Production method for co-production of magnesium sulfate and manganese sulfate

Abstract

The invention relates to a production method for co-production of magnesium sulfate and manganese sulfate. The method has obvious advantages, uses magnesium sulfite waste as a raw material, cooperates with magnesium sulfate crystallization mother liquor circulation, greatly improves the resource utilization rate, and reduces the production cost. The manganese oxide mineral powder and the concentrated sulfuric acid are accurately proportioned according to a chemical equation in the reaction process, the reaction is efficiently carried out, the generation rate is improved, the sulfur dioxide generated by the reaction is absorbed and then manganese is recovered, and the resource waste and pollution are reduced. The O / A ratio is reasonably controlled through the extraction section, and precise separation of magnesium sulfate and manganese sulfate is achieved. Magnesium sulfate crystallization can select a cooling crystallization or acidification neutralization mode, and products are diversified; and manganese sulfate is subjected to multi-stage oil removal to ensure high purity. Tail gas treatment in the production process is proper, mother liquor is recycled, the environment-friendly and energy-saving targets are achieved, economic benefits and environmental benefits are considered, and sustainable development of the chemical industry is powerfully promoted.

Description

Technical Field

[0001] The present invention relates to a production method for co-producing magnesium sulfate and manganese sulfate. Background Art

[0002] In the field of industrial production, the treatment and utilization of magnesium sulfite waste residue and manganese oxide ore have always been problems to be solved urgently. As waste from power plant desulfurization, if the magnesium sulfite waste residue is not comprehensively utilized, it will not only occupy a large amount of land resources, but also the harmful substances contained therein will cause serious pollution to soil, water bodies and air, and at the same time, it is also a great waste of mineral resources. Due to its own characteristics, manganese oxide ore is insoluble in dilute sulfuric acid. If leaching is to be achieved, a reducing agent needs to be added, which undoubtedly increases the production cost. When the magnesium sulfite waste residue is acidolyzed, sulfurous acid and highly reducing sulfur dioxide are generated. If not recycled, it will also lead to environmental pollution and resource waste. Traditional methods for producing magnesium sulfate and manganese sulfate often cannot effectively solve the above problems, and have disadvantages such as complex processes, high costs, and serious environmental pollution, and are difficult to meet the requirements of sustainable development. Summary of the Invention

[0003] The purpose of the present invention is to provide a production method for co-producing magnesium sulfate and manganese sulfate to solve the problems raised in the above background art.

[0004] To solve the above technical problems, the technical solution provided by the present invention is: A production method for co-producing magnesium sulfate and manganese sulfate, comprising the following steps:

[0005] Characterized in that it comprises the following steps:

[0006] 1) Premixing and pulping process of magnesium sulfite and manganese oxide ore powder: In a dispersion tank, use magnesium sulfate crystallization mother liquor to pulp and crush the magnesium sulfite waste residue. After starting the stirring of the dispersion tank, add it to the dispersion tank for pulping according to the mass ratio of magnesium sulfite hexahydrate to magnesium sulfate crystallization mother liquor of about 1 - 10:10:1, and then pump it into the reaction tank;

[0007] 2) Reaction process: Add magnesium sulfate crystallization mother liquor to the reaction tank and start stirring, add manganese oxide ore powder, and add equimolar manganese oxide ore powder according to the stoichiometric ratio of the chemical equation MgSO3·6H2O + MnO2 + H2SO4 → MgSO4·7H2O + MnSO4·H2O; The materials of the premixing process are in accordance with the molar ratio of the chemical reaction equation and are obtained by converting according to the contents of magnesium sulfite and manganese oxide ore; For example: Each time, add 31 tons of magnesium sulfite hexahydrate accounting for 80% of the total amount to each reaction tank and about 60m of magnesium sulfate crystallization mother liquor 3The mixed slurry is pumped into the reaction tank, and 21 tons of manganese oxide ore powder containing 30% manganese is added under stirring conditions; 98% concentrated sulfuric acid is metered and added dropwise per hour. After the addition is completed, the pH value at the reaction end point is adjusted and controlled between 5.5 and 6 with magnesium sulfite slurry, and stirring is continued for 60 min before filtration; most of the sulfur dioxide generated during the reaction is absorbed by the manganese oxide in the solution, and a small amount enters the tail gas absorption system for secondary absorption with manganese oxide slurry. The manganese oxide ore slurry after absorbing sulfur dioxide is returned to the leaching section to recover manganese;

[0008] 3) Pressure filtration process: The reacted material is transferred to the pressure filtration tank, and the material is pumped into the reaction hydraulic filter press for filtration under stirring conditions by a plate and frame feed pump to remove the insoluble matter in the raw material; the pressure filtration mother liquor enters the deep purification tank, and the solid is washed with water and sold as a gel material; manganese oxide powder is added to the filtrate in the deep purification tank, heated to 70 °C and reacted for 1 hour under stirring, and the pH is adjusted to 5.5 - 6.0 with magnesium sulfite slurry and magnesium sulfate mother liquor. After the reaction is completed, it is pumped into the purification pressure filtration plate and frame by a purification pressure filtration pump for solid-liquid separation. The mother liquor enters the purified filtrate tank, and the filter residue is returned to the reaction tank for reuse;

[0009] 4) Extraction section: The purified liquid in the filtrate tank enters the extraction system through a security filter, and an extractant and the leached and filtered liquid are added according to a certain O / A; for example, the post-leaching liquid is added at a flow rate of 3.6 m 3 per hour, and the organic phase is added according to the ratio of magnesium sulfate solution to extractant O / A of 5:1; the raffinate of the mixed manganese sulfate and magnesium sulfate liquid after extraction is pumped into the magnesium sulfate pre-crystallization liquid storage tank. After the organic phase is loaded with manganese, it is back-extracted with dilute sulfuric acid containing 20 - 30% sulfuric acid, and the back-extracted organic phase is pumped into the manganese sulfate high-temperature pre-crystallization liquid storage tank;

[0010] 5) Magnesium sulfate crystallization process: The magnesium sulfate raffinate is subjected to an oil removal process (oil removal can also be not used). When the oil content is below 15 ppm, it enters the magnesium sulfate cooling crystallization tank, and then crystallization, separation and packaging are carried out;

[0011] 6) Manganese sulfate crystallization process: The back-extracted manganese sulfate solution is pumped into an oil remover. After three-stage oil removal, when the oil content in the manganese sulfate saturated solution reaches below 10 ppm, it is pumped into a high-temperature crystallization kettle, heated to 180 - 200 °C under stirring, stirred and crystallized for 20 min and then discharged. The manganese sulfate after high-temperature filtration is sent to a dryer for drying and then packaged into ton bags for sale, and the crystallization mother liquor is returned to the process of preparing 20 - 30% sulfuric acid back-extraction liquid.

[0012] Preferably, magnesium sulfite is reacted with manganese oxide ore solution or water, stirred evenly, and then sulfuric acid is added dropwise. The sulfur dioxide generated during the reaction is absorbed by manganese oxide ore powder and converted into manganese sulfate. The filtrate after the reaction of magnesium sulfite, manganese oxide ore and sulfuric acid is separated into magnesium sulfate and manganese sulfate by extraction. In the said reaction process, the tail gas is absorbed by manganese dioxide ore powder slurry. After the absorption is saturated, the manganese dioxide slurry goes to the reaction tank to recover manganese sulfate. The concentration of magnesium sulfate in the leaching solution can be cooled to obtain clean magnesium sulfate heptahydrate.

[0013] Preferably, during the crystallization process of magnesium sulfate, magnesium sulfate heptahydrate is obtained by cooling crystallization, or after acid precipitation with concentrated sulfuric acid to obtain magnesium sulfate monohydrate, magnesium carbonate, magnesium oxide, magnesium hydroxide, etc. or other magnesium compounds are used to neutralize the remaining acid to produce magnesium sulfate monohydrate.

[0014] Preferably, the extraction method for the filtrate after the reaction of magnesium sulfite and manganese oxide ore powder with sulfuric acid is as follows: when the extractant extracts manganese, magnesium sulfite or magnesium oxide saponifier is used or the pH value is adjusted to extract manganese to separate manganese from magnesium; when the extractant extracts magnesium, manganese carbonate or manganese monoxide is used as the saponifier or the pH value is adjusted to extract magnesium to separate manganese from magnesium.

[0015] The advantages of the present invention are as follows: Comprehensive utilization of raw materials: Innovatively using magnesium sulfite waste as a production raw material not only solves the problem of treating magnesium sulfite waste, reduces the risk of environmental pollution, but also turns waste into treasure, greatly improves the resource utilization rate and reduces the production cost. At the same time, the recycling of the magnesium sulfate crystallization mother liquor reduces the input of new raw materials and further improves the raw material utilization efficiency.

[0016] Efficient reaction conversion: In the reaction process, by accurately adding manganese oxide ore powder and concentrated sulfuric acid according to the chemical equation ratio, the reaction can proceed efficiently and fully, improving the formation rate of the target products magnesium sulfate and manganese sulfate. Moreover, most of the sulfur dioxide generated during the reaction is absorbed by manganese oxide in the solution, and a small amount enters the tail gas absorption system and can also be secondarily absorbed by the manganese oxide slurry and returned to the leaching section to recover manganese, reducing the waste of sulfur resources and environmental pollution.

[0017] Product separation and purification: The extraction section is used to effectively separate magnesium sulfate and manganese sulfate. By reasonably controlling the O / A ratio and adding the extractant, the separation of manganese and magnesium can be accurately achieved. During the crystallization process of magnesium sulfate, magnesium sulfate heptahydrate can be obtained by cooling crystallization according to requirements, or magnesium sulfate monohydrate can be produced by adding concentrated sulfuric acid for acid precipitation and neutralizing the remaining acid, etc. The product forms are diverse, meeting different market demands. During the crystallization process of manganese sulfate, through multi-stage oil removal treatment, the high purity of the product is guaranteed and the product quality is improved.

[0018] Process environmental protection and energy conservation: During the entire production process, the tail gas treatment system effectively reduces the emission of harmful gas sulfur dioxide, meeting environmental protection requirements. The mother liquor in each process is recycled, reducing wastewater discharge and simultaneously lowering energy consumption, achieving the dual goals of environmental protection and energy conservation.

[0019] Equal emphasis on economic and environmental benefits: While realizing the co-production of magnesium sulfate and manganese sulfate, this production method takes into account both economic and environmental benefits. It not only reduces production costs, improves the profitability of enterprises, but also reduces the negative impact on the environment, contributing to the sustainable development of the chemical industry. Brief description of the drawings

[0020] Figure 1 is the process flow chart of the present invention. Detailed implementation manners

[0021] For the purposes of the following detailed description, it should be understood that the present invention may employ various alternative variations and step sequences, unless expressly specified to the contrary. Additionally, except in any operating examples, or otherwise indicated, all numbers expressing quantities of ingredients, etc. used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0022] Although the numerical ranges and parameters setting forth the broad scope of the present invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. However, any numerical value inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0023] Furthermore, it should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of "1 to 10" is intended to include all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.

[0024] Example 1

[0025] Premixing and pulping process of magnesium sulfite and manganese oxide ore powder: Add an appropriate amount of magnesium sulfate crystallization mother liquor into the dispersion tank, put the magnesium sulfite waste into it for pulping and pulverization, and start the stirring device. According to the ratio of 80% magnesium sulfite hexahydrate to magnesium sulfate crystallization mother liquor of 1:2 in mass ratio, add the corresponding amount of 80% magnesium sulfite hexahydrate and continue pulping, and then pump it into the reaction tank after completion.

[0026] Reaction process: Add 30 m 3 magnesium sulfate crystallization mother liquor into the reaction tank and start stirring. Add manganese oxide ore powder. According to the stoichiometric balance of the chemical equation MgSO3·6H2O + MnO2 + H2SO4 → MgSO4·7H2O + MnSO4·H2O, add an equimolar amount of manganese oxide ore powder. Then, pump the mixed slurry of the materials from the premixing process, i.e., 31 tons of 80% magnesium sulfite hexahydrate and 60 m 3 magnesium sulfate crystallization mother liquor into the reaction tank, and then add 21 tons of manganese oxide ore powder containing 30% manganese. Dropwise add 98% concentrated sulfuric acid at a rate of per hour. After the addition is completed, adjust the pH value of the reaction end point to 5.5 with magnesium sulfite slurry, continuously stir for 60 min and then filter. Most of the sulfur dioxide generated by the reaction is absorbed by manganese oxide in the solution, and a small amount enters the tail gas absorption system for secondary absorption with manganese oxide slurry.

[0027] Filter press process: Transfer the materials after the reaction to the filter press tank, and pump them into the reaction hydraulic filter press for filtration under stirring to remove insoluble substances. The filter press mother liquor enters the deep purification tank, and the solid is washed with water and sold as gel material. Add 1 ton of manganese oxide powder to the filtrate in the deep purification tank, stir and heat to 70 °C for 1 hour, adjust the pH to 5.5 with magnesium sulfite slurry and magnesium sulfate mother liquor. After the reaction is completed, pump it into the purification filter press plate and frame through the purification filter press pump for solid-liquid separation. The mother liquor enters the purified filtrate tank, and the filter residue returns to the reaction tank.

[0028] Extraction section: The purified liquid in the filtrate tank enters the extraction system through the security filter and is added at a flow rate of 3.6 m 3 per hour. The organic phase is added according to the ratio of magnesium sulfate solution to extractant O / A of 5:1. The raffinate of the manganese sulfate and magnesium mixture after extraction is pumped into the magnesium sulfate pre-crystallization liquid storage tank. After the organic phase is loaded with manganese, it is back-extracted with dilute sulfuric acid containing 20% sulfuric acid, and the back-extracted organic phase is pumped into the manganese sulfate high-temperature pre-crystallization liquid storage tank.

[0029] Magnesium sulfate crystallization process: The magnesium sulfate raffinate is degreased by ultrasonic wave. When the oil content drops below 15 ppm, it is sent to the magnesium sulfate cooling crystallization tank for crystallization, separation and packaging.

[0030] Manganese sulfate crystallization process: The manganese sulfate solution after back-extraction is pumped into the oil remover. After three-stage oil removal, when the oil content in the manganese sulfate saturated solution reaches below 10 ppm, it is pumped into the high-temperature crystallization kettle, heated to 180 °C under stirring, stirred and crystallized for 20 min and then discharged. The manganese sulfate after high-temperature filtration is sent to the dryer for drying and then packaged into ton bags for sale. The crystallization mother liquor returns to the process of preparing 20% sulfuric acid back-extraction liquid.

[0031] Example 2

[0032] Premixing and pulping process of magnesium sulfite and manganese oxide ore powder: The operation is the same as that in Example 1.

[0033] Reaction process: Add magnesium sulfate crystallization mother liquor to the reaction tank. After starting stirring, add manganese oxide ore powder, and add equimolar manganese oxide ore powder according to the chemical equation ratio. Add the materials from the premixing process (31 tons of 80% magnesium sulfite hexahydrate and 60 m 3 mixed slurry of magnesium sulfate crystallization mother liquor) and 21 tons of manganese oxide ore powder containing 30% manganese. Meter and drip 98% concentrated sulfuric acid per hour. After the dripping is completed, adjust the pH value of the reaction end point to 5.7 with magnesium sulfite slurry, continue stirring for 60 min and then filter. The tail gas treatment method is the same as that in Example 1.

[0034] Filter press process: The operation is the same as that in Example 1.

[0035] Extraction section: The purified post-liquid enters the extraction system at a flow rate of 3.6 m 3 per hour. The O / A ratio of the organic phase magnesium sulfate solution to the extractant is 5:1. After extraction, the raffinate is pumped into the magnesium sulfate pre-crystallization liquid storage tank. After the organic phase is loaded with manganese, it is back-extracted with dilute sulfuric acid containing 25% sulfuric acid, and the back-extracted organic phase is pumped into the manganese sulfate high-temperature pre-crystallization liquid storage tank.

[0036] Magnesium sulfate crystallization process: The magnesium sulfate raffinate is degreased by ultrasonic wave until the oil content is below 15 ppm, and then enters the magnesium sulfate cooling crystallization tank for crystallization, separation and packaging.

[0037] Manganese sulfate crystallization process: The manganese sulfate solution is degreased in three stages until the oil content is below 10 ppm, pumped into the high-temperature crystallization kettle, heated to 190 °C under stirring, stirred and crystallized for 20 min and then discharged. The subsequent operations are the same as those in Example 1.

[0038] Example 3

[0039] Premixing and pulping process of magnesium sulfite and manganese oxide ore powder: Repeat the steps of Example 1.

[0040] Reaction process: In the operation of the reaction tank, add materials and stir, add manganese oxide ore powder according to stoichiometry. After adding the premixed materials and specific manganese oxide ore powder, drip 98% concentrated sulfuric acid per hour. After the dripping is completed, adjust the pH value to 6 with magnesium sulfite slurry, stir for 60 min and then filter. The tail gas treatment is the same as before.

[0041] Filter press process: Keep the same operation as in Example 1.

[0042] Extraction section: The purified post-liquid enters the extraction system at a flow rate of 3.6 m 3 per hour, and the organic phase ratio remains unchanged. After extraction, the raffinate is pumped into the magnesium sulfate pre-crystallization liquid storage tank. After the organic phase is loaded with manganese, it is back-extracted with dilute sulfuric acid containing 30% sulfuric acid, and the back-extracted organic phase is pumped into the manganese sulfate high-temperature pre-crystallization liquid storage tank.

[0043] Magnesium sulfate crystallization process: After the magnesium sulfate raffinate reaches the standard of ultrasonic degreasing, it enters the cooling crystallization tank for subsequent treatment.

[0044] Manganese sulfate crystallization process: After the manganese sulfate solution is degreased in three stages, it is pumped into a high-temperature crystallization kettle, heated to 200 °C, stirred for crystallization for 20 min, and the subsequent treatment is the same as that in Example 1.

[0045] Example 4

[0046] Premixing and pulping process of magnesium sulfite and manganese oxide ore powder: The same as in Example 1.

[0047] Reaction process: During the operation of the reaction tank, various materials are added and stirred. Manganese oxide ore powder is added according to the equation ratio. Premixed materials and 21 tons of manganese oxide ore powder containing 30% manganese are added. Concentrated sulfuric acid is added dropwise, and the pH value is adjusted to 5.6. After stirring for 60 min, filtration is carried out, and the tail gas treatment is the same as before. In addition, in the reaction process, the tail gas is absorbed by the manganese dioxide ore powder slurry, and the manganese dioxide slurry after absorption saturation goes to the reaction tank to recover manganese sulfate.

[0048] Filter press process: The same as in Example 1.

[0049] Extraction section: The same as in Example 3.

[0050] Magnesium sulfate crystallization process: During the magnesium sulfate crystallization process, ultrasonic waves are used to degrease the magnesium sulfate raffinate, and the remaining operations are the same as in Example 3.

[0051] Manganese sulfate crystallization process: The same as in Example 3.

[0052] Example 5

[0053] Premixing and pulping process of magnesium sulfite and manganese oxide ore powder: The operation method is the same as in Example 1.

[0054] Reaction process: Add materials and stir, add manganese oxide ore powder according to the chemical equation, add premixed materials and manganese oxide ore powder, add concentrated sulfuric acid dropwise, adjust the pH value to 5.8, stir for 60 min and then filter, and the tail gas treatment is the same as in Example 4.

[0055] Filter press process: The same as the steps in Example 1.

[0056] Extraction section: Operations such as the flow rate of the purified post-liquid and the organic phase ratio are the same as in Example 3.

[0057] Magnesium sulfate crystallization process: The magnesium sulfate raffinate is degreased by ultrasonic waves, and after degreasing, it enters the cooling crystallization tank for crystallization, separation and packaging, and other operations are the same as in Example 4.

[0058] Manganese sulfate crystallization process: Operations such as three-stage degreasing, crystallization, and drying and packaging of the manganese sulfate solution are the same as in Example 4.

[0059] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. A method for producing magnesium sulfate and manganese sulfate, characterized in that: The following steps are involved: It is characterized by comprising the following steps: 1) Magnesium sulfite and manganese oxide ore powder premixing and pulping process: In a dispersion tank, magnesium sulfate crystal mother liquor is used to pulp and crush magnesium sulfite waste. After starting the dispersion tank stirring, magnesium sulfite hexahydrate and magnesium sulfate crystal mother liquor are added to the dispersion tank in a mass ratio of about 1-10:10:1 for pulping, and then pumped into the reaction tank; 2) Reaction process: add magnesium sulfate crystallization mother liquor to the reaction tank and start stirring, add manganese oxide ore powder, and add equimolar manganese oxide ore powder according to the chemical equation of MgSO3·6H2O+MnO2+H2SO4→MgSO4·7H2O+MnSO4·H2O; convert the materials in the premixing process according to the molar ratio of the chemical reaction equation and the content of magnesium sulfite and manganese oxide ore; for example: Each time, add 31 tons of 80% magnesium sulfite hexahydrate and about 60m3 of magnesium sulfate crystallization mother liquor to each reaction tank. 3 The mixed slurry is pumped into the reaction tank, and 21 tons of manganese oxide ore powder containing 30% manganese is added under stirring conditions; 98% concentrated sulfuric acid is added dropwise according to the hourly metering. After the addition is completed, the pH value of the reaction end point is adjusted to be between 5.5 and 6 with magnesium sulfite slurry, and the mixture is stirred for 60 minutes before filtering; most of the sulfur dioxide generated during the reaction is absorbed by the manganese oxide in the solution, and a small amount enters the tail gas absorption system for secondary absorption with manganese oxide slurry. The manganese oxide slurry after absorbing the sulfur dioxide is returned to the leaching section to recover manganese; 3) Filter pressing process: the materials after the reaction are transferred to the filter press tank, and the materials are pumped into the reaction hydraulic filter by the plate and frame feed pump under stirring conditions for filtration to remove the insoluble matter in the raw materials; the filter press mother liquor enters the deep purification tank, and the solid is washed with water and sold as a gel material; manganese oxide powder is added to the filtrate of the deep purification tank, heated to 70°C for reaction for 1 hour under stirring, and the pH is adjusted to 5.5-6.0 with magnesium sulfite slurry and magnesium sulfate mother liquor. After the reaction is completed, it is pumped into the purification filter press plate frame by the purification filter press pump for solid-liquid separation, and the mother liquor enters the purified filtrate tank, and the filter residue is returned to the reaction tank for reuse; 4) Extraction section: The purified liquid in the filtrate tank enters the extraction system through the security filter, and the extractant is added and the filtered liquid is leached according to a certain O / A; for example: the leached liquid is 3.6m 3 The organic phase is added at a flow rate of 5:1 per hour, and the organic phase is added at a ratio of 5:1 between the magnesium sulfate solution and the extractant O / A; the raffinate of the manganese sulfate and magnesium sulfate mixed solution after extraction is pumped into the magnesium sulfate pre-crystallization liquid storage tank, and the organic phase is loaded with manganese and then stripped with dilute sulfuric acid containing 20-30% sulfuric acid, and the organic phase after stripping is pumped into the manganese sulfate high-temperature crystallization pre-liquid storage tank; 5) Magnesium sulfate crystallization process: The magnesium sulfate raffinate is subjected to oil removal process (or oil removal is not required), and when the oil content is below 15ppm, it enters the magnesium sulfate cooling crystallization tank, and then crystallizes, separates and packages; 6) Manganese sulfate crystallization process: The manganese sulfate solution after stripping is pumped into the deoiler and deoiled at three stages. When the oil content of the saturated manganese sulfate solution is below 10 ppm, it is pumped into a high-temperature crystallization kettle and heated to 180-200° C. under stirring. After stirring and crystallizing for 20 minutes, the material is discharged. The manganese sulfate after high-temperature filtration is sent to a dryer for drying and then packaged into ton bags for sale. The crystallization mother liquor is returned to the process of preparing 20-30% sulfuric acid stripping solution.

2. The method for producing magnesium sulfate and manganese sulfate according to claim 1, characterized in that: The magnesium sulfite is mixed with a solution of manganese oxide ore or water and stirred evenly, and then sulfuric acid is added dropwise for reaction. The sulfur dioxide generated during the reaction is absorbed by manganese oxide ore powder and converted into manganese sulfate. The filtered liquid after the reaction of magnesium sulfite, manganese oxide ore and sulfuric acid is separated into magnesium sulfate and manganese sulfate by an extraction method. In the reaction process, the tail gas is absorbed by manganese dioxide ore powder slurry, and the manganese dioxide slurry after absorption saturation is sent to the reaction tank to recover manganese sulfate. The magnesium sulfate concentration of the leached solution can be cooled to obtain clean magnesium sulfate heptahydrate.

3. The method for producing magnesium sulfate and manganese sulfate according to claim 1, characterized in that: In the magnesium sulfate crystallization process, cooling crystallization is used to obtain magnesium sulfate heptahydrate, or concentrated sulfuric acid is added to obtain magnesium sulfate monohydrate, and then magnesium carbonate, magnesium oxide, magnesium hydroxide or other magnesium compounds are used to neutralize the residual acid to produce magnesium sulfate monohydrate.

4. The method for producing magnesium sulfate and manganese sulfate according to claim 1, characterized in that: The extraction method of the filtrate after the reaction of magnesium sulfite and manganese oxide ore powder with sulfuric acid is: the extractant for extracting manganese is magnesium sulfite or magnesium oxide as a saponifying agent or used to extract manganese at a certain pH value to separate manganese and magnesium, and the extractant for extracting magnesium is manganese carbonate or manganese monoxide as a saponifying agent or used to extract magnesium at a certain pH value to separate manganese and magnesium.

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