Method for preparing manganese dioxide material by using electrolytic manganese residues and product thereof

Abstract

The invention discloses a method for preparing a manganese dioxide material by using electrolytic manganese residues and a product thereof, and the method comprises the following steps: mixing a sulfuric acid solution and the electrolytic manganese residues, uniformly stirring, drying, roasting, mixing with water, stirring, carrying out solid-liquid separation, mixing the obtained liquid with carbon powder, uniformly stirring, drying, adding ammonium chloride, uniformly stirring, carrying out high-temperature pyrolysis, and calcining. And grinding to obtain calcined slag powder, mixing the calcined slag powder with water, stirring, carrying out solid-liquid separation, and drying the obtained solid part to obtain the manganese dioxide material. According to the method, traditional acid dissolution, extraction and back extraction methods are abandoned, the high-purity manganese dioxide material is prepared from the electrolytic manganese residues through the processes of roasting, acid dissolution, carbon mixing, pyrolysis, calcination and washing innovatively, extraction and back extraction processes are not involved in the preparation process, only sulfuric acid and ammonium chloride serve as needed reagents, the obtaining approach is wide, and the method is suitable for industrial production. The maximum content of the prepared manganese dioxide can reach 97%.

Description

Technical Field

[0001] The invention relates to a method for preparing manganese dioxide material by utilizing electrolytic manganese slag and a product thereof, belonging to the field of resource utilization of solid waste. Background Art

[0002] Electrolytic manganese slag is a by-product produced in the production process of electrolytic manganese, mainly composed of manganese dioxide, lead and other metal oxides. This slag not only contains highly toxic lead elements, but also causes serious environmental pollution if not effectively treated. If electrolytic manganese slag is directly discharged or stored, it will not only occupy a large amount of land resources, but also pollute the soil and groundwater through rainwater leaching and other means. The extraction and reuse of manganese dioxide can significantly reduce the environmental risks of electrolytic manganese slag and reduce the emission of pollutants, which meets the current national requirements for environmental protection and sustainable development. Manganese dioxide rich in electrolytic manganese slag is an important industrial raw material, widely used in batteries, catalysts, magnetic materials and other fields. By extracting manganese dioxide from electrolytic manganese slag, resources can be reused, resource utilization can be improved, production costs can be reduced, and economic benefits can be brought to enterprises.

[0003] The comprehensive utilization of electrolytic manganese slag has promoted the green upgrading and transformation of the electrolytic manganese industry. Through technological innovation and process improvement, waste is converted into valuable resources, which not only enhances the market competitiveness of enterprises, but also promotes the sustainable development of the entire industry. The main components of electrolytic manganese slag include manganese dioxide, lead, iron, silicon and other oxides. The extraction of manganese dioxide from electrolytic manganese slag is mainly based on the principles of chemical reaction and physical separation. Common extraction methods include acid leaching, roasting, microbial method, etc. The environmental impact of using electrolytic manganese slag to prepare manganese dioxide materials is relatively small. On the one hand, it can reduce the emission and stockpile of electrolytic manganese slag: by extracting and reusing the resources in electrolytic manganese slag, its emission and stockpile can be significantly reduced, thereby reducing the risk of environmental pollution; on the other hand, it can reduce energy consumption and pollutant emissions: by adopting energy-saving equipment and optimizing extraction process parameters, energy consumption and pollutant emissions can be reduced, thereby reducing the negative impact on the environment. The industrial application of electrolytic manganese slag to prepare manganese dioxide materials will drive the development of related industrial chains, including deep processing of manganese dioxide and development of downstream products. This will provide more employment opportunities and economic growth points for related industries and promote the development of the regional economy. Summary of the invention

[0004] Purpose of the invention: The technical problem to be solved by the present invention is to provide a method for preparing manganese dioxide material using electrolytic manganese slag and its product.

[0005] Technical solution: To solve the above technical problems, the present invention provides a method for preparing manganese dioxide material by using electrolytic manganese slag, comprising the following steps:

[0006] (1) mixing a sulfuric acid solution and electrolytic manganese slag, stirring evenly, drying, and roasting to obtain an acid-loaded roasting material;

[0007] (2) mixing water and the acid-loaded roasted material in step (1), stirring, and separating the solid from the liquid to obtain an acid leaching liquid;

[0008] (3) mixing the carbon powder into the acid leaching solution in step (2), stirring evenly, drying to obtain a pyrolysis material, mixing the ammonium chloride and the pyrolysis material, stirring evenly, and pyrolyzing at high temperature to obtain a manganese-rich pyrolysis material;

[0009] (4) calcining and grinding the manganese-rich pyrolysis material in step (3) to obtain a calcined slag powder, mixing it with water, stirring it, separating the solid from the liquid, and drying the obtained solid part to obtain a manganese dioxide material.

[0010] Wherein, the calcination temperature in step (1) is 450° C. to 850° C., and the manganese dioxide content of the prepared material is higher than 91%.

[0011] Wherein, the liquid-to-solid ratio of the sulfuric acid solution and the electrolytic manganese slag in step (1) is 0.3-0.6:1 mL / g.

[0012] Wherein, the concentration of the sulfuric acid solution in step (1) is 3 to 15M.

[0013] Wherein, the drying temperature in step (1) is 50 to 250° C., and the drying time is 0.25 to 2.75 hours.

[0014] Wherein, the calcination time in step (1) is 0.5 to 5.5 hours.

[0015] Wherein, the liquid-to-solid ratio of water to acid-loaded roasting material in step (2) is 2 to 8:1 mL / g.

[0016] Wherein, the stirring time in step (2) is 0.5 to 2.5 hours.

[0017] Wherein, the temperature of the high temperature pyrolysis in step (3) is 650-1050°C; and the manganese dioxide content of the prepared materials is higher than 94%.

[0018] Wherein, the solid-to-liquid ratio of the carbon powder and the acid leaching solution in step (3) is 0.2-0.6:1 g / mL.

[0019] Wherein, the mass ratio of ammonium chloride to pyrolysis material in step (3) is 2.5-22.5:100.

[0020] Wherein, the high temperature pyrolysis time in step (3) is 0.5 to 5.5 hours.

[0021] Wherein, the calcination temperature in step (4) is 750-1150° C., and the manganese dioxide content of the prepared material is higher than 96%.

[0022] Wherein, the liquid-to-solid ratio of water to calcined slag powder in step (4) is 2-8:1 mL / g.

[0023] Wherein, the calcination time in step (4) is 1 to 6 hours.

[0024] Wherein, the stirring time in step (4) is 0.5 to 2.5 hours.

[0025] The invention also provides a manganese dioxide material prepared by the method.

[0026] Reaction mechanism:

[0027] During the roasting process, sulfuric acid acts as an oxidant, promoting the reaction of iron and manganese in the electrolytic manganese slag with oxygen to generate high-valent iron and manganese oxides, and further to form sulfates. Mix water and acid-loaded roasting materials, and during the stirring process, iron sulfate, manganese sulfate, aluminum sulfate and a small amount of calcium sulfate, magnesium sulfate, etc. are dissolved in the water to be enriched. Mix carbon powder into the acid leaching solution, and during the stirring process, the sulfate dissolved in the acid solution is adsorbed to the surface and pores of the carbon powder and fixed on the carbon powder during the drying process. The ammonium-loaded pyrolysis preparation is subjected to high-temperature pyrolysis. During the pyrolysis process, ammonium chloride reacts with inorganic iron sulfate, aluminum sulfate, calcium sulfate and other substances on the carbon-based surface to form high saturated chlorides that are volatilized, released and separated. Calcine the manganese-rich pyrolysis material, and under high temperature conditions, manganese salts combine with oxygen to form manganese dioxide. Mix water and calcined slag powder, the soluble salts are dissolved and transferred to water, and the solid part is dried to obtain manganese dioxide material.

[0028] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: the present invention abandons the traditional acid dissolution, extraction and back-extraction methods, but innovatively realizes the preparation of high-purity manganese dioxide material using electrolytic manganese slag through roasting, acid dissolution, carbon mixing, pyrolysis, calcination and washing processes. The preparation process does not involve extraction and back-extraction processes, and the required reagents are only sulfuric acid and ammonium chloride. The acquisition channels are wide, and the maximum content of the prepared manganese dioxide can reach 97%. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a flow chart of the preparation method. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0031] Electrolytic manganese slag: The electrolytic manganese slag is taken from Guizhou Energy Mining Manganese Industry Group Co., Ltd., mainly including 23.52% SO3, 13.17% SiO2, 15.21% CaO, 13.09% Fe2O3, 6.82% Al2O3, 10.21% MnO, 2.96% K2O, 1.55% MgO, 0.86% TiO2 and other components (inevitable impurities and ignition loss).

[0032] Example 1 Effect of calcination temperature on the content of prepared manganese dioxide

[0033] Sulfuric acid solution and electrolytic manganese slag are mixed at a liquid-solid ratio of 0.3:1mL / g, stirred evenly, and dried to obtain acid-loaded manganese slag, wherein the concentration of the sulfuric acid solution is 3M, the drying temperature is 50°C, and the drying time is 0.25 hours. The acid-loaded manganese slag is roasted to obtain acid-loaded roasted material, wherein the roasting temperatures are 375°C, 400°C, 425°C, 450°C, 650°C, 850°C, 875°C, 900°C, and 925°C, and the roasting time is 0.5 hours. Water and acid-loaded roasted material are mixed at a liquid-solid ratio of 2:1mL / g, stirred for 0.5 hours, and the solid-liquid separation is performed to obtain an acid leaching liquid. Carbon powder is mixed into the acid leaching liquid at a solid-liquid ratio of 0.2:1g / mL, stirred evenly, and dried to obtain a pyrolysis stock. Ammonium chloride and pyrolysis stock are mixed at a mass ratio of 2.5:100, stirred evenly, and ammonium-loaded pyrolysis stock is obtained. The ammonium-loaded pyrolysis material is subjected to high-temperature pyrolysis to obtain a manganese-rich pyrolysis material, wherein the pyrolysis temperature is 650°C and the pyrolysis time is 0.5 hour. The manganese-rich pyrolysis material is calcined, and the obtained calcined slag is ground into powder, and then water and the calcined slag powder are mixed according to a liquid-solid ratio of 2:1 mL / g, stirred for 0.5 hours, and the solid-liquid separation is performed. The obtained solid part is dried to obtain a manganese dioxide material, wherein the calcination temperature is 750°C and the calcination time is 1 hour.

[0034] Determination of manganese dioxide content: The manganese dioxide content of the prepared material was determined according to the “Determination of manganese content of manganese ore by potentiometric titration and ammonium ferrous sulfate titration method” (GB / T 1506-2016).

[0035] The experimental results obtained in this example are shown in Table 1.

[0036] Table 1 Effect of calcination temperature on manganese dioxide content of prepared materials

[0037] Calcination temperature Manganese dioxide content Percent Error 375℃ 66.08％ ±0.1％ 400℃ 78.23％ ±0.1％ 425℃ 85.34％ ±0.1％ 450℃ 91.65％ ±0.1％ 650℃ 93.17％ ±0.1％ 850℃ 93.92％ ±0.1％ 875℃ 90.52％ ±0.1％ 900℃ 87.36％ ±0.2％ 925℃ 85.69％ ±0.1％

[0038] It can be seen from Table 1 that when the roasting temperature is less than 450°C (such as in Table 1, when the roasting temperature = 425°C, 400°C, 375°C and lower values ​​not listed in Table 1), the roasting temperature is low, the sulfuric acid solution and the electrolytic manganese slag react insufficiently, resulting in a significant decrease in the manganese dioxide content of the prepared material as the roasting temperature decreases; when the roasting temperature is equal to 450-850°C (such as in Table 1, when the roasting temperature = 450°C, 650°C, 850°C), during the roasting process, sulfuric acid acts as an oxidant to promote the iron and manganese in the electrolytic manganese slag to react with oxygen to generate high-valent iron and manganese oxides, and further form sulfates. Mix water and acid-loaded roasting materials, and during the stirring process, iron sulfate, manganese sulfate, aluminum sulfate and a small amount of calcium sulfate, magnesium sulfate, etc. are dissolved in water, thereby being enriched. Finally, the manganese dioxide content of the prepared materials is higher than 91%. When the roasting temperature is greater than 850°C (such as in Table 1, when the roasting temperature = 875°C, 900°C, 925°C and higher values ​​not listed in Table 1), the roasting temperature is too high, the material is coked and over-burned, which makes the subsequent reaction unbalanced, resulting in the manganese dioxide content of the prepared material decreasing as the roasting temperature further increases. Therefore, in general, combining benefits and costs, when the roasting temperature is equal to 450-850°C, it is most conducive to increasing the manganese dioxide content of the prepared material.

[0039] Example 2 Effect of pyrolysis temperature on manganese dioxide content of prepared materials

[0040] Sulfuric acid solution and electrolytic manganese slag are mixed at a liquid-solid ratio of 0.45:1mL / g, stirred evenly, and dried to obtain acid-loaded manganese slag, wherein the concentration of the sulfuric acid solution is 9M, the drying temperature is 150°C, and the drying time is 1.5 hours. The acid-loaded manganese slag is roasted to obtain an acid-loaded roasted material, wherein the roasting temperature is 850°C and the roasting time is 3 hours. Water and acid-loaded roasted material are mixed at a liquid-solid ratio of 5:1mL / g, stirred for 1.5 hours, and the solid-liquid separation is performed to obtain an acid leaching liquid. Carbon powder is mixed into the acid leaching liquid at a solid-liquid ratio of 0.4:1g / mL, stirred evenly, and dried to obtain a pyrolysis material. Ammonium chloride and pyrolysis material are mixed at a mass ratio of 12.5:100, stirred evenly, and ammonium-loaded pyrolysis material is obtained. The ammonium-loaded pyrolysis material is subjected to high-temperature pyrolysis to obtain a manganese-rich pyrolysis material, wherein the pyrolysis temperature is 500°C, 550°C, 600°C, 650°C, 850°C, 1050°C, 1100°C, 1150°C, and 1200°C, and the pyrolysis time is 3 hours. The manganese-rich pyrolysis material is calcined, and the obtained calcined slag is ground into powder, and then water and the calcined slag powder are mixed according to a liquid-solid ratio of 5:1 mL / g, stirred for 1.5 hours, and the solid-liquid separation is performed. The obtained solid part is dried to obtain a manganese dioxide material, wherein the calcination temperature is 950°C and the calcination time is 3.5 hours.

[0041] The determination of manganese dioxide content is the same as in Example 1. The experimental results obtained in this example are shown in Table 2.

[0042] Table 2 Effect of pyrolysis temperature on manganese dioxide content of prepared materials

[0043] Pyrolysis temperature Manganese dioxide content Percent Error 500℃ 75.37％ ±0.2％ 550℃ 80.14％ ±0.1％ 600℃ 88.52％ ±0.1％ 650℃ 94.06％ ±0.1％ 850℃ 95.48％ ±0.1％ 1050℃ 96.11％ ±0.1％ 1100℃ 92.85％ ±0.1％ 1150℃ 90.25％ ±0.1％ 1200℃ 87.44％ ±0.1％

[0044] As can be seen from Table 2, when the pyrolysis temperature is less than 650°C (as in Table 2, when the pyrolysis temperature = 600°C, 550°C, 500°C and lower values ​​not listed in Table 2), the pyrolysis temperature is low, and the pyrolysis reaction of the ammonium-loaded pyrolysis preparation is insufficient, resulting in a significant decrease in the manganese dioxide content of the prepared material as the pyrolysis temperature decreases; when the pyrolysis temperature is equal to 650-1050°C (as in Table 2, when the pyrolysis temperature = 650°C, 850°C, 1050°C), the ammonium-loaded pyrolysis preparation is subjected to high-temperature pyrolysis, and during the pyrolysis process, on the carbon-based surface, ammonium chloride reacts with inorganic ferrous sulfate, aluminum sulfate, calcium sulfate and other substances to form a high saturated autoclave chloride to volatilize, release and separate. Finally, the manganese dioxide content of the prepared material is higher than 94%. When the pyrolysis temperature is greater than 1050°C (such as in Table 2, when the pyrolysis temperature = 1100°C, 1150°C, 1200°C and higher values ​​not listed in Table 2), the pyrolysis temperature is too high, the material reaction is unbalanced, and the manganese dioxide content of the prepared material decreases as the pyrolysis temperature further increases. Therefore, in general, combining benefits and costs, when the pyrolysis temperature is equal to 650-1050°C, it is most conducive to increasing the manganese dioxide content of the prepared material.

[0045] Example 3 Effect of calcination temperature on manganese dioxide content of prepared materials

[0046] Sulfuric acid solution and electrolytic manganese slag are mixed at a liquid-solid ratio of 0.6:1mL / g, stirred evenly, and dried to obtain acid-loaded manganese slag, wherein the concentration of the sulfuric acid solution is 15M, the drying temperature is 250°C, and the drying time is 2.75 hours. The acid-loaded manganese slag is roasted to obtain an acid-loaded roasted material, wherein the roasting temperature is 850°C and the roasting time is 5.5 hours. Water and acid-loaded roasted material are mixed at a liquid-solid ratio of 8:1mL / g, stirred for 2.5 hours, and the solid-liquid separation is performed to obtain an acid leaching liquid. Carbon powder is mixed into the acid leaching liquid at a solid-liquid ratio of 0.6:1g / mL, stirred evenly, and dried to obtain a pyrolysis material. Ammonium chloride and pyrolysis material are mixed at a mass ratio of 22.5:100, stirred evenly, and ammonium-loaded pyrolysis material is obtained. The ammonium-loaded pyrolysis material is subjected to high-temperature pyrolysis to obtain a manganese-rich pyrolysis material, wherein the pyrolysis temperature is 1050°C and the pyrolysis time is 5.5 hours. The manganese-rich pyrolysis material is calcined, and the obtained calcined slag is ground into powder. Water and the calcined slag powder are mixed according to a liquid-solid ratio of 8:1 mL / g, stirred for 2.5 hours, and the solid-liquid separation is performed. The obtained solid part is dried to obtain a manganese dioxide material, wherein the calcination temperature is 600°C, 650°C, 700°C, 750°C, 950°C, 1150°C, 1200°C, 1250°C, and 1300°C, and the calcination time is 6 hours.

[0047] The determination of manganese dioxide content is the same as in Example 1. The experimental results obtained in this example are shown in Table 3.

[0048] Table 3 Effect of calcination temperature on manganese dioxide content of prepared materials

[0049] Calcination temperature Manganese dioxide content Percent Error 600℃ 82.49％ ±0.2％ 650℃ 87.66％ ±0.2％ 700℃ 93.21％ ±0.1％ 750℃ 96.29％ ±0.1％ 950℃ 97.32％ ±0.1％ 1150℃ 97.95％ ±0.1％ 1200℃ 95.04％ ±0.2％ 1250℃ 93.37％ ±0.1％ 1300℃ 90.29％ ±0.1％

[0050] It can be seen from Table 3 that when the calcination temperature is less than 750°C (such as in Table 3, when the calcination temperature = 700°C, 650°C, 600°C and lower values ​​not listed in Table 3), the calcination temperature is low and the calcination is insufficient, resulting in a significant decrease in the manganese dioxide content of the prepared material as the calcination temperature decreases; when the calcination temperature is equal to 750-1150°C (such as in Table 3, when the calcination temperature = 750°C, 950°C, 1150°C), the manganese-rich pyrolysis material is calcined, and under high temperature conditions, manganese salts combine with oxygen to form manganese dioxide. Mix water and calcined slag powder, dissolve the soluble salt and transfer it to water, and dry the solid part to obtain a manganese dioxide material. Finally, the manganese dioxide content of the prepared materials is higher than 96%. When the calcination temperature is greater than 1150°C (such as in Table 3, when the calcination temperature is 1200°C, 1250°C, 1300°C and higher values ​​not listed in Table 3), the calcination temperature is too high, the material reaction is unbalanced, and the manganese dioxide content of the prepared material decreases as the calcination temperature further increases. Therefore, in general, combining benefits and costs, when the calcination temperature is equal to 750-1150°C, it is most conducive to increasing the manganese dioxide content of the prepared material.

[0051] Comparative Example Effect of Different Comparative Processes on the Manganese Dioxide Content of the Prepared Materials

[0052] The process of the present invention is as follows: sulfuric acid solution and electrolytic manganese slag are mixed according to a liquid-solid ratio of 0.6:1mL / g, stirred evenly, and dried to obtain acid-loaded manganese slag, wherein the concentration of the sulfuric acid solution is 15M, the drying temperature is 250°C, and the drying time is 2.75 hours. The acid-loaded manganese slag is roasted to obtain an acid-loaded roasted material, wherein the roasting temperature is 850°C and the roasting time is 5.5 hours. Water and acid-loaded roasted material are mixed according to a liquid-solid ratio of 8:1mL / g, stirred for 2.5 hours, and solid-liquid separation is performed to obtain an acid leaching liquid. Carbon powder is mixed into the acid leaching liquid according to a solid-liquid ratio of 0.6:1g / mL, stirred evenly, and dried to obtain a pyrolysis material. Ammonium chloride and pyrolysis material are mixed according to a mass ratio of 22.5:100, stirred evenly, and ammonium-loaded pyrolysis material is obtained. The ammonium-loaded pyrolysis material is subjected to high-temperature pyrolysis to obtain a manganese-rich pyrolysis material, wherein the pyrolysis temperature is 1050°C and the pyrolysis time is 5.5 hours. The manganese-rich pyrolysis material is calcined, and the obtained calcined slag is ground into powder. Then water and the calcined slag powder are mixed according to a liquid-solid ratio of 8:1 mL / g, stirred for 2.5 hours, and the solid-liquid separation is performed. The obtained solid part is dried to obtain a manganese dioxide material, wherein the calcination temperature is 1150°C and the calcination time is 6 hours.

[0053] Comparative process 1: Roast the electrolytic manganese slag to obtain a roasting material, wherein the roasting temperature is 850°C and the roasting time is 5.5 hours. Mix water and roasting material at a liquid-solid ratio of 8:1mL / g, stir for 2.5 hours, separate the solid and liquid, and the obtained liquid is an extract. Mix carbon powder into the extract at a solid-liquid ratio of 0.6:1g / mL, stir evenly, and dry to obtain a pyrolysis material. Mix ammonium chloride and pyrolysis material at a mass ratio of 22.5:100, stir evenly, and obtain an ammonium-loaded pyrolysis material. The ammonium-loaded pyrolysis material is subjected to high-temperature pyrolysis to obtain a manganese-rich pyrolysis material, wherein the pyrolysis temperature is 1050°C and the pyrolysis time is 5.5 hours. The manganese-rich pyrolysis material is calcined, and the obtained calcined slag is ground into powder. Then water and the calcined slag powder are mixed according to a liquid-solid ratio of 8:1 mL / g, stirred for 2.5 hours, and the solid-liquid separation is performed. The obtained solid part is dried to obtain a manganese dioxide material, wherein the calcination temperature is 1150°C and the calcination time is 6 hours.

[0054] Comparative process 2: Mix sulfuric acid solution and electrolytic manganese slag at a liquid-solid ratio of 0.6:1mL / g, stir evenly, and dry to obtain acid-loaded manganese slag, wherein the concentration of sulfuric acid solution is 15M, the drying temperature is 250℃, and the drying time is 2.75 hours. Roast the acid-loaded manganese slag to obtain acid-loaded roasting material, wherein the roasting temperature is 850℃ and the roasting time is 5.5 hours. Mix water and acid-loaded roasting material at a liquid-solid ratio of 8:1mL / g, stir for 2.5 hours, separate the solid and liquid, and the obtained liquid is an acid leaching liquid. Mix carbon powder into the acid leaching liquid at a solid-liquid ratio of 0.6:1g / mL, stir evenly, and dry to obtain a pyrolysis preparation. The pyrolysis preparation is subjected to high-temperature pyrolysis to obtain a manganese-rich pyrolysis material, wherein the pyrolysis temperature is 1050℃ and the pyrolysis time is 5.5 hours. The manganese-rich pyrolysis material is calcined, and the obtained calcined slag is ground into powder. Then water and the calcined slag powder are mixed according to a liquid-solid ratio of 8:1 mL / g, stirred for 2.5 hours, and the solid-liquid separation is performed. The obtained solid part is dried to obtain a manganese dioxide material, wherein the calcination temperature is 1150°C and the calcination time is 6 hours.

[0055] The determination of manganese dioxide content is the same as in Example 1. The experimental results obtained in this example are shown in Table 4.

[0056] Table 4 Effect of different comparative processes on the manganese dioxide content of the prepared materials

[0057] Process Type Manganese dioxide content Percent Error Process of the present invention 97.95％ ±0.2％ Comparison process 1 41.17％ ±0.2％ Comparison process 2 52.78％ ±0.1％

[0058] It can be seen from Table 4 that the manganese dioxide content prepared by the process of the present invention is significantly higher than that of comparative process 1 and comparative process 2, and higher than the sum of the two.

Claims

1. A method for preparing manganese dioxide material using electrolytic manganese slag, characterized in that: The following steps are involved: (1) mixing a sulfuric acid solution and electrolytic manganese slag, stirring evenly, drying, and roasting to obtain an acid-loaded roasted material; the roasting temperature is 450° C. to 850° C.; (2) mixing water and the acid-loaded roasted material in step (1), stirring, and separating the solid from the liquid to obtain an acid leaching liquid; (3) mixing the carbon powder into the acid leaching solution in step (2), stirring evenly, drying to obtain a pyrolysis material, mixing the ammonium chloride and the pyrolysis material, stirring evenly, and pyrolyzing at high temperature to obtain a manganese-rich pyrolysis material; the temperature of the high-temperature pyrolysis is 650-1050° C.; (4) calcining and grinding the manganese-rich pyrolysis material in step (3) to obtain a calcined slag powder, mixing it with water, stirring it, separating the solid from the liquid, and drying the obtained solid part to obtain a manganese dioxide material, wherein the calcination temperature is 750 to 1150°C.

2. The method according to claim 1, characterized in that: The liquid-to-solid ratio of the sulfuric acid solution to the electrolytic manganese slag in step (1) is 0.3-0.6:1 mL / g.

3. The method according to claim 1, characterized in that: The concentration of the sulfuric acid solution in step (1) is 3 to 15 M.

4. The method according to claim 1, characterized in that: The drying temperature in step (1) is 50 to 250° C., and the drying time is 0.25 to 2.75 hours.

5. The method according to claim 1, characterized in that: The calcination time in step (1) is 0.5 to 5.5 hours.

6. The method according to claim 1, characterized in that: The liquid-to-solid ratio of water to the acid-loaded roasting material in step (2) is 2-8:1 mL / g.

7. The method according to claim 1, characterized in that: The solid-to-liquid ratio of the carbon powder to the acid leaching solution in step (3) is 0.2-0.6:1 g / mL.

8. The method according to claim 1, characterized in that: The mass ratio of ammonium chloride to pyrolysis materials in step (3) is 2.5 to 22.5:

100.

9. The method according to claim 1, characterized in that: The liquid-to-solid ratio of water to calcined slag powder in step (4) is 2-8:1 mL / g.

10. A manganese dioxide material prepared by the method according to any one of claims 1 to 9.

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