JP6219325B2 - Method for producing metal manganese - Google Patents

Description

  The present invention relates to a method for producing metal manganese (hereinafter, also referred to as metal Mn), and more particularly, to a method for producing metal manganese using a recovered manganese-containing material as a raw material to produce high-grade metal manganese by an arc melting furnace.

  Common methods for producing manganese metal include electrolysis, blast furnace, and thermite. The electrolysis method is a method in which manganese raw material (manganese source) such as manganese ore is dissolved with an acid such as sulfuric acid, and then electrolyzed to obtain metallic manganese. There is a problem that is high. The blast furnace method is a method in which manganese ore (or sintered material), which is a manganese raw material (manganese source), is charged into a blast furnace together with coke and refined, and can be manufactured at a relatively low cost. There are problems such as containing impurities, difficulty in using powdery raw materials, and inability to use raw materials containing highly volatile substances such as zinc, sodium, and potassium. The thermite method is a method of obtaining manganese metal by mixing a metal such as magnesium or aluminum with a manganese raw material (manganese source) such as manganese ore and causing a thermite reaction, and the price of the reducing agent is high. Then, there was a problem that the manufacturing cost increased and it became economically disadvantageous. Against this background, the present situation is that industrial production of manganese metal is carried out only by electrolysis.

  Currently, manganese ores such as manganese oxide ore and manganese carbonate ore are common as manganese raw materials (manganese sources), but these natural resources are limited and may be exhausted. is there. Manganese is considered an essential metal in a wide range of industries, and there is concern that the demand will exceed the reserves in the future. In particular, since ironworks consume a large amount of manganese as a raw material for steelmaking, securing a manganese source has become an extremely important problem in the steelmaking field.

  In recent years, attempts have been made to actively recover manganese from low-grade raw ores, concentrates, steelworks by-products, industrial waste, etc. due to depletion of metal resources and rising transaction prices. .

  For example, some dry batteries disposed of as industrial waste have a high manganese content. A typical manganese dry battery and alkaline manganese dry battery as primary batteries use manganese dioxide as a positive electrode material and zinc as a negative electrode material. Accordingly, if a technique for recovering manganese from these waste dry batteries and reusing it as a steelmaking raw material can be established, it is expected to contribute effectively to securing a manganese source. Moreover, a huge amount of dry cells are produced, consumed and discarded in Japan.

  However, at present, a part of zinc or a part of iron or carbon is recovered by an arc melting furnace manufacturer from a manganese or alkaline manganese battery discarded after the end of discharge. However, it cannot be said that resource recycling is being carried out sufficiently. At present, many resources are still used without being recycled and used as landfill for waste disposal.

  Recently, various techniques for recovering not only zinc, iron, and carbon but also manganese from waste dry batteries have been proposed.

  For example, Patent Document 1 discloses a process of selecting manganese batteries and alkaline manganese batteries from waste dry batteries, a process of obtaining powder particles by crushing and sieving, and dissolving the obtained powder particles with dilute hydrochloric acid or dilute sulfuric acid. A method of recovering a manganese dioxide and carbon-containing mixture is described having a process step. According to the technique described in Patent Document 1, manganese dioxide and a carbon component can be easily and simultaneously recovered without causing a large loss and can be used as a starting material for producing ferromanganese.

  Patent Document 2 describes a method for separating and recovering manganese dioxide and zinc chloride from a waste dry battery. The technique described in Patent Document 2 obtains a material containing a large amount of manganese and zinc from a waste dry battery, and after washing it with water if necessary, dissolves it in hydrochloric acid and heats the solution after removing impure components with a clean solution. Concentrate, add perchloric acid to the concentrate and heat to obtain a solid mixture of manganese dioxide and zinc chloride. Dissolve the solid mixture in water and filter. Separately collect manganese dioxide and zinc chloride from the waste dry battery. It is a method to do. In the technique described in Patent Document 2, the obtained zinc chloride is dissolved in an organic solvent to remove insoluble alkali metal salts that have been mixed therein, and the zinc chloride is purified. In addition, the recovered manganese dioxide and zinc chloride are said to have a purity that can be used again for dry cell production.

  Patent Document 3 describes a metal recovery method. The technique described in Patent Document 3 uses iron-reducing bacteria to act on a group consisting of a metal oxide and a metal hydroxide, reduces trivalent iron to divalent iron, and uses the obtained divalent iron. Leaching a metal such as cobalt, nickel, manganese, etc., contained in the group consisting of metal oxide and metal hydroxide, producing a leachate and residue, separating the obtained leachate and residue, and removing the desired metal This is a metal recovery method for recovery. The group consisting of metal oxides and metal hydroxides includes wastes such as deep-sea bottom mineral resources, metal-containing oxide ores (land minerals), and metal-containing incineration residues. According to the technique described in Patent Document 3, low-grade metals contained in metal oxides and metal hydroxides can be recovered with high speed and high efficiency. It is said that metals such as cobalt, nickel, manganese, etc. contained in the leachate can be recovered using ordinary methods.

  Patent Document 4 describes a method for producing metallic manganese. In the technique described in Patent Document 4, a manganese oxide-containing substance is charged into a heating furnace together with a reducing agent, and the furnace is heated until the furnace temperature reaches 1200 ° C. or higher to reduce manganese oxide, and then 700 ° C. This is a method for producing manganese metal which is cooled to the following and discharged outside the furnace. In the technique described in Patent Document 4, a waste battery, manganese ore, or the like can be used as the manganese oxide-containing substance, and a carbon-based reducing agent such as coal, coke, or graphite is used as the reducing agent.

JP 2007-12527 A JP-A-11-191439 JP 2007-113116 A JP 2011-94207 A

  However, in the Mn-containing materials recovered by the respective techniques described in Patent Documents 1 to 3, the contained Mn is considered to be an oxide or a hydroxide, and can be used, for example, as an ironmaking raw material. There is a problem that further reduction of Mn is required to reach the state. Further, the technique described in Patent Document 3 has a problem that the medium added to the microorganism and the agent added as a complexing agent are expensive. Further, the metal Mn produced by the technique described in Patent Document 4 often has a problem that the carbon used as the reducing agent remains and the carbon content increases, and the quality as the metal Mn is lowered. .

  The present invention solves such problems of the prior art, and can produce metal manganese that can be used as an iron-making raw material, and high-quality metal manganese comparable to electrolytic metal manganese at low cost and in a simple manner. The purpose is to provide.

  In order to achieve the above-described object, the present inventors diligently studied a method for improving the quality of metallic manganese. As a result, the purity of the manganese-containing material (manganese oxide) that is the raw material is increased, and together with the reducing agent and flux, it is charged into an arc melting furnace, energized and heated, and the manganese-containing material (manganese oxide) ) Is reduced, it is conceivable that contamination with impurities can be suppressed and high-quality metal manganese can be obtained. In particular, when Al was used as the reducing agent, the inventors realized that aluminum thermite reaction heat can be used and the input power can be reduced. Furthermore, it has been found that high-quality metallic manganese can be easily produced by using a manganese-containing substance (manganese oxide) obtained by leaching, separating and ozone-treating manganese contained in a waste battery as a manganese source. . The manganese-containing material obtained by separating and recovering Mn from this waste dry battery is characterized by a high Mn content and a low content of Fe and P, and is effective as a raw material for high-grade metal manganese. I found out.

The present invention has been completed based on such findings and further investigations. That is, the gist of the present invention is as follows.
(1) A method for producing metal manganese by subjecting a manganese-containing substance to a reduction process to produce metal manganese, wherein the reduction process is performed by charging the manganese-containing substance, a reducing agent, and a flux into an arc melting furnace. And manufacturing the high-grade metal manganese, which is an arc melting furnace reduction process in which the manganese-containing substance is reduced by heating by energization of the arc melting furnace and / or reaction heat of a reducing agent to form metallic manganese. Method.
(2) In (1), the manganese-containing substance is a manganese-containing substance obtained by subjecting manganese contained in a waste dry battery to acid leaching treatment, subjecting the obtained acid leaching solution to ozone treatment, and separation treatment. A method for producing high-grade manganese metal, characterized by:
(3) In (2), the manganese-containing substance obtained by subjecting manganese contained in the waste dry battery to acid leaching treatment, subjecting the obtained acid leaching solution to ozone treatment, and separation treatment is converted from the waste dry battery to the manganese dry battery. And / or a sorting process for sorting out alkaline manganese batteries, a crushing / sieving process for crushing and sieving waste dry batteries sorted in the sorting process, and a crushing / sieving process. Solid-liquid separation of an acid leaching step of leaching manganese and zinc from the powder and the leachate obtained in the acid leaching step and the leaching residue by mixing the powder, an acid solution and a reducing agent First solid-liquid separation step, and ozone is allowed to act on the leachate separated in the first solid-liquid separation step to oxidize and precipitate manganese ions contained in the leachate, containing manganese-containing precipitates and zinc ions With solution A manganese-containing product obtained by sequentially performing an ozone treatment step to be obtained, and a second solid-liquid separation step for solid-liquid separation of the manganese-containing precipitate obtained in the ozone treatment step and the zinc ion-containing solution. A method for producing high-grade metal manganese, which is a precipitate.
(4) In any one of (1) to (3), in the arc melting furnace reduction step, the distance between the graphite electrode of the arc melting furnace and the charge or the molten metal is increased to avoid contact. A method for producing high-grade manganese metal, characterized in that the operation is carried out.
(5) In any one of (1) to (4), the arc melting furnace reduction step is a two-stage reduction of primary reduction and finish reduction, and the primary reduction is a treatment for reducing the oxidation degree of manganese oxide. The method for producing high-grade manganese metal, wherein the finish reduction is a treatment for producing manganese metal.
(6) The method for producing high-grade metal manganese according to any one of (1) to (5), wherein the reducing agent used in the arc melting furnace reduction step is metallic aluminum or metallic silicon.
(7) The method for producing high-grade metal manganese according to (6), wherein the metal aluminum is charged in a plurality of times.
(8) The method for producing high-grade metal manganese according to (6) or (7), wherein energization of the arc melting furnace is stopped while the reduction reaction of manganese by the metal aluminum occurs.
(9) The method for producing high-grade manganese metal according to any one of (6) to (8), wherein the amount of the metal aluminum charged is 1 to 1.5 times the theoretical reduction equivalent.
(10) The method for producing high-grade metal manganese according to any one of (1) to (9), wherein the flux used in the arc melting furnace reduction step is a substance containing CaO as a main component.
(11) The method for producing high-grade metal manganese according to any one of (1) to (10), wherein the manganese-containing substance is manganese dioxide.

  ADVANTAGE OF THE INVENTION According to this invention, the high quality metal manganese comparable to electrolytic metal manganese can be manufactured cheaply and simply, and there is a remarkable industrial effect. In addition, according to the present invention, manganese, which is a main component contained in a waste dry battery, can be recovered with a high yield, can be reused as an industrial raw material, and has an effect of effectively contributing to resource recycling.

It is explanatory drawing which shows the flow in this invention. It is explanatory drawing which shows an example of the flow of a separation and collection | recovery process of manganese from a waste dry battery. It is a redox potential (ORP) and pH phase diagram (Eh-pH diagram) of manganese in an aqueous solution. It is a graph which shows the relationship between the amount of aluminum addition as a reducing agent, the amount of aluminum in a metal, Mn yield, and the amount of S in a metal. It is explanatory drawing which shows typically the outline | summary of the arc melting furnace reduction process in an Example.

  The present invention is a method for producing metallic manganese in which a manganese-containing substance (manganese oxide) is used as a raw material, and the raw material is subjected to a reduction step to form metallic manganese. FIG. 1 shows a flow of the method of the present invention.

  The reduction process in the present invention is an arc melting furnace reduction process using an arc melting furnace. In the arc melting furnace reduction process, a reducing agent and a flux (a slagging agent) are blended into the manganese-containing material as a raw material, and charged into the arc melting furnace. And a charging material is heated with electricity through the graphite electrode of an arc melting furnace, a manganese-containing substance is reduced with a reducing agent, and a molten metal (metallic manganese) is obtained. Here, it is preferable that the arc melting furnace to be used is a furnace that can be tilted for discharging the generated molten metal and discharging molten slag.

  The raw material to be used is not particularly limited as long as it is a manganese-containing substance, but from the viewpoint of producing high-grade metal manganese, manganese dioxide (drug: commercially available product), It is preferable that a manganese-containing substance obtained by subjecting manganese contained in the waste dry battery to an acid leaching treatment, an ozone treatment to the obtained acid leaching solution, and a separation treatment, which has been partially found. This manganese-containing substance is a high-purity manganese oxide that contains very little zinc, carbon, and the like other than manganese, and is suitable as a raw material for producing high-grade metallic manganese.

  A method for recovering high-purity manganese oxide from a waste dry battery discovered by some of the present inventors is detailed in the specification of Japanese Patent Application No. 2014-87269, but an outline will be described below.

  Sorting process 1 for sorting manganese batteries and / or alkaline manganese batteries from waste batteries, crushing / sieving process 2 for crushing and sieving the waste dry batteries sorted in the sorting process to obtain a powder fluid, An acid leaching step 3 for leaching manganese and zinc from the granular material by mixing the granular material obtained in the sieving step, an acid solution, and a reducing agent, and an leaching solution and a leaching obtained in the acid leaching step A first solid-liquid separation step 4 for solid-liquid separation of the residue, and ozone is allowed to act on the leachate separated in the first solid-liquid separation step to oxidize and precipitate manganese ions contained in the leachate; An ozone treatment step 5 for obtaining a manganese-containing precipitate and a zinc ion-containing solution, and a second solid-liquid separation step 6 for solid-liquid separation of the manganese-containing precipitate and the zinc ion-containing solution obtained in the ozone treatment step. Batteries and waste batteries The manganese component contained as manganese precipitate separates the zinc component contained in the waste battery as zinc ion-containing solution. The flow of the above-described process is shown in FIG. Hereinafter, each step will be described.

Sorting process Waste dry batteries are rarely collected separately for each type, and are generally collected in a mixed form. For this reason, first, one or both of a manganese dry battery and an alkaline manganese dry battery are selected from the discarded / recovered waste dry batteries. As a sorting method, any method may be used as long as it can exclude mercury dry batteries, nickel-cadmium batteries, and the like, such as manual sorting, machine sorting using a device that sorts using shape, radiation, and the like.

Crushing / sieving step Next, the manganese dry cell and / or the alkaline manganese dry cell sorted in the sorting step are crushed. The purpose of crushing is to eliminate materials containing components other than manganese and zinc as much as possible from the constituent materials of manganese dry batteries and / or alkaline manganese dry batteries selected in the selection step.

Among the sorted waste batteries, manganese batteries are manganese dioxide (positive electrode material), carbon rod (current collector), zinc can (negative electrode material), zinc chloride or ammonium chloride (electrolyte), MnO ( In addition to OH) and Zn (OH) ₂ , packaging materials such as iron, plastic and paper are included. Among the selected waste batteries, alkaline manganese batteries are brass bars (current collectors) instead of the carbon bars (current collectors), zinc cans (negative electrode materials), zinc chloride or ammonium chloride (electrolyte). Body), zinc powder, (negative electrode material), potassium hydroxide (electrolytic solution), and Mn (OH) ₂ , ZnO, etc. generated by discharge.

When these materials are crushed, packaging materials (iron, plastic, paper, etc.), zinc cans, which are anode materials for manganese batteries, and brass rods, which are current collectors for alkaline manganese batteries, are foil-like or piece-like. It becomes a solid substance. On the other hand, manganese dioxide as positive electrode material, carbon rod as current collector of manganese dry battery, zinc powder as negative electrode material of alkaline manganese dry battery, MnO (OH), Zn (OH) ₂ , Mn (OH) generated by discharge ₂ , ZnO, etc., and various electrolytes become finer particles than the foil-like / flaky solids described above.

  Therefore, after crushing the selected waste dry battery and sieving it with a sieve with a predetermined opening, large solids such as packaging materials are removed from the selected waste dry battery, mainly containing carbon with manganese and zinc components Can be obtained.

  A crusher is usually used for crushing the sorted waste batteries. The type of the crusher is not particularly limited, and for example, a type in which the powder material and the packaging material constituting the dry battery are well separated after crushing is preferable. As such a thing, the biaxial rotation type crusher is mentioned, for example. The sieve opening used for sieving the above crushed material (sieving between a foil-like or piece-like solid and a granular material) is preferably about 1 mm or more and 20 mm or less. Further, it is more preferably about 1 mm or more and 10 mm or less, and further preferably about 1 mm or more and 5 mm or less.

As described above, through the crushing and sieving process, manganese dioxide, carbon, zinc chloride or ammonium chloride, caustic potash, and further generated by discharge are the main constituent materials of manganese dry batteries and / or alkaline manganese dry batteries. A powder body in which MnO (OH), Zn (OH) ₂ , Mn (OH) ₂ , ZnO or the like is mixed is obtained. Moreover, a trace amount of iron component is inevitably mixed in this granular material.

  In the crushing and sieving step, the zinc can, which is the negative electrode material of the manganese dry battery, is sieved as a foil-like or piece-like solid, but this zinc can is separately collected and recycled.

Acid leaching process In the acid leaching process, the powder obtained in the crushing and sieving process, the acid solution, and the reducing agent are mixed, and the powder is subjected to an acid leaching treatment. By this acid leaching treatment, manganese and zinc are leached mainly from the granular material containing manganese / zinc component and carbon, and carbon is left in the leaching residue.

  The acid used for the acid solution may be a general acid, and sulfuric acid, nitric acid, hydrochloric acid, and other acids can be used. However, in consideration of cost and ease of procurement, sulfuric acid or hydrochloric acid is used. preferable. When sulfuric acid is used, it is preferable to use dilute sulfuric acid having a sulfuric acid concentration of 1.4 to 45% by mass. More preferably, it is dilute sulfuric acid having a sulfuric acid concentration of 2 to 30%, and more preferably dilute sulfuric acid having a sulfuric acid concentration of 5 to 25%. When hydrochloric acid is used, it is preferable to use dilute hydrochloric acid having a hydrochloric acid concentration of 1 to 14% by mass. More preferred is dilute hydrochloric acid having a hydrochloric acid concentration of 2 to 8%. The mass% concentration here is a value obtained by multiplying 100 by the mass of the acid in the acid solution divided by the mass of the entire solution.

  Regardless of which acid is used, the acid concentration required for the leaching of manganese and zinc is the solid-liquid ratio, the amount of powder, the content of manganese and zinc in the powder, the manganese in the powder. It varies depending on the form of zinc. Therefore, an optimal acid concentration can be determined by conducting a preliminary experiment assuming an actual machine in advance.

  Here, in an acid leaching process, it is essential to mix a reducing agent with a granular material and an acid solution. This is because the manganese component contained in the granular material is almost completely leached. The principle of manganese dissolution (manganese leaching) with a reducing agent will be described below.

The waste dry battery selected in the selection process includes MnO (OH), Mn (OH) ₂ generated by discharge, and undischarged MnO ₂ . Of these, MnO (OH) and Mn (OH) ₂ are considered to dissolve in acid, but MnO ₂ is considered to hardly dissolve in acid. As is clear from the half-reaction equation of MnO ₂ dissolution expressed by equation (1), it is necessary to reduce Mn from tetravalent to divalent to dissolve MnO ₂ and supply electrons for reduction. This is because a reducing agent is required as a substance to be used.

MnO ₂ (solid) + 4H ⁺ + 2e- → Mn ²⁺ (dissolved) + 2H ₂ O (1)
For this reason, in the acid leaching step, a reducing agent is added in accordance with the leaching reaction with acid. As a result, the manganese components (MnO ₂ and MnO (OH), Mn (OH) ₂ ) in the granular material can be almost completely leached. In addition, about the zinc component contained in a granular material, if the density | concentration of an acid is raised regardless of the presence or absence of a reducing agent, the whole quantity will melt | dissolve (leaching).

  The type of reducing agent to be mixed with the powder and acid solution is not particularly limited, as long as it can reduce Mn from tetravalent to divalent as shown in the formula (1). Examples include hydrogen, sulfide ions such as sodium sulfide, sodium hydrogen sulfite, and sodium thiosulfate, and those containing sulfite ions and thiosulfate ions. The method of mixing the reducing agent may be a method of adding the reducing agent as a solid or liquid, or a method of aerating a reducing gas such as sulfurous acid gas. As an example, the half reaction formula of hydrogen peroxide is shown in the following formula (2).

H ₂ O ₂ → 2H ⁺ + O ₂ + 2e- (2)
In addition, it is preferable to experimentally determine the addition amount and aeration amount of a reducing agent based on the required amount (amount required for dissolution of MnO ₂ ) obtained from a theoretical formula. The ratio of MnO (OH) to MnO ₂ and Mn (OH) ₂ in the granular material is not clear, and there is a loss in the reaction, so that it is difficult to obtain the necessary amount only by theoretical calculation.

  The acid solution and reducing agent as exemplified above are mixed with the powder obtained in the crushing / sieving step, and an acid leaching treatment is performed with stirring. In addition, when performing an acid leaching process, for example, after first mixing a granular material and an acid solution, a reducing agent can be mixed. Moreover, an acid solution, a reducing agent, and a granular material may be mixed simultaneously, and after mixing an acid solution and a reducing agent, you may mix a granular material.

  From the viewpoint of improving the efficiency of the acid leaching treatment, the solid-liquid ratio (powder (g) / acid solution (L)) of the powder and acid solution in the acid leaching process is 50 g / L or more, preferably 100 g / L or more is preferable. However, if the solid-liquid ratio exceeds 800 g / L and becomes excessively high, the viscosity may increase and handling problems may occur, or the yield during the first solid-liquid separation process described later may deteriorate. is there. Therefore, the solid-liquid ratio is preferably 800 g / L or less.

  A sufficient effect can be obtained even at room temperature (around 15 to 25 ° C.) for the acid leaching treatment temperature (atmosphere temperature or acid solution temperature), but heating may be performed. If heating is performed, the reaction efficiency can be expected to be improved. However, since heating costs are also required, it is only necessary to determine whether or not the heating can be performed in comparison with the obtained effect. The treatment time for the acid leaching treatment is preferably 60 min to 12 h.

  By the above acid leaching step, a leachate in which manganese and zinc components contained in the powder are almost completely leached is obtained. Moreover, by the above-described acid leaching step, almost the entire amount of carbon contained in the granular material can be retained in the leaching residue. Therefore, by separating the leachate and leach residue obtained in the acid leaching step by solid-liquid separation, the amount of carbon mixed in the manganese recovery product finally separated and recovered can be made extremely low.

First Solid-Liquid Separation Step In the first solid-liquid separation step, the leaching solution (leaching solution containing manganese ions and zinc ions) obtained in the acid leaching step and the leaching residue (leaching residue with carbon remaining) are subjected to solid-liquid separation. Thereby, the manganese component and the zinc component contained in the granular material and the carbon contained in the granular material can be separated. The solid-liquid separation means is not particularly limited, and may be any means selected from, for example, gravity sedimentation separation, filtration, centrifugation, filter press, membrane separation and the like.

  The leachate separated in the first solid-liquid separation step is subjected to ozone treatment in the next ozone treatment step. On the other hand, since the leaching residue separated in the first solid-liquid separation step contains high concentration of carbon, it may be recovered and reused as, for example, carbonaceous fuel.

Ozone treatment step In the ozone treatment step, ozone is allowed to act on the leachate (leachate containing manganese ions and zinc ions) separated in the first solid-liquid separation step, thereby oxidizing and precipitating manganese ions contained in the leachate. A manganese-containing precipitate and a zinc ion-containing solution are obtained. That is, in the ozone treatment process, only manganese ions out of manganese ions and zinc ions contained in the leachate are oxidized to manganese oxides (manganese-containing precipitates), thereby maintaining the zinc component in a dissolved state. While making the manganese component solid.

  Specifically, ozone is diffused into the leachate separated in the first solid-liquid separation step to adjust the redox potential (ORP) of the leachate, and the pH and redox potential (ORP) of the leachate are shown in FIG. In the Eh-pH diagram shown in Fig. 4, the region is the region where only manganese is insolubilized (solidified) and precipitated as oxide (region indicated by ○). Thereby, manganese dissolved in the leachate is preferentially insolubilized to become a solid.

  The above leachate is acidic. Therefore, it is not usually necessary to adjust the pH of the leachate, and simply adjusting the oxidation-reduction potential (ORP) by simply diffusing ozone into the leachate separated in the first solid-liquid separation step, the pH and oxidation of the leachate. The reduction potential (ORP) can be adjusted to a region where only manganese is insolubilized (solidified) and precipitated as an oxide in the Eh-pH diagram. However, the pH of the leachate may be measured prior to the ozone aeration just in case. If the measured pH is higher than the desired value, a slight acid (for example, a general acid such as sulfuric acid, nitric acid, hydrochloric acid, etc.) may be added.

Examples of the Eh-pH diagram include Pourbaix, M. Atlas of electrochemical equilibria in aqueous solutions.National Association of Corrosion Engineers. (1974) 644p.
Can be used.

  In FIG. 3, the pH and oxidation-reduction potential (ORP) of the region where manganese is solidified and precipitated as an oxide (the region surrounded by ○ in FIG. 3) are approximately “pH: 0.1 to less than 2.2”, “Oxidation”. It can be seen that it is preferable that the reduction potential (ORP) is about +0.9 V or more and +1.2 V or less.

  Therefore, after confirming that the pH of the leachate is less than 2.2, ozone is diffused into the leachate to raise the oxidation-reduction potential (ORP) to +0.9 V or higher, so that only manganese is solid as an oxide. It becomes possible to materialize and separate and precipitate from other elements.

  As the amount of ozone diffused, ozone was diffused while observing the oxidation-reduction potential (ORP), and the oxidation-reduction potential (ORP) was a predetermined value (for example, the temperature of the leachate was 25 ° C., and Mn in the leachate , Zn and Fe concentrations are preferably adjusted to about +1 V or more when Mn: 0.1M, Zn: 0.1M, and Fe: 0.05M, respectively.

By such an ozone treatment process, manganese in the leachate is preferentially insolubilized to become a solid, and most of zinc ions and iron ions are dissolved in the leachate. That is, a manganese-containing precipitate (mainly manganese dioxide MnO ₂ ) and a zinc ion-containing solution (including a small amount of iron ions) are obtained.

  Note that the end point of the manganese oxidation reaction is determined by extracting a small part of the leachate during the ozone treatment periodically or continuously, separating the manganese oxide from the extracted liquid, and observing the color of the solution itself. It is preferable to determine the end point of the oxidation reaction of ions. Examples of means for separating the manganese oxide from the leachate include a means for filtration or sedimentation.

Second solid-liquid separation step In the second solid-liquid separation step, the manganese-containing precipitate (MnO ₂ ) obtained in the ozone treatment step and the zinc ion-containing solution (a solution in which manganese ions are precipitated from the leachate) are subjected to solid-liquid separation. To do. The solid-liquid separation means is not particularly limited, and may be any means selected from, for example, gravity sedimentation separation, filtration, centrifugation, filter press, membrane separation and the like. By the second solid-liquid separation step, each of the manganese component and the zinc component contained in the waste dry battery can be separated into a manganese-containing precipitate (MnO ₂ ) and a zinc ion-containing solution.

  Thus, the manganese component and the zinc component were mixed by going through each step of the sorting step, crushing / sieving step, acid leaching step, first solid-liquid separation step, ozone treatment step and second solid-liquid separation step. The manganese component and the zinc component can be extracted from the waste dry battery (powder particles) in a state where they are separated from each other. In addition, by treating with ozone, manganese can be separated not only from zinc but also from carbon mainly present in the residue, and a manganese oxide having a very high purity can be obtained.

  In the present invention, it is preferable to use the manganese precipitate obtained through the above-described steps as a raw material manganese-containing material. Thereby, high-quality metal manganese can be manufactured easily and stably.

  In addition, it goes without saying that the manganese precipitate obtained through the above-described steps contains moisture in the solid-liquid separation step, and is first dehydrated and dried. The method of dehydration / drying is not particularly limited, and any of conventional centrifugation, electric furnace heating, and the like can be applied.

  Examples of the reducing agent used in the arc melting furnace reduction process of the present invention include metallic aluminum, metallic silicon, and carbon. However, when producing high-grade metallic manganese, carbon that is easily mixed into metallic manganese (product). Is not suitable as a reducing agent for producing high-grade metal manganese, and is preferably metal aluminum or metal silicon.

  However, even when metallic aluminum or metallic silicon is used as the reducing agent, the graphite electrode and the charged material, particularly the molten metal (melted metal) produced by the reduction reaction, are heated and melted in the arc melting furnace. When contacted, it is inevitable that the carbon content in the molten metal produced increases to some extent.

  Therefore, in the arc melting furnace reduction process of the present invention, it is preferable to increase the distance (interval) between the graphite electrode and the charged material or molten metal, and to perform an operation (high voltage operation) that avoids contact. Thereby, it is possible to prevent carbon pickup from the graphite electrode.

Moreover, in the arc melting furnace reduction process of the present invention, it is preferable to perform a two-stage reduction including a primary reduction treatment and a finish reduction treatment. In the primary reduction treatment, MnO ₂ is reduced to MnO, metal Mn is not generated, and the Mn component is kept in the slag. On the other hand, in the finish reduction treatment, the reduction reaction is further advanced to obtain metal Mn. As a result, the contact between the electrode and the molten metal (molten metal Mn) can be minimized, and mixing of C into the metal Mn can be minimized.

  Furthermore, in producing high-grade metallic manganese, it is more desirable to use metallic aluminum as a reducing agent from the viewpoint of contamination with impurities.

  Furthermore, since a large amount of reaction heat is generated due to the aluminum thermite reaction, the metal aluminum uses a metal aluminum as the reducing agent, and when the reaction heat is generated by the reducing agent, heating by energization is performed. There is a concern of overheating. Therefore, in the present invention, while the heat of reaction of the reducing agent (aluminum thermite reaction) is generated, the energization heating by the electrode is stopped. Thereby, there is an advantage also from a viewpoint that the energization heating time by the graphite electrode can be shortened, and mixing of carbon into the product can be suppressed.

  Moreover, in the arc melting furnace reduction process of the present invention, when metal aluminum is used as the reducing agent, it is preferable to perform split charging in which the metal aluminum as the reducing agent is charged in a plurality of times. Thereby, the heat generated by the aluminum thermite reaction can be made uniform, overheating can be prevented, evaporation (blowing loss) of the molten metal (metal Mn) can be suppressed, and the Mn yield can be improved. When the reducing agent is dividedly charged, it is preferable to divide and charge the manganese-containing material and flux, or the raw material, as raw materials in order to make the reaction uniform.

  Moreover, it is preferable that the flux used in the arc melting furnace reduction process of the present invention is a substance mainly composed of CaO. Examples of the substance containing CaO as a main component include quick lime and limestone.

  When metallic aluminum is used as the reducing agent and quicklime CaO is used as the flux, in the arc melting furnace reduction process, the reducing agent and flux are blended so that the reaction proceeds according to the following formula, and is necessary for the reaction to proceed. Needless to say, the energization amount is adjusted so that a predetermined amount of heat can be secured.

MnO ₂ + 4/3 Al → Mn (metal) + 2 / 3Al ₂ O ₃ (3)
CaO + Al ₂ O ₃ → CaO ・ Al ₂ O ₃ (4)
Al ₂ O ₃ generated by the reaction of the formula (3) reacts with quicklime (CaO) in the reaction of the formula (4) to form slag. When slag is formed according to the formula (4), the free Al ₂ O _{3 in the} formula (3) disappears, so the reaction of the formula (3) proceeds from left to right, and manganese oxide (manganese-containing substance) ) Is reduced to promote metal manganese reaction.

  The compounding amount of the reducing agent is, for example, a reducing agent necessary for completely performing the reduction reaction represented by the above formula (3) (reduction reaction in which manganese oxide contained in the raw material manganese-containing material is manganese metal). More than the amount (theoretical reduction equivalent).

On the other hand, the blending amount of the flux is adjusted using the CaO / Al ₂ O ₃ ratio. The CaO / Al ₂ O ₃ ratio is 0.55, but good reaction progress can be obtained if it is in the range of about 0.4 to 1.0. If it is less than 0.4, manganese oxide in the slag cannot be reduced, and if it exceeds 1.0, free quicklime increases, the melting point of the slag becomes too high, and the amount of slag increases too much. For this reason, the blending amount of the flux is within a range of 0.4 to 1.0 in terms of the ratio (mass ratio) of the flux amount in terms of CaO and the amount of reducing agent in terms of oxide, and the CaO / Al ₂ O ₃ ratio. It is preferable to adjust so that.

  In the arc melting furnace reduction process in the present invention, it is preferable to perform a two-stage reduction of primary reduction and finish reduction. When metallic aluminum is used as the reducing agent, in the primary reduction, the reaction of the above formula (3), that is, the reaction until the formation of metal Mn is not advanced, but the reduction reaction to MnO, that is, the degree of oxidation is increased. The reaction to be reduced is limited and the reaction up to the formation of metal Mn is not allowed to proceed. For this reason, in the primary reduction, the amount of the reducing agent is a part of the total required amount. It goes without saying that the required amount of the manganese-containing substance as a raw material is added at the time of primary reduction. In addition, it is preferable that the blending amount of the flux is an amount suitable for the blending amount of the reducing agent. Then, in the finish reduction, the entire required amount of the remaining reducing agent is added together with the flux, and the reaction up to the formation of metal Mn is advanced.

  In the reduction reaction using metallic aluminum as the reducing agent, aluminum in the molten metal and manganese oxide (MnO) in the molten slag are in an equilibrium relationship. That is, when a reducing agent (aluminum metal) is excessively added exceeding the theoretical reduction equivalent (aluminum amount: 100) to increase the aluminum content in the molten metal (amount of aluminum in the metal), as shown in FIG. , Mn amount in molten slag (manganese amount in slag) decreases, Mn amount in molten metal increases, Mn yield (= (Mn amount in molten metal (metal Mn)) / (in raw material) Mn amount)) is improved. Moreover, when the aluminum content in the molten metal is increased, sulfur S in the molten metal is also reduced. This is probably because manganese sulfide (MnS) is also reduced. In addition, the present inventors have confirmed that adjusting the Al content in the molten metal to a range of about 1 to 3% improves the Mn yield and facilitates the reduction of S. However, when the aluminum content in the molten metal becomes excessively high, a problem arises in product quality. For this reason, it is preferable that the metal aluminum introduced as the reducing agent is within the range of 1 to 1.5 times the theoretical reduction equivalent.

  Hereinafter, the present invention will be described based on examples.

Example 1
A sorting process for sorting manganese batteries and alkaline manganese batteries from waste batteries, and a powder cake and sieving process for crushing the sorted waste batteries and sieving them with a sieve with a mesh size of 3.03 mm. Got. Table 1 shows the composition of the obtained granular material. In addition to the elements shown in Table 1, the obtained granular material contains oxygen and moisture derived from oxides and hydroxides.

  Next, the obtained granular material: about 800 kgf was subjected to an acid leaching step, a first solid-liquid separation step, an ozone treatment, and a second solid-liquid separation step under the conditions shown in Table 2, and a manganese precipitate (manganese oxide) ): About 250 kgf was obtained. Table 3 shows the composition of the obtained manganese precipitate.

  In addition, in order to obtain a comparatively large amount of manganese precipitate, the above-described steps were performed twice (treatment No. 1, No. 2). In total, about 500 kgf of manganese oxide (manganese oxide-containing substance) was obtained by dry treatment.

  In the obtained manganese precipitate, the content of elements other than Mn remains at a low level. Note that the slightly higher S is considered to be due to the influence of sulfuric acid used in the acid leaching process.

  Next, after drying the obtained manganese precipitate, an arc melting furnace reduction process was performed as a raw material (manganese oxide).

  The obtained manganese precipitate was charged into a test arc melting furnace as a mixed raw material together with a reducing agent and a flux. The charging was divided charging. An outline of the arc melting furnace reduction process is schematically shown in FIG.

  First, 5 kgf of energizing metal Mn was put into the furnace of the test arc melting furnace, the graphite electrode was lowered, and then the initial mixed raw material was charged. The composition of the initial mixed raw material was manganese precipitate: 25.0 kgf, metallic aluminum as a reducing agent: 6.0 kgf, and flux as CaO (quick lime): 8.2 kgf.

  After the initial mixed raw material was charged, electricity was applied and heated to dissolve the raw material. In addition, during melting, energization was stopped until the aluminum thermite reaction was completed.

  After completion of the aluminum thermite reaction, a predetermined temperature was secured, and power was supplied again to stably promote the reaction. This operation was repeated several times.

The composition of the additional mixed raw material was manganese precipitate: 25.0 kg, metallic aluminum as a reducing agent: 6.0 kgf, and flux as CaO (quick lime): 8.2 kgf. The amount of the reducing agent added so far was less than the theoretical reduction equivalent for producing metal Mn, and manganese dioxide MnO ₂ was reduced to manganese oxide MnO (primary reduction treatment). Further, after the primary reduction treatment, a reducing agent (including flux) was additionally charged and a finish reduction treatment was performed. The added reducing agent was metallic aluminum: 6.0 kgf, and the added flux was CaO: 9.0 kgf.

  In addition, after charging the additional reducing agent, the energization was stopped until the aluminum thermite reaction was completed to prevent overheating. After the aluminum thermite reaction was completed, the slag was sufficiently generated, and then the electrode was immersed in the slag, energized for a predetermined time, and subjected to a finish reduction treatment for promoting the reaction and adjusting the temperature. In the finish reduction treatment, the electrode was operated so as to avoid contact between the electrode and the molten metal to prevent carbon contamination.

  After the reduction treatment, the molten slag was discharged, and then molten metal (molten metal manganese) was poured into the mold and solidified. The obtained metal manganese was about 27 kgf.

  Table 4 shows the composition of the obtained metal manganese. In addition, in Table 4, the composition of the existing electrolytic manganese and extremely low phosphorus extremely low carbon ferromanganese was shown for reference.

The manganese metal obtained by the method of the present invention is not as high in pure manganese as electrolytic manganese, but has a lower S content than electrolytic manganese. Moreover, the metal manganese obtained by the method of the present invention has a higher manganese content than that of extremely low phosphorus, extremely low carbon ferromanganese, and has a low phosphorus and carbon content. In addition, although the metal manganese obtained by the method of the present invention has a high Al content, it has a sufficient composition as a manganese source for iron making. In the final stage of molten steel refining, metallic aluminum is added as a deoxidizing agent, and this level of aluminum content is not a problem as a manganese source for iron making.
(Example 2)
Using a commercially available reagent, manganese dioxide (Mn: 60% by mass) (total: 50 kgf) as a raw material, the same two-stage reduction treatment as in Example 1 was performed, and an arc melting furnace reduction process was performed. 26kgf was obtained. In addition, the reducing agent was metal aluminum as in Example 1, and the flux was quick lime. Table 5 shows the composition of the obtained metal manganese.

  It can be seen that the obtained metal manganese is a high-grade metal manganese having substantially the same composition as in Example 1.

Claims (10)

A method for producing metal manganese, which is obtained by subjecting a manganese-containing material to a reduction process, thereby obtaining metal manganese,
The manganese-containing material is a manganese-containing material obtained by subjecting manganese contained in a waste dry battery to acid leaching treatment, subjecting the obtained acid leaching solution to ozone treatment, and separation treatment.
In the reduction step, the manganese-containing material, and further a reducing agent and a flux are charged into an arc melting furnace, and the manganese-containing material is heated by heating and / or reaction heat of the reducing agent. reduced and manufacturing method features and to Rukin genus manganese to be the arc melting furnace reduction step of the metal manganese. Manganese contained in the waste dry battery is subjected to acid leaching treatment, the resulting acid leaching solution is subjected to ozone treatment, and the manganese-containing material obtained by separation treatment sorts the manganese dry battery and / or alkaline manganese dry battery from the waste dry battery. A crushing and sieving step for crushing and sieving the waste dry battery selected in the sieving step, obtaining a granule, a granule obtained in the crushing and sieving step, and an acid solution An acid leaching step of leaching manganese and zinc from the granular material by mixing with a reducing agent; and a first solid-liquid separation step of solid-liquid separating the leachate obtained in the acid leaching step and the leaching residue; An ozone treatment step in which ozone is allowed to act on the leachate separated in the first solid-liquid separation step to oxidize and precipitate manganese ions contained in the leachate, thereby obtaining a manganese-containing precipitate and a zinc ion-containing solution; A manganese-containing precipitate obtained through a step of sequentially performing a solid-liquid separation step of solid-liquid separation of the manganese-containing precipitate obtained in the ozone treatment step and the zinc ion-containing solution. method for producing a metallic manganese according to claim 1, wherein. In the arc melting furnace reduction step, a graphite electrode of the arc melting furnace, to increase the distance between the charge or molten metal, in claim 1 or 2, characterized by performing operations to avoid contact method for producing a metallic manganese described. The arc melting furnace reduction step is a two-stage reduction of primary reduction and finish reduction, the primary reduction is treatment to reduce the oxidation degree of manganese oxide, and the finish reduction is treatment to produce metallic manganese. method for producing a metallic manganese according to any one of claims 1 to 3, wherein. The reducing agent used in an arc melting furnace reduction step, the manufacturing method of the metals manganese according to any one of claims 1 to 4, characterized in that a metal aluminum or metal silicon. The metal aluminum, a manufacturing method of the metals manganese according to claim 5, characterized in that charged a plurality of times. Wherein while the metallic aluminum manganese reduction with is occurring, the production method of the metals manganese according to claim 5 or 6, characterized in that stopping the energization of the arc melting furnace. The charging amount of the metal aluminum, a manufacturing method of the metals manganese according to any one of claims 5 to 7, characterized in that 1 to 1.5 times the theoretical reducing equivalents. The flux used in an arc melting furnace reduction step, the manufacturing method of the metals manganese according to any one of claims 1 to 8, characterized in that a substance composed mainly of CaO. The manganese-containing material, manufacturing method of the metals manganese according to any one of claims 1 to 9, characterized in that the manganese dioxide.

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