JP2017178749A - Method for producing manganese sulfate aqueous solution and method for producing manganese oxide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide manganese oxide having an extremely low impurity content by an industrially advantageous method with high productivity and at a low running cost.SOLUTION: A method for producing a manganese sulfate aqueous solution uses natural manganese ore and includes at least the steps 1 to 6 as given below: a step 1 of reducing natural manganese ore; a step 2 of bringing at least a part of the reduced substance of manganese ore produced in the step 1 into contact with water or an aqueous solution to carry out exudation treatment and thereafter performing solid-liquid separation to be separated into solid matter and a filtrate; a step 3 of adding at least a part of the solid matter produced in the step 2 to an aqueous solution containing sulfuric acid until a pH of the aqueous solution attains 0.5 to 3.0; a step 4 of adjusting a pH of at least a part of the filtrate including the dissolved potassium produced in the step 2 to 0.5 to 3.0 and then adding an iron compound to the filtrate to produce a jarosite crystal or a jarosite composition; a step 5 of adding the jarosite crystal or the jarosite composition produced in the step 4 to the solution or the slurry produced in the step 3 and carrying out a treatment; and a step 6 of performing solid-liquid separation of the slurry produced in the step 5 to be separated into solid matter and a manganese sulfate aqueous solution.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing an aqueous manganese sulfate solution having a low environmental load, and a method for producing a manganese oxide using the aqueous manganese sulfate solution. Specifically, the present invention relates to a method for producing a manganese oxide having an extremely small impurity content using a manganese ore containing impurities as a raw material.

  Manganese oxide is a useful compound that is widely used in dry battery materials, secondary battery materials, ferrite raw materials, oxidizing agents, catalysts, thermistors, air cleaning materials, and the like.

  In recent years, high purity of manganese oxide has been demanded in the electronic industry such as high-performance dry batteries and lithium ion secondary batteries. High-purity manganese oxides contain impurities in the raw manganese ore, ie, potassium, sodium, iron, molybdenum, arsenic, nickel, cobalt, copper, chromium, magnesium, aluminum, barium, zinc, lead, calcium, silicon, etc. It is obtained by removing.

  Conventionally, high-purity manganese oxide is obtained by reducing and roasting manganese ore produced in nature to obtain manganese-reduced ore, which is dissolved and treated in sulfuric acid aqueous solution. The resulting manganese sulfate aqueous solution is electrolyzed and chemically synthesized. It is manufactured by depositing manganese oxide crystals by applying the method. Since the natural manganese ore contains impurities such as heavy metals such as potassium, nickel, and cobalt, it is necessary to remove the impurities during the process of manufacturing the aqueous manganese sulfate solution. Potassium can be removed by (a) the jarosite method, (b) the water leaching method, or (c) a combination of the water leaching method and the jarosite method, which are described later. After precipitation as a product, it can be removed by solid-liquid separation. Here, about the potassium removal method of said (a), (b), and (c), there existed the subject as follows and it was not industrially satisfactory.

(A) Jarosite method KFe _3, which is a double salt of iron, sulfate and hydroxide, is prepared by dissolving manganese-reduced ore containing potassium in an aqueous sulfuric acid solution and then adjusting the pH by adding iron or iron salt. A method of precipitating as (SO ₄ ) ₂ (OH) ₆ (hereinafter referred to as jarosite) and removing potassium as jarosite by solid-liquid separation is disclosed (for example, Patent Document 1).

  However, in this method, almost all of the potassium contained in the manganese reduced ore is dissolved in the sulfuric acid aqueous solution. However, a large amount of iron is required to reduce the dissolved potassium to a concentration suitable for the production of manganese oxide. There was a problem that would increase. Moreover, since the jarosite formation reaction is not so fast, a large reaction tank capable of securing a sufficient staying time for treating a large amount of potassium is required, and there is a problem that the amount of capital investment is high. Furthermore, after the formation of jarosite, iron added excessively is precipitated as a hydroxide with a neutralizing agent and then separated into solid and liquid together with the jarosite and discarded. There was a problem that is large.

(B) Water leaching method In the water leaching method, manganese ore containing potassium is reduced to roasted and then contacted with water or an alkaline aqueous solution, and potassium is dissolved in water or an alkaline aqueous solution to be contained in the manganese reduced ore. This is a method of reducing potassium to a target concentration (for example, Patent Documents 2 to 3). Further, as an improved method, a method of facilitating water leaching of potassium by reducing the reduction roasting temperature to 400 ° C. to 790 ° C. is disclosed (for example, Patent Document 4).

  However, after treating at the normal reducing roasting temperature (800 to 1000 ° C.), the method of contacting with water or an alkaline aqueous solution requires a large amount of alkaline agent because the potassium leaching rate is slow, In the method using water, it is necessary to increase the temperature. Therefore, the energy for heating is enormous, and moreover, when the leaching temperature is 100 ° C. or higher, an expensive high pressure resistant equipment may be required. It was not an industrially superior method.

  In the improved method in which the reduction roasting temperature is 400 ° C. to 790 ° C., the leaching efficiency of potassium is improved and industrially excellent. However, because the reduction roasting temperature is low, the reduction rate becomes slow and the manganese ore Since the reduction roasting process may take a long time, there may be a demand for further improvement in productivity.

(C) A combination of the jarosite method and the water leaching method The above (a) jarosite method and (b) a method of removing potassium by combining the water leaching method, specifically, after reducing roasting treatment of manganese ore This is a method of leaching potassium in water and removing potassium that could not be removed as jarosite in an aqueous sulfuric acid solution.

  However, in this method, since the potassium concentration in the manganese-reduced ore is reduced by the water leaching method, it has been found that the jarosite production rate is significantly reduced as compared with the general jarosite method. For this reason, in order to promote the jarosite formation reaction, it is necessary to add a large excess of iron, the drug cost is increased, and the amount of waste is increased.

Japanese Patent Publication No. 60-166231 Japanese Patent Laid-Open No. 4-74720 Japanese Examined Patent Publication No. 47-2424 Japanese Patent No. 4730488

  An object of the present invention is a method of producing a high-purity manganese sulfate aqueous solution and a method for producing manganese oxide using the manganese sulfate aqueous solution, which is a problem when removing potassium from manganese ore as a raw material. To provide a method for producing manganese oxide that solves the above-mentioned problems, such as high costs such as capital investment, reduction of production efficiency, and environmental burden caused by waste generated as a result of removal There is. That is, an object of the present invention is to provide an industrially advantageous method excellent in economical efficiency, productivity, and environmental load reduction, for producing a manganese oxide having a very small impurity content from manganese ore containing impurities.

  As a result of intensive studies, the inventors applied water leaching to manganese-reduced ore to obtain an aqueous solution containing potassium and a treated product of manganese-reduced ore, and using the aqueous solution containing potassium as a raw material for jarosite crystals By manufacturing and adding the jarosite crystals to the reduced ore treated product and iron sulfuric acid aqueous solution or slurry, it is found that the above problems can be solved, productivity can be improved, and environmental load can be reduced. It came to be completed. That is, this invention is a manufacturing method of the manganese sulfate aqueous solution characterized by using the natural manganese ore as a raw material and including the following processes 1-6 at least.

  Step 1: A step of reducing natural manganese ore.

  Step 2: A step of leaching the manganese-reduced ore obtained in Step 1 by bringing it into contact with water or an aqueous solution, followed by solid-liquid separation into a solid and a filtrate.

  Step 3: A step of adding at least a part of the solid content obtained in Step 2 to an aqueous solution containing sulfuric acid until the pH of the aqueous solution becomes 0.5 to 3.0.

  Step 4: After adjusting the pH of at least a part of the filtrate containing dissolved potassium obtained in Step 2 to 0.5 to 3.0, an iron compound is added thereto to form jarosite crystals or jarosite Obtaining a composition;

  Step 5: A step of adding the jarosite crystal or jarosite composition obtained in Step 4 to the solution or slurry obtained in Step 3 for treatment.

  Process 6: The process of carrying out solid-liquid separation of the slurry obtained at the process 5, and isolate | separating into solid content and manganese sulfate aqueous solution.

  Hereinafter, the present invention will be described in detail.

  The method for producing an aqueous manganese sulfate solution of the present invention uses natural manganese ore as a raw material and includes at least the following steps 1 to 6.

  The feature of the method for producing an aqueous manganese sulfate solution of the present invention is that potassium in the reduced ore is removed by leaching using water or an aqueous solution in step 2, and jarosite crystals or jarosite is obtained in step 4 using the eluted potassium as a raw material. Producing the composition and adding the produced jarosite crystals or jarosite composition as seed crystals in step 5; In this way, it is possible to drastically reduce the amount of iron added to jarosite generation without purchasing expensive potassium raw materials, high productivity, low running costs, and industrially advantageous manganese sulfate. It becomes possible to provide the manufacturing method of aqueous solution and manganese oxide.

<Step 1>
Step 1 is a step of reducing natural manganese ore.

  If the kind of natural manganese ore used for this invention is naturally produced, it will not specifically limit. Among these, manganese oxide ores such as soft manganese ore and hard manganese ore have a large amount of production, are easily available, have a high manganese content, and can be suitably used.

  Even if the manganese ore is a lump as it is mined, the particle size may be reduced by pulverization. Since the surface area of the ore can be increased and the reduction rate and the leaching rate of potassium water or an aqueous alkaline solution can be improved, it is preferable to perform pulverization. In order to reliably improve the reduction rate and the leaching rate, the more preferable particle size of the ore after pulverization is 500 μm or less, and more preferably 300 μm or less.

  The reduction treatment of manganese ore may be any method as long as tetravalent manganese in manganese ore can be reduced to divalent, and may be a dry method or a wet method. . In order to maintain the reduction rate and improve productivity by using moderate heat energy, a dry method, preferably a method of contact treatment with a reducing gas at a temperature of 400 ° C. to 1200 ° C. is used, and a more preferable temperature. Is 600 ° C. to 1200 ° C., and a more preferable temperature is 800 ° C. to 1100 ° C.

  The reducing gas may be anything as long as it can reduce manganese ore. Specifically, although not particularly limited, hydrogen gas, carbon monoxide gas, methane gas, or the like can be used. This reducing gas may be supplied as a gas into the reducing device, or a raw material of gas may be input to generate reducing gas simultaneously with the reduction process. The reducing device to be used is not particularly limited as long as it can reduce manganese ore.

<Process 2>
Step 2 is a step in which at least a part of the manganese reduced ore obtained in Step 1 is brought into contact with water or an aqueous solution and subjected to leaching treatment, and then solid-liquid separated into a solid content and a filtrate.

  The water or aqueous solution used in this step is not particularly limited as long as it can dissolve potassium contained in the manganese reduced ore. Although it does not specifically limit as a specific example of water, Pure water, ultrapure water, ion-exchange water, tap water, river water, etc. can be illustrated. The aqueous solution is a solution in which various solutes are dissolved using water as a solvent, and any solute may be used, which may be inorganic or organic. Preferably, an alkali agent that can promote potassium leaching, more preferably an alkali metal hydroxide, carbonate, bicarbonate, more preferably sodium hydroxide or potassium hydroxide that is inexpensive and has a high leaching effect. is there. You may use at least one part among the solutions obtained at the process 2 as an aqueous solution which contacts a manganese reduced ore again. By doing so, it is possible to reduce the amount of water used, which is preferable because it is a better method both environmentally and economically. Furthermore, by performing such treatment, the potassium concentration in the solution can be increased, and it becomes easy to use as a raw material for preparing jarosite in step 4.

  The ratio of manganese reduced ore to water or aqueous solution is not particularly limited, but can be sufficiently brought into contact with water or aqueous solution, efficiently leaching potassium, and more efficiently equipment for treating manganese reduced ore. Therefore, the weight ratio of (manganese reduced ore) :( water or aqueous solution) is preferably 10: 1 to 1:20, more preferably 5: 1 to 1:15, and even more preferably 2: 1 to 1: 10.

  The treatment temperature is not particularly limited, but the preferable range of the treatment temperature is 30 ° C. to 99 ° C. because the potassium leaching rate can be increased to sufficiently remove potassium and the capital investment can be kept low. Yes, more preferably 50 ° C to 95 ° C, still more preferably 60 ° C to 95 ° C.

  The treatment time is not particularly limited, but is preferably 5 minutes to 10 hours, more preferably 30 minutes to 8 hours, and even more preferably 2 hours to 6 hours in order to sufficiently remove potassium and improve productivity. It's time.

  After the solid-liquid separation, the obtained solid content may be subjected to the process 3 as it is, or may be washed with water before the process 3 is performed. Preferably, the aqueous solution containing attached potassium can be removed by washing. The type of water used for washing is not particularly limited, but pure water, ion exchange water, tap water, river water, and the like are preferable from the viewpoint of price and availability.

<Step 3>
Step 3 is a step of adding at least a part of the solid content obtained in Step 2 to an aqueous solution containing sulfuric acid until the pH of the aqueous solution becomes 0.5 to 3.0.

  The aqueous solution containing sulfuric acid used in this step is not particularly limited as long as it is an aqueous solution containing sulfuric acid, and specific examples thereof include concentrated sulfuric acid, dilute sulfuric acid, sulfuric acid aqueous solution containing manganese sulfate, and the like. The treatment temperature is not particularly limited, but is preferably 50 ° C. to 95 ° C., more preferably 60 ° C. to 95 ° C., and even more preferably 70 ° C. to 95 ° C. because the dissolution rate can be maintained quickly and the heat energy can be reduced.

  Moreover, the pH at the time of completion of addition of at least a part of the solid content obtained in Step 2 is preferably 1.0 to 2.5, more preferably 1 in terms of a high rate of formation of jarosite crystals in Step 5. .2 to 2.0.

  In this step, it is necessary to add at least a part of the solid content obtained in Step 2 to the aqueous solution containing sulfuric acid until the pH of the aqueous solution becomes 0.5 to 3.0. If the pH is less than 0.5, jarosite crystals are not formed in step 5, and potassium cannot be removed. If it exceeds 3.0, the iron source is water before forming the jarosite crystals in step 5. It becomes iron oxide and potassium cannot be removed.

  By this operation, iron contained in the ore becomes an iron source, and jarosite can be generated. In addition, when there is little iron contained in an ore or when a jarosite production rate is slow, it is also possible to add an additional iron source suitably. In this case, as the iron source to be used, the same iron compound as that used in Step 4 can be exemplified.

  The amount of iron source added in this step is not particularly limited, but it is in the range of 1 to 25 times mol in terms of iron element with respect to 1 mol of dissolved potassium in terms of a high rate of formation of jarosite crystals. Preferably, the range is 2 to 20 moles, more preferably 3 to 15 moles.

<Step 4>
In step 4, the pH of at least a portion of the filtrate containing dissolved potassium obtained in step 2 is adjusted to 0.5 to 3.0, and an iron compound is added thereto to add jarosite crystals or jarosite crystals. It is a process of obtaining a site composition.

Jarosite is a double salt of potassium, iron, sulfate radical and hydroxide represented by the composition formula KFe ₃ (SO ₄ ) ₂ (OH) _{6 as} described above, and that it is jarosite crystal is powder X-ray diffraction It can be confirmed by methods, composition analysis, etc. The jarosite composition represents a composition containing the jarosite crystal, and the jarosite composition preferably has a high jarosite crystal content. The preferred jarosite crystal content in the jarosite composition is 10% or more, more preferably 30% or more, and still more preferably 50% or more.

  For the production of jarosite, it is essential to use the solution (filtrate) obtained in step 2 as a potassium raw material. The pH of the solution (filtrate) obtained in step 2 is adjusted to 0.5 to 3.0, and after the iron compound is added, it is aged at a predetermined temperature and time to obtain a jarosite crystal or jarosite composition. Can be deposited. When the pH is less than 0.5, jarosite crystals cannot be generated, and when it exceeds 3.0, the iron source becomes iron hydroxide before generating the jarosite crystals. The pH needs to be a pH at which jarosite is easily generated. Preferably it is 1.0-2.5, More preferably, it is 1.2-2.0. Further, the aging temperature and the aging time are not particularly limited as long as the temperature and time are sufficient for generating jarosite. Preferably, the temperature is 50 ° C or higher for 5 minutes to 10 hours, more preferably 60 ° C to 95 ° C, 30 minutes to 8 hours, and further preferably 70 ° C to 95 ° C, 1 hour to 5 hours.

  In order to adjust the pH of the solution (filtrate) obtained in step 2 to 0.5 to 3.0, an aqueous solution containing sulfuric acid is used. The aqueous solution containing sulfuric acid used in this step is not particularly limited as long as it is an aqueous solution containing sulfuric acid, and specific examples thereof include concentrated sulfuric acid, dilute sulfuric acid, sulfuric acid aqueous solution containing manganese sulfate, and the like.

The iron compound serving as the iron source of jarosite is not particularly limited as long as it is metallic iron, iron salt, and / or iron complex compound capable of generating jarosite. Specific examples include, but are not limited to, metallic iron, Fe (II) compound, Fe (III) compound, and the like. In the case of metallic iron, it is not particularly limited as long as it dissolves in an acid to produce Fe (II) and / or Fe (III). For example, it may be powdery, granular, or plate-like. . In the case of Fe (II), there is no particular limitation as long as it is a compound of Fe (II). Is preferred. The Fe (II) compound is not particularly limited, for _{example, FeSO 4, Fe (NO 3} ) can be exemplified 2, FeCl _2, and the like. The oxidizing agent used in combination is not particularly limited as long as it can oxidize Fe (II) to Fe (III), and examples thereof include air, hydrogen peroxide, ozone, manganese dioxide, and hypochlorite. In the case of Fe (III), there is no particular limitation as long as it is a compound of Fe (III). _{Specifically, Fe 2 (SO 4) 3} , Fe (NO 3) 3, can be exemplified FeCl ₃ and the like. These iron sources more preferably contain at least metallic iron, FeSO ₄ , or Fe ₂ (SO ₄ ) ₃ from the viewpoint that the generation and mixing of impurities can be reduced as much as possible.

  The amount of iron source added in this step is not particularly limited, but it is in the range of 1 to 25 times mol in terms of iron element with respect to 1 mol of dissolved potassium in terms of a high rate of formation of jarosite crystals. Preferably, the range is 2 to 20 times mol, and more preferably 3 to 15 times mol.

  In addition, the jarosite crystal or jarosite composition obtained by the above method may be added as a slurry to the solution or slurry obtained in step 3 in the step 5, or may be added after concentration. . Furthermore, a solid obtained by solid-liquid separation may be added. When adding solids obtained by solid-liquid separation, jarosite crystals or jarosite composition may be washed. If potassium remains in the adhering liquid, washing reduces the potassium concentration. This is preferable because it is possible. Further, the washed jarosite crystals or the jarosite composition may be added as a slurry again.

<Step 5>
Step 5 is a step of adding the jarosite crystal or jarosite composition obtained in Step 4 to the solution or slurry obtained in Step 3 for treatment.

  By adding a jarosite crystal or a jarosite composition, jarosite formation in this step is promoted, and potassium can be removed with a smaller iron addition amount.

  The pH of the solution or slurry in step 5 is not particularly limited as long as jarosite crystals are generated. However, in order to improve the rate of jarosite crystal generation and sufficiently remove potassium, the preferable pH is 0. 0.5 to 3.0, more preferably 1.0 to 2.5, and still more preferably 1.2 to 2.0.

  The temperature is not particularly limited as long as the dissolved potassium can be reduced to the target concentration. However, in order to increase the jarosite generation rate, to sufficiently remove potassium, and to further reduce the energy cost, preferably from 50 ° C. It is 95 degreeC, More preferably, it is 60 degreeC-95 degreeC, More preferably, it is 70 degreeC-95 degreeC.

  The amount of dissolved iron in the solution or slurry when the jarosite crystal or jarosite composition is added is not particularly limited as long as the dissolved potassium can be reduced to the target concentration, but the amount of jarosite generated is increased to precipitate the dissolved potassium. In order to further reduce the running cost and the environmental aspect, the molar ratio of dissolved iron to dissolved potassium is 1: 1 to 25: 1 (1 mol of dissolved iron is 1 to 25 mol per mol of dissolved potassium). Double mole), more preferably 2: 1 to 20: 1 (2 to 20 moles of dissolved iron relative to 1 mole of dissolved potassium), more preferably 3: 1 to 15: 1 (1 mole of dissolved potassium). On the other hand, the dissolved iron is 3 to 15 times mol).

  The iron source of jarosite is as described in the description of step 4, but the iron content in manganese ore can be used, and the same iron compound as shown in step 4 is additionally added. Can also be used.

  The amount of jarosite crystal or jarosite composition added is not particularly limited as long as the jarosite production rate can be increased. However, in order to promote jarosite production and prevent an increase in waste, a solution or slurry 1 is preferable. It is 0.05g-22g per liter, More preferably, it is 0.08g-10g, More preferably, it is 0.1g-5g.

  After adding the jarosite crystal or jarosite composition, it is preferable to perform an aging treatment. By aging treatment, more jarosite is generated and it becomes easy to remove potassium. The aging time is preferably 5 minutes to 10 hours, more preferably 1 hour to 7 hours, and even more preferably 2 hours in order to sufficiently generate jarosite, to sufficiently remove potassium, and to improve productivity. ~ 5 hours.

<Step 6>
Step 6 is a step in which the slurry obtained in Step 5 is subjected to solid-liquid separation and separated into a solid content and an aqueous manganese sulfate solution.

  The solid content to be separated refers to jarosite crystals, jarosite composition and other solid contents.

  Although it does not specifically limit about pH, It is preferable to adjust the pH of the slurry obtained by the process of the process 5 or the pH of the manganese sulfate aqueous solution obtained at the process 6 to 3.0-7.0. This is because, by setting the pH to 3.0 to 7.0, excess iron that has not been consumed for jarosite formation can be precipitated and removed as iron hydroxide. A more preferred pH is 3.5 to 6.5, still more preferably 4.0 to 6.0. The neutralizing agent used for the pH adjustment is not particularly limited as long as the pH can be adjusted. Preferably, the solid content obtained in step 2 is used. This is because potassium is removed from the solid content in Step 2, and the potassium concentration can be lowered as compared with the case of using manganese ores conventionally used. Moreover, it is cheaper and less likely to be contaminated with impurities as compared with the case where other neutralizing agents are used.

<Manufacturing process of manganese oxide>
The manganese oxide production method of the present invention deposits manganese oxide from the manganese sulfate aqueous solution obtained in step 6. The method for depositing the manganese oxide is not particularly limited, but an electrolytic method, a chemical synthesis method, or the like can be used. Specifically, the electrolytic method is a method in which manganese oxide is deposited on the anode by immersing the anode and the cathode in the solution obtained in step 6 and flowing electricity, and a known technique can be applied. The chemical synthesis method is a method for obtaining manganese oxide by adding an oxidizing agent to the solution obtained in step 6, precipitating manganese oxide crystals and solid-liquid separation, and applying a known technique. it can.

<Common to all processes>
The method for producing an aqueous manganese sulfate solution of the present invention may be carried out batchwise in each step, or may be carried out continuously or semi-batchwise. In addition to the described steps, a step such as a step of purifying various impurities can be arbitrarily added.

  The method for producing an aqueous manganese sulfate solution of the present invention may include a step of removing heavy metal elements. The method for removing the heavy metal element is not particularly limited, and examples thereof include a method for filtering and removing heavy metals as hydroxide, oxide, sulfide and the like.

  In the present invention, the solid-liquid separation may be anything as long as it can separate the solid content and solution after the treatment. For example, centrifugal separation, pressure filtration, vacuum filtration, sedimentation separation, etc. can be applied.

  In the present invention, the solution represents a liquid phase using water as a solvent and having no solid content. Moreover, a slurry represents the liquid phase and solid content mixture which used water as the solvent.

  In the present invention, at least a part represents 5% or more of the whole.

  By adopting the method for producing an aqueous manganese sulfate solution and the method for producing a manganese oxide of the present invention, the manganese oxide is an industrially advantageous method with high productivity, low running cost, and extremely low impurity content. Can be manufactured, and is extremely useful in industry.

2 is a powder X-ray diffraction pattern of the jarosite composition of Example 1. FIG.

  Next, although an Example demonstrates this invention, this invention is not limited to these Examples.

Example 1
Manganese dioxide ore containing 51.6% by weight manganese, 0.63% by weight potassium and 2.70% by weight iron is pulverized to a particle size of 300 μm or less, and then subjected to reduction roasting with carbon monoxide gas using a rotary kiln. (Step 1). The reduction temperature was 900 ° C., and the average residence time was 2 hours. 252 g of this reduced ore was placed in a stirring tank and leached with 585 g of warm water at 90 ° C. for 5 hours, followed by filtration and washing (step 2).

400 g of this filtrate was put into a stirring tank, adjusted with dilute sulfuric acid so that the pH was 1.6, and then 28 g of ferrous sulfate (FeSO ₄ ) .7 hydrate was added. After adding 6.6 g of manganese dioxide ore as an oxidant, it was treated at 90 ° C. for 4 hours, filtered and washed to obtain 16 g of a jarosite composition (step 4). The powder X-ray diffraction pattern of the jarosite composition is shown in FIG.

In step 2, after the treatment with warm water, 12 g of solid content (manganese ore treated product) obtained by filtration and washing was returned to 90 ° C. Return solution (sulfuric acid aqueous solution containing manganese sulfate after electrolytic oxidation: potassium Dissolved in 450 g (concentration 20 mg / L), 0.85 g of ferrous sulfate (FeSO ₄ ) heptahydrate was added to obtain a slurry (step 3). The pH at this time was 1.6.

  To the slurry obtained in Step 3, 0.86 g of the jarosite composition obtained in Step 4 and 0.44 g of manganese dioxide ore as an oxidizing agent were added, and the resulting mixture was stirred at a temperature of 90 ° C. ( Step 5). As a result, the dissolved potassium concentration became 20 mg / L or less after 2 hours. When the jarosite composition was added, the dissolved potassium concentration was 45 mg / L, and the dissolved iron concentration was 600 mg / L.

  To the slurry having a dissolved potassium concentration of 20 mg / L or less, a cake (manganese ore treated product) obtained by filtration after the treatment with the warm water was added so as to have a pH of 5.0. Thereafter, filtration and washing were performed (step 6). The dissolved potassium concentration at this time was 20 mg / L or less. The manganese sulfate aqueous solution thus purified is electrolytically oxidized to deposit manganese dioxide on the anode, followed by peeling, grinding, washing, and drying, so that 58.5% by weight manganese, 0.03% by weight potassium, 0% iron An electrolytic manganese dioxide containing 0.02% by weight was obtained.

Example 2
Electrolytic manganese dioxide was obtained in the same manner as in Example 1 except that 1.7 g of ferrous sulfate (FeSO ₄ ) .7 hydrate, 0.29 g of jarosite composition, and 0.66 g of manganese dioxide ore were added. It was. After adding ferrous sulfate (FeSO ₄ ) heptahydrate, jarosite composition, and manganese dioxide ore, the dissolved potassium concentration became 20 mg / L or less in 2 hours. When the jarosite composition was added, the dissolved potassium concentration was 40 mg / L, and the dissolved iron concentration was 1030 mg / L.

Example 3
Electrolytic manganese dioxide was prepared in the same manner as in Example 1 except that ferrous sulfate (FeSO ₄ ) heptahydrate was not added, 7.3 g of jarosite composition and 0.18 g of manganese dioxide ore were added. Obtained. After adding the jarosite composition and manganese dioxide ore, the dissolved potassium concentration became 20 mg / L or less in 2 hours. When the jarosite composition was added, the dissolved potassium concentration was 43 mg / L, and the dissolved iron concentration was 280 mg / L.

Comparative Example 1
Electrolytic manganese dioxide was obtained in the same manner as in Example 1 except that the jarosite composition was not added. After adding ferrous sulfate (FeSO ₄ ) .7 hydrate and manganese dioxide ore, the dissolved potassium concentration became 20 mg / L or less in 7 hours. The dissolved potassium concentration after addition of ferrous sulfate heptahydrate was 44 mg / L, and the dissolved iron concentration was 610 mg / L.

Comparative Example 2
8.4 g of reduced ore was dissolved in 450 g of a return solution (sulfuric acid aqueous solution containing manganese sulfate after electrolytic oxidation: potassium concentration 20 mg / L) without treatment with warm water (the pH at this time was 1.6). In the same manner as in Example 1, except that 3.4 g of ferrous sulfate (FeSO ₄ ) heptahydrate and 1.2 g of manganese dioxide ore were added and no jarosite composition was added. Electrolytic manganese dioxide was obtained. After adding ferrous sulfate (FeSO ₄ ) .7 hydrate and manganese dioxide ore, the dissolved potassium concentration became 20 mg / L or less in 2 hours. The dissolved potassium concentration after addition of ferrous sulfate heptahydrate was 161 mg / L, and dissolved iron was 1850 mg / L.

Comparative Example 3
Electrolytic manganese dioxide was obtained in the same manner as in Comparative Example 2, except that 1.7 g of ferrous sulfate (FeSO ₄ ) .7 hydrate and 0.66 g of manganese dioxide ore were added. After adding ferrous sulfate (FeSO ₄ ) heptahydrate and manganese dioxide ore, the dissolved potassium concentration became 20 mg / L or less in 6 hours. The dissolved potassium concentration after addition of ferrous sulfate heptahydrate was 160 mg / L, and dissolved iron was 1040 mg / L.

  Table 1 shows the main conditions and results of Examples 1 to 3 and Comparative Examples 1 to 3.

Examples 4-10
2 g to 15 g of manganese reduced ore obtained by the same method as in Example 1 was put in a Teflon container, shaken with 15 g to 18 g of water at 30 ° C. to 90 ° C. for 1 hour to 8 hours, and then filtered and washed. went. Table 2 shows the conditions and the dissolution rate of potassium. It was confirmed that potassium could be eluted under the conditions of Examples 4-10.

  By adopting the method for producing an aqueous manganese sulfate solution and the method for producing a manganese oxide of the present invention, the manganese oxide is an industrially advantageous method with high productivity, low running cost, and extremely low impurity content. Can be manufactured, and is extremely useful in industry.

  Manganese oxides produced by the production method of the present invention can be widely used for dry battery materials, secondary battery materials, ferrite raw materials, oxidizing agents, catalysts, thermistors, air cleaning materials, and the like.

Claims (17)

A method for producing an aqueous manganese sulfate solution comprising natural manganese ore as a raw material and comprising at least the following steps 1 to 6.
Step 1: A step of reducing natural manganese ore.
Step 2: A step of leaching the manganese-reduced ore obtained in Step 1 by bringing it into contact with water or an aqueous solution, followed by solid-liquid separation into a solid and a filtrate.
Step 3: A step of adding at least a part of the solid content obtained in Step 2 to an aqueous solution containing sulfuric acid until the pH of the aqueous solution becomes 0.5 to 3.0.
Step 4: After adjusting the pH of at least a part of the filtrate containing dissolved potassium obtained in Step 2 to 0.5 to 3.0, an iron compound is added thereto to form jarosite crystals or jarosite Obtaining a composition;
Step 5: A step of adding the jarosite crystal or jarosite composition obtained in Step 4 to the solution or slurry obtained in Step 3 for treatment.
Process 6: The process of carrying out solid-liquid separation of the slurry obtained at the process 5, and isolate | separating into solid content and manganese sulfate aqueous solution. 2. The method for producing an aqueous manganese sulfate solution according to claim 1, wherein the method of reducing the natural manganese ore in Step 1 is a method of contacting with a reducing gas at a temperature of 400 ° C. to 1200 ° C. 3. The weight ratio of (manganese reduced ore) :( water or aqueous solution) in step 2 is 10: 1 to 1:20, the processing temperature in step 2 is 30 ° C. to 99 ° C., and the processing time is 5 minutes to 10 hours. The method for producing an aqueous manganese sulfate solution according to claim 1 or 2, wherein The manganese sulfate aqueous solution according to any one of claims 1 to 3, wherein at least a part of the filtrate containing dissolved potassium obtained in step 2 is used as an aqueous solution in contact with manganese reduced ore. Production method. The solid content obtained in step 2 used in step 3 is at least a portion of the solid content obtained in step 2 and an iron compound. The manufacturing method of the manganese sulfate aqueous solution in any one.
In step 4, the amount of iron compound added is 1 to 25 times mol in terms of iron element with respect to 1 mol of dissolved potassium contained in the filtrate according to step 4. 6. A method for producing an aqueous manganese sulfate solution according to any one of 5 above. The manganese sulfate aqueous solution according to any one of claims 1 to 6, wherein the iron compound used in step 3 and step 4 contains at least metallic iron, FeSO ₄ or Fe ₂ (SO ₄ ) ₃ . Production method. The method for producing an aqueous manganese sulfate solution according to claim 7, wherein an oxidizing agent is used in combination when metallic iron or FeSO ₄ is used. The pH of the slurry obtained by the treatment described in Step 5 is adjusted to 3.0 to 7.0, or the pH of the aqueous manganese sulfate solution obtained in Step 6 is adjusted to 3.0 to 7.0. The manufacturing method of the manganese sulfate aqueous solution in any one of Claims 1-8. When adjusting the pH of the slurry obtained by the treatment described in Step 5 to 3.0 to 7.0, or adjusting the pH of the aqueous manganese sulfate solution obtained in Step 6 to 3.0 to 7.0, 10. The method for producing an aqueous manganese sulfate solution according to claim 9, wherein the solid content obtained in step 2 is used as a compatibilizer. The method for producing an aqueous manganese sulfate solution according to any one of claims 1 to 10, wherein the treatment according to step 5 is performed at a liquid temperature in the range of 50C to 95C. The solution or slurry obtained by step 3 is characterized in that the molar ratio of dissolved potassium to dissolved iron is 1 to 25 times mol of dissolved iron with respect to 1 mol of dissolved potassium. The manufacturing method of the manganese sulfate aqueous solution in any one. 13. The aqueous manganese sulfate solution according to claim 1, wherein the amount of jarosite crystals added in Step 5 is 0.05 g to 22 g per liter of the solution or slurry described in Step 5. Production method. The method for producing an aqueous manganese sulfate solution according to any one of claims 1 to 13, wherein the aging treatment is performed in the range of 5 minutes to 10 hours after adding the jarosite crystals in step 5. The method for producing an aqueous manganese sulfate solution according to claim 1, comprising steps 1 to 6 and further comprising a step of removing heavy metal elements. A method for producing manganese oxide, comprising depositing manganese oxide from an aqueous manganese sulfate solution produced by the method for producing an aqueous manganese sulfate solution according to claim 1. The method for producing manganese oxide according to claim 16, wherein the method for precipitating manganese oxide is an electrolytic method or a chemical synthesis method using an oxidizing agent.

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