JPH0431324A - Production of aqueous solution of mixed iron and manganese chloride - Google Patents

Abstract

PURPOSE:To obtain the subject aqueous solution useful as a raw material for multiple oxides for ferrite raw material in high purity and efficiency by adding a manganese oxide to an aqueous solution of ferrous chloride having a specific pH and removing the suspended materials and precipitates from the solution. CONSTITUTION:An aqueous solution of ferrous chloride is adjusted to pH 1-4 and a manganese oxide is added to and dissolved in the solution to effect the substitution reaction of metal oxides. The manganese oxide may be inexpensive manganese oxide fine powder produced as a by-product in the oxygen-refining process of an iron-manganese alloy. Manganese can be dissolved in a short time in high efficiency and impurities such as Si, Al, Cr, P and B can be separated by coprecipitating with and adsorbing to iron oxide particles. Accordingly, a mixed solution of iron chloride and manganese chloride having high purity can be produced in high efficiency at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing a mixed chloride solution of metals constituting ferrite, which is a raw material when producing a composite oxide for ferrite raw material. More specifically, the present invention relates to a method for producing an iron and manganese mixed chloride aqueous solution with few impurities using a ferrous chloride aqueous solution as a raw material.

<Prior Art> The industrial method for manufacturing ferrite is to mix compounds such as oxides or carbonates of metals such as iron, manganese, and zinc that constitute ferrite in a predetermined molar ratio, and to perform calcination (preliminary firing),
It is common to go through pulverization and molding steps, and then finally sinter at a high temperature. However, this method requires a relatively high-temperature and long-term calcination step, which not only affects quality, such as the introduction of impurities during the manufacturing process and non-uniformity of quality when viewed microscopically. There are problems in that it takes a long time to manufacture and requires a large amount of energy.

In general, the iron oxide raw material that occupies the largest proportion in the ferrite raw material composition is often obtained by oxidizing and roasting waste fluid from hydrochloric acid pickling of steel sheets in the rolling process of steel mills. Therefore, as a ferrite manufacturing method that improves the conventional technology, a manufacturing method has been proposed in which a mixed solution of metal chlorides constituting ferrite is used as a starting material and is oxidized and roasted (Japanese Patent Publication No. 47-11550, 63-
No. 17776). The mixed oxides produced by such oxidative roasting are uniformly mixed on a microscopic scale, which improves the uniformity of the composition in the process of manufacturing ferrite, making it possible to shorten or eliminate the calcining process. It is said that it can be done.

However, when obtaining a mixed chloride solution as a raw material, especially a manganese chloride solution, there is no mention of the purification (removal of impurities) method;
In No. 0, electrolytic manganese dissolved in hydrochloric acid is used, and in Japanese Patent Publication No. 63-17776, it is possible to use manganese chloride dissolved in water or metallic manganese dissolved in hydrochloric acid. It has been stated.
However, such raw materials are usually in the form of lumps when obtained, have low dissolution efficiency in hydrochloric acid, and require additional steps such as pulverization. In addition, these raw materials are generally expensive and cannot be said to be advantageous from an economic standpoint. Furthermore, the generation of H2 may also become a problem.

<Problems to be Solved by the Invention> As described above, in the method of producing powdered oxide for ferrite raw material by roasting a mixed solution of iron chloride and manganese chloride at high temperature, conventionally, metals were used as manganese raw material. Manganese or manganese chloride was prepared by dissolving it in hydrochloric acid, but there were problems such as very high raw material costs, poor dissolution efficiency, and a long time required for dissolution.

Therefore, the present invention eliminates the drawbacks of the prior art as described above, and efficiently and inexpensively produces a highly pure iron and manganese mixed chloride aqueous solution that does not contain impurities such as Si, An, Cr, P, and B. The purpose is to provide a method.

Means for Solving the Problems> In order to achieve the above object, the present inventors have conducted intensive research on an inexpensive and efficient method for purifying manganese chloride solution, and have found that Manganese oxide fine particles [manganese oxide (MnO), dimanganese tetroxide (MnsL), dimanganese trioxide (Mn
By dissolving particles such as Sj, A
Impurities such as j2, Cr, P, and B are removed by iron oxide particles [iron oxide (Fed), triiron tetroxide (Fe
We discovered that a highly pure mixed solution of iron chloride and manganese chloride can be prepared efficiently (and inexpensively) by co-precipitating and adsorbing it on particles such as sO4) and diiron trioxide (Fe5os), and published this book. The invention was completed.

That is, the present invention provides a method for producing an iron and manganese mixed chloride aqueous solution, which is characterized by adjusting the ferrous chloride aqueous solution to pH 1 to 4, adding manganese oxide, and then removing suspended matter and precipitates. The present invention provides a method.

The present invention will be explained in more detail below.

First, fine particles of manganese oxide [manganese oxide (MnO), dimanganese tetroxide (Mn
iL), particles of dimanganese trioxide (MnaOs), etc.] can be obtained, for example, as follows. Ferromanganese alloys (ferromanganese alloys) are usually added during the steelmaking stage of the steel industry for purposes such as deoxidation and desulfurization.
In the process of carbonization, ferromanganese is refined by blowing oxygen or an oxygen-containing gas into the molten metal. At this time, since manganese has a much higher vapor pressure than iron, it evaporates and combines with oxygen to become fine oxide particles with an average particle size of several microns or less. These oxide fine particles were collected using a cyclone or a bag filter, and recycled as raw materials, or some were used as raw materials for glazes and the like. Such manganese oxide fine particles have good solubility in acids because they are fine particles, but their contained components include SL, A℃
, Cr.

If these impurities such as P and B remain in ferrite products, they will significantly impair their electrical and magnetic properties, so it is difficult to use them directly as ferrite raw materials, and it is difficult to refine (remove impurities) and make imitations. It was necessary.

On the other hand, as for iron raw materials, waste liquid from hydrochloric acid pickling of steel plates (ferrous chloride aqueous solution) is often used in the rolling process of steel mills, but it still contains the impurities mentioned above. Depending on the purpose of use, it was purified and used by methods such as coagulation, filtration and separation, or crystallization.

The present inventors used the following formulas (], ), (2) and (3) to prepare a highly pure Fe/Mn mixed chloride solution using such manganese and iron raw materials.
The metal oxide substitution reaction as shown in
Iron oxides [iron oxide (Fed), Fe tetroxide (Fe
It has been found that the impurity content in the solution can be significantly reduced by co-precipitating and adsorbing it onto particles of triiron trioxide (FeJs) and separating it.

Mn0(S)+2eC1-(L) 1 = MnC11(L)+Fe0(Sl ↓ -(
11MnsD, (S)+3FeC1z(L)-43Mn
Cl2(L)+Fe3O4(S)↓−(2)Mn,O,
(S)+2FeC1-(L)=2MnC1a(L)+
FeJ-(S')i-(3) The iron oxide particles produced by the method of the present invention have the following unique characteristics. In other words, it is porous in structure and has a large contact surface area that contributes to co-precipitation and adsorption of impurities, and it is also positively charged in the liquid, so it cannot be used with negatively charged materials such as silica (SiO□) monomers and polymers. It has the effect of charge-neutralizing and flocculating substances (lowering the zeta potential), and it can be easily flocculated with a polymer flocculant and has excellent sedimentation or filtration separation properties.

To describe the specific content of the present invention in detail, first, as a pretreatment, the waste solution from hydrochloric acid pickling of steel plates (ferrous chloride aqueous solution) is neutralized with inexpensive iron or manganese materials such as scraps and scales to lower the pH. Adjust to 1-4. Normally, the raw material liquid contains free acid and is often in a strongly acidic state where r+H is less than O, but by increasing the pH to 1 or more, the following effects can be obtained.

(1) Facilitate the manganese dissolution (metal oxide substitution) reaction of formulas (1) to (3).

(2) Colloidally polymerize SiO□ to insolubilize it into a form that can be easily separated by filtration.

(3) The oxides of P and B are transferred to a poorly soluble body and made insoluble.

(4) Metals such as Aff, Cr, Cu, and Ti are precipitated as hydroxide precipitates.

In this way, pH adjustment promotes the metal oxide substitution reaction and insolubilizes and precipitates impurity elements (makes them in a form that is easy to separate).
It is carried out for the purpose of

Note that it is not preferable to use an alkaline agent for pH adjustment because it adds impurities to the system. Therefore, iron or manganese materials are recommended as neutralizing agents (particularly in the case of metal iron such as scrap, it reduces the trivalent iron (Fe'') present in small amounts in the raw solution (formula (4)), so the pH It is advantageous for climbing.

2/3FeC1s fL) +1/3Fe (S) →
FeC1a (L) - (4) Furthermore, under conditions of pH > 4, in addition to the problem that adjustment takes a long time, some of the divalent iron (Fe'') in the solution begins to precipitate. Therefore, it is unsuitable due to Fe loss.The processing temperature is 6
The reaction proceeds rapidly at 0°C or higher, preferably 80°C or higher.

Next, the conditions for the metal oxide substitution reaction (formulas (1) to (3)) are as follows: treatment temperature is preferably 50°C to 100°C, preferably 70°C to 90°C, and pH and H are adjusted under stirring conditions. The reaction proceeds while holding.

The Fefi degree of the ferrous chloride aqueous solution as a raw material is arbitrary, but from an economical point of view, high concentration (Fe≧200 g /
1) is advantageous.

The addition ratio of the Mn raw material (oxide fine particles) can also be set depending on the purpose, but when using it as a raw material for ordinary M n /Z n ferrite, the M n /Fe ratio = 1 /
/4 to 1/3 is often used. Under such conditions, the reaction is completed within one hour by adding the required equivalent amount of Mn. Furthermore, this reaction is preferable from the viewpoint of safety because it does not involve the generation of reactive gas such as H2 gas.

In addition, the precipitate generated in this reaction was determined by X-ray diffraction analysis to include iron oxide (Fed), iron tetroxide (Fe304),
It has been confirmed that the particles are trioxide iron pig iron (Fears), and as mentioned above, the characteristics of the fine particles make them very desirable as carriers for coprecipitation and adsorption treatment. It is also effective to add about 5 to 30 ppm (mg/l) of a polymer flocculant to promote flocculation and separation of the precipitate. The precipitate after coagulation is discharged out of the system as a filter cake by ordinary means such as sedimentation separation and filtration separation.
The iron oxide particles separated in this manner contain a large amount of impurities, but can be used for hard ferrite, pigments, etc.

As described above, the present invention provides p
A major feature is that not only the Mn raw material but also the Fe raw material can be purified at the same time by combining the impurity insolubilization effect by H adjustment and the coprecipitation/adsorption effect using iron oxide particles as a carrier. This can be expected to greatly contribute to cost reduction and process simplification of raw material preparation and purification steps. The highly pure mixed solution of iron chloride and manganese chloride thus obtained can be roasted at a high temperature and used as a powdered composite oxide for high-grade ferrite raw materials.

An example of a specific implementation flow of the present invention will be explained based on FIG. 1.

The raw material ferrous chloride aqueous solution is charged into a pH adjustment tank 1, and iron and manganese materials (for example, metal iron such as scrap) are added to neutralize it and adjust it to p)l = 1 to 4. . Next, the mixture is transferred to the manganese dissolution reactor 2, where a predetermined amount of manganese oxide particles are added and mixed. Furthermore, after adding and mixing a polymer flocculant as necessary, the iron oxide particles that coprecipitate and adsorb impurities are sedimented and concentrated in the thickener 3, dehydrated and separated in the filter breath 4, and sent out of the system as a cake. Discharge.

On the other hand, the clarified liquid from the thickener 3 passes through a clarification filter connection 5 to obtain a purified mixed chloride solution of iron/manganese. This liquid mixture is oxidized and roasted in an oxidation roasting furnace 6 to become a highly pure iron/manganese mixed oxide. Furthermore, it is mixed with auxiliary raw materials and fired in a high-temperature firing furnace 7, resulting in a high-performance ferrite product.

<Example> The present invention will be specifically explained below based on Examples.

(Examples 1 to 3) Manganese oxide fine particles (manganese tetroxide (Mns) generated during the oxygen smelting process of iron-manganese alloys as shown in Table 1
The starting materials were O4) particles) and an aqueous ferrous chloride solution generated as a waste solution from hydrochloric acid pickling of steel plates. All of them contain impurities as shown in the table.

First, 1 liter of iron chloride solution was filled with iron material (scrap pieces of cold-rolled steel sheets generated in steel mills) at least 5 times the theoretical consumption amount, and heated to 75°C in a batch-type melting tank. Stir for 5 hours and 3.5 hours to adjust the pH to 2.2.3.
．． 2 to neutralize all free hydrochloric acid in the raw material and reduce the small amount of Fe'' present to the total amount of Fe''.

Next, after taking out the liquid and separating it from the scrap pieces, Mn
While maintaining the liquid temperature in the dissolution tank at 75-80℃, add the same amount (
Manganese oxide fine particles (manganese tetroxide (Mn5L) particles) with Fe/Mn = 1/4 to 1/3) were added and stirred for 1 hour to perform a metal oxide substitution reaction (see Table 2). . Further, an anionic polymer flocculant was added to the raw material solution at a ratio of 10 mg/l, and after stirring for 10 minutes, the mixture was left to stand and sedimented to separate magnetite sludge.

On the other hand, the supernatant liquid was filtered through a filter with a pore size of 1 μm to obtain a final purified liquid, an Fe/Mn mixed solution.
Furthermore, from the component analysis values of the obtained Fe/Mn mixed solution, mixed oxide (x-Fezes y・Mn5Os
) Table 3 shows the content of impurity components converted to the base.

Furthermore, as an example, the rate data of the metal oxide substitution reaction in Example 1 is shown in FIG.

(Comparative Example 1.2) Using the same raw materials as in the previous example, the liquid obtained by simply dissolving manganese oxide fine particles in hydrochloric acid was chlorinated without performing the purification operation as in the example of the present invention. In the case where the manganese oxide fine particles were simply mixed with the ferrous aqueous solution [Comparative Example 1], in the case where the manganese oxide fine particles were dissolved in hydrochloric acid, a flocculant was added, and only the filtration separation was carried out [
Table 3 shows the component analysis results of Comparative Example 2].

In addition, Comparative Example 2 is an example in which the Fe/Mn chloride aqueous solution was subjected to flocculation and filtration separation treatment shortly after mixing.
The results were the same even when the aqueous Mn chloride solutions were treated separately. From this, it is clear that the content of impurity components is higher than that in Examples.

For comparison, when electrolytic metal manganese (pulverized lumps of about 3-10 mm) was dissolved in hydrochloric acid, M n 15
It took a long time of 1°hr or more to obtain a 0 g/1 solution.

Table 1 Raw material composition Table 2 As is clear from the above implementation conditions, if operated as in the present invention, M
The n-component can be rapidly dissolved, and impurities such as Si, Aj2, Cr, P, and B can be removed efficiently and economically.

Furthermore, in the examples, trimanganese tetrafluoride dust powder was used as a representative example of manganese oxide fine particles, but similar results were obtained using other manganese oxide and nimanganese trioxide particles.

Table 3 Implementation Results <Effects of the Invention> Since the present invention is configured as explained above, it is possible to obtain a mixed chloride solution of Fe/Mn with high purity at low cost and efficiently. By roasting at a high temperature, it can be used as a powder mixed oxide for high-quality ferrite raw materials.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a flow for implementing the method of the present invention. 3 is a diagram showing rate data of metal oxide substitution reaction in Example 1 of FIG. 2. FIG. Explanation of symbols 1...pH adjustment tank, 2...manganese dissolution reactor, 3...thickener 4...filter press, 5...clarifier filter connection, 6...oxidation roasting furnace ( Spray roasting furnace) 7...High temperature firing furnace

Claims (1)

[Claims] (1) A method for producing an iron and manganese mixed chloride aqueous solution, which comprises adjusting the ferrous chloride aqueous solution to pH 1 to 4, adding manganese oxide, and then removing suspended matter and precipitates.