introducing the mixed salt solution, complexing agent, and alkaline substance into the reaction bottom liquid for reaction. During the reaction process, continuously introduce air into the reaction bottom liquid and keep stirring. After the reaction is completed, a reaction slurry is obtained;

[0009] (3) Performing post-treatment on the reaction slurry to obtain the void spherical manganese tetraoxide.

[0010] The design concept of the above technical solution is that by adopting the solution co-precipitation method, the product gradually grows from crystal nuclei into a flaky spherical morphology structure with uniform size under high-magnification SEM. Compared with the commonly used manganese tetraoxide adsorbents, the product of this technical solution is easier to achieve refined adsorption, has a better adsorption effect on certain specific impurities. When the impurities come into contact with the product, they can penetrate into the lamellae of the flaky sphere, making it easier to adsorb impurities. Moreover, the flaky spherical shape also provides more adsorption space for the product, and it is not easy to fall off, resulting in a higher adsorption rate. At the same time, during the reaction process, by controlling the specific adjustment of conditions such as stirring, pH, temperature, the amount of complexing agent, and reaction time of the reaction, the control of the physical indexes of the final sample can be achieved. For different impurity removal situations and requirements, manganese tetraoxide materials with different indexes can be produced for targeted adsorption and impurity removal.

[0011] As a further preference of the above technical solution, in step (1), the concentration of manganese element in the mixed salt solution is 60 - 130 g / L, and the concentration of element A is 1 - 5 g / L.

[0012] As a further preference of the above technical solution, in step (1), the mixed salt solution is obtained by dissolving soluble manganese salt and soluble A salt in deionized water. The soluble manganese salt includes at least one of manganese sulfate, manganese nitrate, and manganese chloride. The soluble A salt includes at least one of aluminum nitrate, aluminum sulfate, aluminum acetate, aluminum chloride, nickel nitrate, nickel sulfate, nickel acetate, nickel chloride, cadmium nitrate, cadmium sulfate, cadmium acetate, cadmium chloride, cobalt nitrate, cobalt sulfate, cobalt acetate, and cobalt chloride.

[0013] As a further preference of the above technical solution, in step (2), the complexing agent includes at least one of EDTA, ammonium chloride, ammonium sulfate salt, and ammonia water, and the concentration of the complexing agent is 7% - 15%; the alkaline substance includes at least one of liquid caustic, potassium hydroxide solution, and lime milk, and the mass concentration of the alkaline substance is 20% - 40%. The concentration of ammonium in the reaction bottom liquid is 0.1 - 0.3 mol / L.

[0014] As a further preference of the above technical solution, in step (2), the feeding flow rate of the mixed salt solution is 1 - 3 l / h, the feeding flow rate of the complexing agent is 0.1 - 0.3 L / h, and the feeding flow rate of the alkaline substance is 0.1 - 0.3 L / h.

[0015] As a further preference of the above technical solution, in step (2), the feeding flow rate of the air is 0.6 - 1.2 m 3 / h.

[0016] As a further preference of the above technical solution, in step (2), the pH of the reaction system is controlled at 8.5 - 11.0.

[0017] As a further preference of the above technical solution, in step (2), the reaction temperature of the mixed salt solution, complexing agent and alkaline substance is 40-80 °C, and the reaction time is 10-40 h.

[0018] As a further preference of the above technical solution, in step (3), the post-treatment operation includes filtration, washing and drying treatments carried out in sequence; the filtration treatment is carried out by suction filtration using a Buchner funnel; the washing treatment is to add deionized water to the solid obtained by suction filtration and carry out suction washing, and the drying treatment is carried out by drying in a constant temperature oven, and the drying temperature is 90-120 °C.

[0019] Based on the same inventive concept, the present invention also provides a flaky spherical manganese tetraoxide prepared by the preparation method described in the above technical solution.

[0020] As a further preference of the above technical solution, the particle size D50 of the flaky spherical manganese tetraoxide is 3-20 μm, and the specific surface area is 3-20 m 2 / g.

[0021] Based on the same inventive concept, the present invention also provides an application of the flaky spherical manganese tetraoxide described in the above technical solution, which is used as an adsorption material in wastewater purification and solution impurity removal processes.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 is the process flow chart of the preparation method of Example 1;

[0026] Figure 2 is the particle size distribution diagram of the flaky spherical manganese tetraoxide product of Example 1;

[0027] Figure 3 and Figure 4 is the SEM diagram (at different magnification) of the flaky spherical manganese tetraoxide product of Example 1;

[0028] Figure 5 is the particle size distribution diagram of the flaky spherical manganese tetraoxide product of Example 2;

[0029] Figure 6 and Figure 7SEM images (at different magnifications) of the flaky spherical manganese tetraoxide product of Example 2. Detailed implementation manners

[0030] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways defined and covered by the claims.

[0031] Example 1:

[0032] The flaky spherical manganese tetraoxide product of this example, as Figure 1 shown, is prepared by the following method:

[0033] (1) Weigh manganese sulfate and aluminum sulfate according to a manganese concentration of 80 g / L and an aluminum concentration of 2 g / L respectively, dissolve them in deionized water to form a mixed salt solution, mark it as Agent A, prepare 32% liquid caustic soda and mark it as Agent B, prepare 8% ammonia water and mark it as Agent C, and set aside.

[0034] (2) Add deionized water to a 30 L synthesis kettle to submerge the upper edge of the stirring paddle, add Agent C dropwise to make the pH reach 9.3 - 9.5, then start stirring and heating, set the stirring rate to 500 r / min, heat to 50 °C and keep it at a constant temperature, and then continuously introduce air into the liquid in the synthesis tank, with the air flow rate set at 0.8 m 3 / h.

[0035] (3) Simultaneously pump Agents A, B, and C into the synthesis tank through a peristaltic pump. Among them, the feeding flow rate of Agent A is 1.4 L / h; the feeding flow rate of Agent B is between 0.5 - 0.7 L / h, specifically controlled by the pH in the tank at 9.3 - 9.7; the feeding flow rate of Agent C is 0.15 L / h.

[0036] (4) During the reaction process, control the pH of the slurry in the synthesis tank by controlling the flow rate of Agent B. The pH is controlled between 9.3 - 9.7. During the process, detect the growth of the slurry particle size. When the particle size grows to the required value and the reaction stops, the reaction slurry is obtained.

[0037] (5) Take the reaction slurry for solid-liquid separation (filtration by a Buchner funnel). The obtained solid part is washed and then dried in an oven at 100 °C to obtain a flaky spherical manganese tetraoxide product. This product can be used as an adsorbent material in the processes of removing impurities from wastewater and solutions. Test this product, the specific surface area is 12 m 2 / g, the particle size distribution diagram is as Figure 2 shown, the particle size D50 is 6.5 μm, and the SEM images are as Figure 3 , Figure 4 shown.

[0038] Example 2:

[0039] The flaky spherical manganese tetraoxide product of this embodiment is prepared by the following method:

[0040] (1) Weigh manganese sulfate and aluminum sulfate according to a manganese concentration of 120 g / L and an aluminum concentration of 3 g / L respectively, dissolve them in deionized water to form a mixed salt solution, mark it as Agent A, prepare a 32% potassium hydroxide solution and mark it as Agent B, prepare a 10% ammonia water and mark it as Agent C, and set aside.

[0041] (2) Add deionized water to a 30 L synthesis kettle to submerge the upper edge of the stirring paddle, add Agent C dropwise to make the pH reach 9.5 - 10, then turn on stirring and heating, set the stirring rate to 600 r / min, heat to 70 °C and keep it at a constant temperature, and then continuously introduce air into the liquid in the synthesis tank, with the air flow rate set at 1.2 m 3 / h.

[0042] (3) Simultaneously pump Agents A, B, and C into the synthesis tank through a peristaltic pump. The feeding flow rate of Agent A is 1.0 L / h; the feeding flow rate of Agent B is between 0.3 - 0.6 L / h, specifically controlled by the pH in the tank at 9.5 - 9.7; the feeding flow rate of Agent C is 0.12 L / h.

[0043] (4) During the reaction process, control the pH of the slurry in the synthesis tank by controlling the flow rate of Agent B, with the pH controlled between 9.5 - 9.7. Detect the growth of the slurry particle size during the process. When the particle size grows to the required value and the reaction stops, obtain the reaction slurry.

[0044] (5) Take the reaction slurry for solid-liquid separation (filtration by Buchner funnel). The obtained solid part is washed and then dried in an oven at 120 °C to obtain the flaky spherical manganese tetraoxide product. Test this product, with a specific surface area of 20 m 2 / g, the particle size distribution diagram is as shown in Figure 5 , the particle size D50 is 5 μm, and the SEM diagrams are as shown in Figure 6 , Figure 7 .

[0045] Example 3:

[0046] (1) Weigh manganese sulfate and nickel sulfate according to a manganese concentration of 80 g / L and a nickel concentration of 5 g / L respectively, dissolve them in deionized water to form a mixed salt solution, mark it as Agent A, prepare 32% liquid caustic soda and mark it as Agent B, prepare 8% ammonia water and mark it as Agent C, and set aside.

[0047] (2) Add deionized water to a 30 L synthesis kettle to submerge the upper edge of the stirring paddle, add Agent C dropwise to make the pH reach 9.3 - 9.5, then turn on stirring and heating, set the stirring rate to 500 r / min, heat to 50 °C and keep it at a constant temperature, and then continuously introduce air into the liquid in the synthesis tank, with the air flow rate set at 0.8 m 3 / h.

[0048] (3) Simultaneously pump agents A, B, and C into the synthesis tank through a peristaltic pump, where the feeding flow rate of agent A is 1.4 L / h; the feeding flow rate of agent B is between 0.5 and 0.7 L / h, specifically controlled by the pH value in the tank at 9.3 - 9.7; the feeding flow rate of agent C is 0.15 L / h.

[0049] (4) During the reaction process, control the pH of the slurry in the synthesis tank by controlling the flow rate of agent B. The pH is controlled between 9.3 and 9.7. During the process, detect the growth of the slurry particle size. When the particle size grows to the required value and the reaction stops, the reaction slurry is obtained.

[0050] (5) Take the reaction slurry for solid-liquid separation (filtration by Buchner funnel). The obtained solid part is washed and then dried in an oven at 100 °C to obtain flaky spherical manganese tetraoxide products. These products can be used as adsorption materials in the processes of removing impurities from wastewater and solutions. Test the products, and the specific surface area is 15 m 2 / g, and the particle size shows a normal distribution.

[0051] Comparative Example 1:

[0052] The difference in the preparation of the manganese tetraoxide adsorption material in this comparative example from that in Example 1 is that in step (1) of this comparative example, agent A is only prepared from manganese sulfate without adding aluminum sulfate.

[0053] Comparative Example 2:

[0054] The difference in the preparation of the manganese tetraoxide adsorption material in this comparative example from that in Example 2 is that in step (1) of this comparative example, agent A is only prepared from manganese sulfate without adding aluminum sulfate.

[0055] Comparative Example 3:

[0056] The difference in the preparation of the manganese tetraoxide adsorption material in this comparative example from that in Example 3 is that in step (1) of this comparative example, agent A is only prepared from manganese sulfate without adding aluminum sulfate.

[0057] Do not add nickel sulfate.

[0058] Conduct oil absorption performance tests on the manganese tetraoxide materials of Examples 1 - 3 and Comparative Examples 1 - 3 respectively, and detect the adsorption amount of the manganese tetraoxide materials to oily substances. The results are shown in Table 1.

[0059] Table 1 Adsorption test results of manganese tetraoxide materials in each example and comparative example for oily substances

[0060]

[0061] The manganese tetraoxide materials of Examples 1 to 3 and Comparative Examples 1 to 3 were used to treat sewage respectively, and the reduction rates of COD and SS in water were detected. The results are shown in Table 2.

[0062] Table 2 Adsorption test results of manganese tetraoxide materials in each example and comparative example on sewage

[0063]

[0064] The results show that the flaky spherical manganese tetraoxide materials prepared in Examples 1 to 3 of the present invention have good purification effects on sewage, among which the reduction rate of COD is more than 85%, and the reduction rate of SS is more than 70%, which is better than the manganese tetraoxide materials prepared in Comparative Examples 1 to 3.

[0065] The above are only the preferred embodiments of this application and are not used to limit this application. For those skilled in the art, various changes and modifications can be made to this application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the protection scope of this application. The above is only the preferred implementation mode of the present invention, and the protection scope of the present invention is not limited to the above embodiments. For those skilled in the art of this technology, the improvements and transformations obtained without departing from the technical concept of the present invention should also be regarded as within the protection scope of the present invention.

Claims

1. A preparation method of flaky spherical manganese tetroxide, characterized in that, It includes the following steps: (1) Prepare or obtain a mixed salt solution containing manganese element and element A, where the element A includes at least one element among aluminum, nickel, cadmium, and cobalt; the concentration of manganese element in the mixed salt solution is 60 - 130 g / L, and the concentration of element A is 1 - 5 g / L; (2)Using a mixture of ammonia water and water as the reaction bottom liquid, introducing the mixed salt solution, complexing agent and alkaline substance into the reaction bottom liquid for reaction. During the reaction process, continuously introduce air into the reaction bottom liquid and keep stirring. After the reaction is completed, the reaction slurry is obtained. The complexing agent includes at least one of EDTA, ammonium chloride, ammonium sulfate salt and ammonia water, and the concentration of the complexing agent is 7% - 15%. The alkaline substance includes at least one of liquid caustic soda, potassium hydroxide solution and lime milk, and the mass concentration of the alkaline substance is 20% - 40%. The concentration of ammonium in the reaction bottom liquid is 0.1 - 0.3 mol / L. The feeding flow rate of the mixed salt solution is 1 - 3 l / h, the feeding flow rate of the complexing agent is 0.1 - 0.3 L / h, and the feeding flow rate of the alkaline substance is 0.1 - 0.3 L / h. The feeding flow rate of the air is 0.6 - 1.2 m 3 / h. The reaction temperature of the mixed salt solution, complexing agent and alkaline substance is 40 - 80 °C, and the reaction time is 10 - 40 h. During the reaction process, the pH of the reaction system is controlled at 8.5 - 11.0; (3) Perform post-treatment on the reaction slurry to obtain the flaky spherical manganese tetraoxide.

2. The preparation method of the flaky spherical manganese tetraoxide according to claim 1, characterized in that, In step (1), the mixed salt solution is obtained by dissolving soluble manganese salt and soluble A salt in deionized water. The soluble manganese salt includes at least one of manganese sulfate, manganese nitrate, and manganese chloride, and the soluble A salt includes at least one of aluminum nitrate, aluminum sulfate, aluminum acetate, aluminum chloride, nickel nitrate, nickel sulfate, nickel acetate, nickel chloride, cadmium nitrate, cadmium sulfate, cadmium acetate, cadmium chloride, cobalt nitrate, cobalt sulfate, cobalt acetate, and cobalt chloride.

3. The preparation method of the flaky spherical manganese tetraoxide according to claim 1 or 2, characterized in that, In step (3), the post-treatment operation includes filtration, washing, and drying processes carried out in sequence; the filtration process uses a Buchner funnel for suction filtration; the washing process is to add deionized water to the solid obtained by suction filtration for suction washing, and the drying process uses a constant-temperature oven for drying, and the drying temperature is 90 - 120 °C.

4. A flaky spherical manganese tetraoxide, characterized in that, It is prepared by using the preparation method described in any one of claims 1 - 3.

5. The sheet-shaped spherical manganese tetraoxide according to claim 4, wherein The particle size D50 of the flaky spherical manganese tetroxide is 3 to 20 μm, and the specific surface area is 3 to 20 m 2 / g.

6. Use of the sheet-like spherical manganese tetroxide according to claim 4 or 5, characterized in that, The flaky spherical manganese tetraoxide is used as an adsorbent material in wastewater purification and solution impurity removal processes.

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