JP2846149B2 - Production method of raw material oxide for ferrite - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a raw material oxide for ferrite.

[0002]

2. Description of the Related Art Usually, a ferrite manufacturing process is performed by using M
As shown in the manufacturing process of nZn ferrite, the main constituent metal elements iron, manganese, nickel, magnesium,
After mixing at a predetermined molar ratio an individual oxide such as copper, zinc or an oxalate which easily changes to an oxide by heating, a compound such as a carbonate, the mixture is calcined at a temperature of 800 to 1000 ° C. It is constituted by pulverizing to 1 to 2 μm, adding additives, further granulating, forming into a predetermined shape, and firing. However, this method has the following problems. (1) In order to mix and disperse a raw material oxide having a particle size of 0.1 to 1 μm, uniform mixing of the composition is not always sufficient, and the magnetic properties of the product are deteriorated. (2) Since the calcination process is performed at a high temperature of 800 to 1000 ° C., the cost increases. (3) In the calcination step, the magnetic powder grows to a particle size of 2 to 10 μm, and in the subsequent pulverization step, when mechanically pulverizing to about 1 μm, it takes a long time to pulverize, and the pulverization medium wears. Impurity contamination and composition deviation are inevitable.

[0003] In order to improve the above-mentioned problems (2) and (3) of the prior art, a ferrite production method using a mixed aqueous solution of a chloride of a metal element constituting ferrite as a starting material as shown in FIG. A production method for oxidizing and roasting the same has been proposed (JP-B-63-1777).
No. 6). However, even with this method, among the metal elements constituting ferrite, zinc and copper chloride having a high vapor pressure of chloride cannot be simultaneously oxidized and roasted. It is necessary to mix the components, and therefore, these components do not have sufficient uniform mixing properties of the raw materials, cause the composition to be non-uniform, and degrade the magnetic properties of the product. Was.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a method for producing a raw material oxide capable of producing ferrite having excellent characteristics at low cost.

[0005]

Means for Solving the Problems To achieve the above object, the present inventors have conducted intensive studies on an inexpensive and efficient method for producing a composite oxide for a soft ferrite raw material. A solution to the problem of volatilization during roasting of a component having a high vapor pressure as a product and nonuniformity and uneconomicity due to mechanical mixing at the time of post-addition was found, and the following invention was completed.

In other words, the method for producing a raw material oxide for ferrite of the present invention for achieving the above object comprises a chloride of iron (Fe) which is a main element constituting ferrite, manganese (Mn) and magnesium (Mg). , Nickel (Ni)
When a mixed chloride solution containing at least one selected from the group consisting of chlorides is oxidized and roasted at high temperature to produce a composite oxide, iron and another metal (one or more of manganese, magnesium and nickel) Is characterized by spraying a powder, a solution or a slurry with a compound that changes to an oxide such as zinc (Zn) oxide, or a carbonate or a hydroxide into a reaction region that changes its form into an oxide or spinel ferrite. Is what you do.

Here, when a compound that changes to an oxide such as a zinc oxide or a carbonate or a hydroxide is sprayed with a powder, a solution or a slurry, the timing of the spraying is determined by using iron and other metals (manganese, magnesium, nickel). (At least one of them) may be a position where the transition to the oxide form or spinel ferrite form is started or a position during the reaction. In addition, the mixed chloride aqueous solution and the powder, the solution or the slurry, from different positions in the roasting furnace, so that the spread of both sprayed material substantially overlap at any position from the spraying part to the furnace bottom. It is preferable to spray and oxidize and roast at the same time.

Further, the mixed chloride aqueous solution and the powder, the solution, or the like are arranged such that a position where the spread of the two sprays substantially overlaps is a position before the end of the oxidizing roasting reaction of the mixed chloride aqueous solution. Preferably, the slurry is sprayed.

[0009]

The present inventor has conducted intensive studies on a method for producing a raw material oxide capable of producing ferrite having excellent characteristics at low cost in order to solve the above-mentioned problems in the conventional example. In a roasting furnace, a chloride aqueous solution containing iron, manganese, nickel, magnesium, etc. is sprayed, and at the same time as this spraying, zinc and copper are added to a reaction region where the chloride aqueous solution changes into a form of oxide or spinel ferrite. By spraying powders, solutions or slurries of oxides or compounds that readily change to oxides upon heating,
The present inventors have found that it is possible to solve the problem of volatilization during the roasting of a ferrite component having a high vapor pressure as a metal chloride, and to produce an oxide raw material that can omit the calcination step in the ferrite production step. By doing so, the calcining and pulverizing steps can be omitted in the ferrite manufacturing process, and a ferrite core having excellent magnetic properties can be obtained.

Here, by optimizing the spraying conditions, the effect of the present technology can be maximized, and the uniform dispersibility of each component is improved, thereby further improving the magnetic characteristics and stability. Improvement can be achieved. That is, by setting the nozzle conditions so that the spread cross sections of the two sprays substantially completely overlap at any position from the spray section to the furnace bottom, each ferrite component in the finally obtained oxide is obtained. The uniform dispersibility of the elements is significantly increased. In addition, as will be described in detail in Examples described later, the position where the above-mentioned two types of sprays overlap with each other in the cross section is the furnace position before the end of the oxidative roasting reaction of chlorides such as iron, manganese, nickel, and magnesium. In this case, the spinelization reaction of zinc and / or copper can be promoted, and the problem of deformation and cracking of the core at the time of sintering in the later production of ferrite can be improved, and a greater effect can be obtained. I understood. As described above, in the present invention, extremely excellent uniform dispersibility of the microscopic ferrite component is achieved in the process of producing the raw material oxide.
Not to mention the advantage that the pulverizing step can be omitted, a great effect that excellent magnetic properties can be stably obtained in the obtained sintered ferrite core has been realized.

[0011]

The specific method of the present invention will be described below in detail with reference to examples. FIG. 1 shows a production flow of a composite oxide for Fe—Mn—Zn ferrite as the most common soft ferrite material. First, an aqueous solution of iron chloride, which is the main raw material for mixed roasting, is obtained as a hydrochloric acid pickling waste liquid such as a steel sheet in a rolling process of an ironworks, while an aqueous solution of manganese chloride is a manganese raw material such as metal manganese, ferromanganese or manganese oxide dust. Can be directly dissolved in hydrochloric acid or an aqueous solution of iron chloride. The Fe / Mn mixed chloride aqueous solution 2 is sprayed into the spray roasting furnace 1 by an ordinary method, and is oxidized and roasted at a high temperature of 650 to 900 ° C.

As a method for adding the zinc (Zn) raw material at this time, the amount of Zn necessary for the intended ferrite composition is supplied as one or more of zinc oxide, carbonate, and hydroxide. The method of supplying the zinc raw material 3 is a method of spraying a slurry of about 5 to 30 wt% from a spray nozzle,
In a powder state, compressed air is used as a carrier and an appropriate solid-gas ratio,
A method of spraying through a nozzle at a weight ratio of １２12 or the like is possible.

The supply position of the zinc oxide or the compound such as the carbonate and the hydroxide is a position where iron and manganese start transition from chloride to oxide or spinel ferrite (supply of iron and manganese). (Case 2 shown in FIG. 1), or a position where iron and manganese are in the process of transition from chloride to oxide or spinel ferrite (closer to the outlet of the roasting device than the supply position of iron / manganese). Position) (case 1 shown in FIG. 1), which is a region where the ambient temperature is 400 to 800 ° C. The added oxides of zinc and the like are treated with M during the oxidation or spinelization reaction.
n and Fe are uniformly mixed and dissolved, and ZnFe ₂ O ₄ , Zn
A reaction product such as Mn ₂ O ₄ (an intermediate to a single spinel phase) is efficiently produced. The fine powder of the metal oxide partially discharged together with the decomposition gas from the roasting furnace top is collected by the cyclone 4 and returned to the furnace 1 again.

The composite oxide powder 5 thus obtained
By adding a small amount of the additive 7 and directly firing at a high temperature in the firing furnace 6 after molding, it is possible to obtain a ferrite sintered core product 8 having excellent magnetic properties, no deformation or cracks, and high dimensional accuracy. As described above, homogeneous mixing, oxidation, and spinelization in a single roasting process of Fe / Mn / Zn can be performed, and the calcining and mechanical mixing of zinc raw materials, which are usually performed in the next process, can be omitted.

The soft ferrite product thus obtained is excellent in magnetic properties and dimensional accuracy. (Example 1) As an example, an iron raw material (steel pickling waste liquid: aqueous ferrous chloride solution) and a manganese raw material (solution of ferromanganese steel in hydrochloric acid) were respectively purified by filtration, and then mixed at a predetermined molar ratio. When an aqueous chloride solution was prepared, FeCl ₂ 34
2.7 (g / liter), MnCl ₂ 111.8 (g / liter)
Liters). This solution was supplied to a spray roasting furnace at a supply rate of 3.0 m ³ / hr, and when roasting at a body atmosphere temperature of 800 ° C., a ZnO suspension having a slurry concentration of 15 wt% was added to 0.55 m ³ / Hr supply temperature and ambient temperature 600 ° C
(Position of case 1 shown in FIG. 1) via a nozzle, the composition of the mixed oxide powder obtained from the furnace bottom was Fe: Mn: Zn = 68.2: 21.7: 1
0.1 (weight ratio), and no composition deviation was observed.
As a result of X-ray diffraction analysis, ZnFe
Reaction products such as ₂ O ₂ , FnMn ₂ O ₄ and MnFe ₂ O ₄ were detected.

The mixed oxide powder thus produced
In addition, CaCO_Three 800 ppm, SiO _Two 100 ppm
After adding and dissolving in pure water to make a 50% slurry liquid, wet
Mix with a triter for 20 minutes, skip the calcination step and spray
-Granulation by dryer, press forming to toroidal core
After firing at the maximum sintering temperature of 1300 ℃,
As shown in Table 1, the magnetic and electrical characteristics of the core
It turns out that it is excellent. (Comparative Example 1) As a comparative example, other than supply of ZnO into the roasting furnace
Is a mixed oxide of Fe / Mn manufactured in the same manner as in the above embodiment.
, ZnO is added afterwards so as to have the same composition ratio,
Object (CaCO_Three 800 ppm, SiO_Two 100 ppm)
After the addition, a wet attritor process is performed, and
When baked under the conditions shown, the magnetic properties of the obtained core
The electrical characteristics were as shown in Table 1.

[0017]

[Table 1]

(Example 2) A hydrochloric acid pickling waste liquid of a steel sheet was purified, and was further added and dissolved in 10 liters of a 100 ml solution to a concentration containing 30 g of iron at a rate of 1 kg of metallic manganese. Separately, a slurry containing 20% by weight of zinc oxide was prepared. These two types of liquids were sprayed and oxidized and roasted by using a spray roasting furnace under the respective spraying conditions shown in FIGS. In each figure, a nozzle of A was sprayed with a slurry of zinc oxide, and a nozzle of B was sprayed with a mixed solution of iron and manganese chloride.

Under the spray condition shown in FIG. 2, a nozzle having a spray angle of 30 ° inclined at 30 ° to the vertical line is 1.15 m.
They were opposed at intervals. The spread cross section of the spray droplets of both liquids was arranged so as to be almost completely overlapped at about 1 m below the spray position. As shown in the plan view of FIG. 3A and the elevation view of FIG.
Six nozzles with a spray angle of 30 ° arranged at the center of a nozzle A with a spray angle of 60 ° and a 15 ° angle to the vertical at 60 ° central angle intervals on a circumference of 0.84 m radius centered on the nozzle A FIG. 3 is a diagram showing a state where nozzles B are arranged. The spread cross section of the spray droplets of both liquids substantially overlaps about 2 m below the spray position.

FIG. 4 is a view showing a state in which the nozzle position and its conditions are set so that the overlapping position of the spread cross sections of the spray droplets of both liquids is about 4 m below the spray position. As a comparison with the present invention, a normal spray shown in FIG. 5 was also attempted. X-ray diffraction was performed on the oxidized and roasted powder obtained by spraying and oxidizing and roasting under the conditions shown in FIGS. 2 to 5, and as a result, the phases were identified.
In the method of FIG. 4 and the comparative example (FIG. 5), only a small amount of ZnO was observed in addition to e ₂ O ₃ and the spinel phase.

Also, 10 points of oxidized roasted powder samples were sampled at regular time intervals and subjected to chemical analysis. As a result, the target compositions of Fe ₂ O ₃ , MnO, and ZnO were obtained in the method of FIGS. Deviation was within ± 0.15 mol%, while in the case of the comparative example, variation exceeding 1 mol% was observed. SiO ₂ , CaCO ₃ , Nb
_After adding a small amount of additives of ₂ O ₅ and TiO ₂ , mixing with an attritor and further granulating, an outer diameter of 36 mm and an inner diameter of 24 m
m, and fired at 1340 ° C. in a nitrogen atmosphere containing 1% oxygen. The results of measurement of the core loss at 100 kHz, 200 mT, and 100 ° C. as magnetic properties of the obtained sintered core are shown in Examples 2 to 3 of the present invention in Table 2.

[0022]

[Table 2] Spray conditions Core loss mW / cm ^{3 The} present invention Example 1 FIG. 2 280 2 FIG. 3 275 3 FIG. 4 304 4 FIG. 2 290 Comparative Example FIG.か ら From these results, it is clear that very good magnetic properties can be obtained by applying the method of the present invention. In the case where the oxide obtained by the method shown in FIG. 4 was used as a raw material, slight cracks were sometimes observed in the sintered core, though very rarely. Further, considering that the core loss is slightly inferior to that of the method of FIG. 2 and that ZnO is detected in the generated oxide, the position where the spread cross sections of the spray droplets overlap is brought closer to the spray position. It can be concluded that the position is preferably before the oxidizing and roasting reaction of chloride is completed. Example 3 Purification used in Example 1 described above,
1 liter of metallic nickel in 10 liters of concentrated iron chloride aqueous solution
g was added and dissolved. Zinc oxide and copper oxide powder were added to pure water at a weight ratio of 3.5: 1 to produce a 20% by weight slurry liquid. These two types of liquids were oxidized and roasted using a spray roasting furnace by the spraying method shown in FIG. As a result, the purified oxide was composed of Fe ₂ O ₃ and a spinel phase, and the composition of each component oxide fluctuated within about 0.2 mol% of the target composition. This oxide was used as a raw material and granulated, formed into a toroidal shape having an outer diameter of 36 mm and an inner diameter of 24 mm, and then fired in an air atmosphere at 1150 ° C. As a result of measuring the frequency characteristics of the initial permeability of the obtained sintered core, good magnetic characteristics were obtained as shown in FIG. Example 4 20 kg of metallic manganese was put into 500 liters of a hydrochloric acid pickling waste liquid of a steel sheet concentrated to a concentration containing 15 g of iron in 100 ml and heated to 80 ° C. to completely dissolve the metallic manganese.

Further, 12.5 kg of zinc oxide was added to 25 parts of pure water.
Liter, and add ammonia to adjust pH to 12.5.
An aqueous solution was prepared. The aqueous solution obtained by dissolving the pickling hydrochloric acid in which iron and manganese are dissolved and an aqueous solution in which zinc oxide is mixed is sprayed into a spray roasting furnace maintained at 810 ° C. by the method shown in FIG. A powder was obtained. According to X-ray diffraction qualitative analysis, this oxide was Fe ₂ O ₃ , Mn ₂ O ₃ , and spinel.

From the chemical analysis, the composition of Fe, Mn and Zn is as follows:
Fe: Mn: Zn = 68.5: 22.8: 8.7 (weight ratio), indicating that a raw material oxide having no composition deviation was obtained. CaCO ₃ , SiO
₂ , 1000 ppm and 100 ppm of each were added, pure water was added, and the mixture was mixed by a rotary ball mill, granulated by a spray dryer, and then formed into a toroidal shape.
Calcination was performed in a nitrogen atmosphere containing 1% of oxygen at ℃. The magnetic characteristics of the obtained fired core are 100 kHz, 200 m
When the core loss at T and 90 ° C. was measured, 290 mW
/ Cm ² (Table 2 Invention Example 4)
reference).

[0025]

According to the present invention, when producing a raw material oxide for ferrite, it becomes possible to produce a composite oxide powder containing zinc and copper in the same roasting furnace, and a conventional post-process. Thus, the steps of adding and mechanically mixing the raw materials of zinc and copper can be omitted, and the quality characteristics of the ferrite core can be further improved. The improvement in the magnetic and electrical properties is explained by the improvement in the uniform dispersibility of the oxides constituting the ferrite, especially the oxides of zinc and copper.

Further, since the intermediate phase (ZnFe ₂ O ₄ ) generated in the conventional firing step is generated in advance, the volume expansion due to the formation of the intermediate phase during firing can be suppressed, and finally the firing is performed. A ferrite product having a high binding density and high dimensional accuracy without deformation or cracking can be manufactured.
As described above, the present invention has an effect that a high-quality powder mixed oxide for a ferrite raw material can be efficiently and economically produced.

Here, the present invention relates to a mixed metal containing iron chloride and at least one of manganese, nickel and magnesium chlorides having a low vapor pressure as a chloride among metal elements constituting ferrite. When oxidizing and roasting a chloride solution and a zinc and / or copper oxide or a compound that changes to an oxide in the same furnace, if the spraying conditions are appropriately selected, the components are more uniform. It has become possible to produce a ferrite raw material oxide dispersed in a steel.

As described above, by simultaneously reacting zinc and copper, which are one of the metal elements constituting ferrite, in the same furnace, (1) the calcination step is omitted and the cost is reduced.
(2) In the subsequent step after roasting, iron and manganese (or nickel, magnesium, etc.) and zinc and / or copper oxide etc. are roasted at once without mixing zinc and copper in the form of oxides. Due to the production in the kiln, the uniform dispersibility was improved, and as a result, the magnetic properties of the sintered core were also improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a method for producing a raw material oxide for ferrite of the present invention.

FIG. 2 is a view showing another example of the method for producing a raw material oxide for ferrite of the present invention.

FIG. 3 is a view showing still another example of the method for producing a raw material oxide for ferrite of the present invention.

FIG. 4 is a view showing still another example of the method for producing a raw material oxide for ferrite of the present invention.

FIG. 5 is a view showing a comparative example to be compared with the method for producing a raw material oxide for ferrite of the present invention.

6 is a graph showing measurement results of initial permeability of a sintered core manufactured using a raw material produced by employing the spraying method shown in FIG.

FIG. 7 is a view showing a ferrite manufacturing process according to a conventional method.

FIG. 8 is a diagram showing a ferrite manufacturing process according to another conventional method. Reference Signs List 1 roasting furnace 2 iron / manganese mixed chloride aqueous solution 3 powder, solution or slurry of zinc oxide, etc. 4 cyclone 5 Fe / Mn / Zn mixed oxide powder 6 firing furnace 7 trace additive 8 soft ferrite product

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenshi Takagi 1-chome, Mizushima-Kawasaki-dori, Kurashiki-shi (No address) Inside Mizushima Works, Kawasaki Steel Corporation (72) Inventor, Fumiaki Yoshikawa 1-chome, Mizushima-Kawasaki-dori, Kurashiki-shi (No address) (56) References JP-A-3-97625 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01F 1/34 C01G 49/00 C04B 35 / 622

Claims (4)

(57) [Claims] 1. A method of spraying a mixed chloride aqueous solution containing an iron chloride and at least one selected from manganese, magnesium and nickel chlorides into a roasting furnace.
Spraying zinc and / or copper oxide or a compound that changes to an oxide in a powder, solution or slurry state into the reaction region where the mixed chloride aqueous solution changes its form into an oxide or spinel ferrite. For producing a raw material oxide for ferrite. 2. A mixed chloride aqueous solution containing an iron chloride and at least one selected from manganese, magnesium and nickel chlorides, and a compound which changes to an oxide or an oxide of zinc and / or copper. Powders, solutions, or slurries are simultaneously sprayed from different positions in the roasting furnace at any position from the spraying section to the furnace bottom so that the spread of both sprayed bodies substantially overlaps, and oxidized and roasted. A method for producing a raw material oxide for ferrite, comprising: 3. Spraying the mixed chloride aqueous solution and the powder, solution, or slurry such that the spread of the two spray bodies substantially overlaps at a position before the oxidative roasting reaction of the mixed chloride aqueous solution is completed. The method for producing a raw material oxide for ferrite according to claim 1, wherein: 4. The method according to claim 1, wherein when the zinc and / or the oxide of steel or a compound that changes to the oxide is sprayed in the form of a solution or a slurry, the solution or the slurry is made alkaline. The method for producing a raw material oxide for ferrite according to any one of the above.