JPS62134220A - Manufacture of powder for ceramic material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing ceramic raw material powder used for making ceramics.

(Prior art) A method for obtaining a fine ceramic raw material powder by a wet synthesis method.
We proposed the content described in Publication No. 8263.

The method for producing this ceramic raw material powder consists of the following steps.

That is, in the first tank, carbon dioxide gas or a soluble carbonate such as soda carbonate or ammonium carbonate is added to an aqueous solution of nitrate or chloride containing at least one of Ba, Sr, Ca, and M9 as the C1 constituent element. Add aqueous solution and adjust CX)H to 7~
10, precipitated carbonate, and placed it in a second tank as 1QC% constituent elements [at least Ti,
Add a soluble hydroxide aqueous solution such as caustic soda or ammonium hydroxide to an aqueous solution of nitrate or chloride containing Zr, 8n, and Pb and adjust the CpH value to 7 to 10 by adding -J4.
A first step of precipitating C as a hydroxide, a second step of mixing 8 g of slurry containing each precipitate obtained in the step, filtration, washing with water, and drying, and mixing the resulting powder with water. This method consists of a third step of calcining and pulverizing.

In addition, #Kokai No. 59-195574, JP-A No. 5
Publication No. 9-195575, #open+iiH59-1955
Publication No. 76, etc. proposes a method for producing ceramic raw material powder using a wet synthesis method.

For example, in method B and C, a solution containing a precipitant such as charcoal and soda is added to a solution of Ba chloride [PHj is adjusted to 7 to 10 and tJI is increased by 4]. Carbonate precipitation [includes a step of precipitation]

(Problem to be Solved by the Invention) In the above steps, when a solution containing a precipitant is brought into contact with a solution containing a component of a ceramic material, the solution containing a precipitant is brought into contact with a solution containing a component of a ceramic material. A layer that occupies a small proportion of the total volume and width of the solution it contains. When contacted with a solution containing a C1 precipitant and a C1 precipitant, the pH value of the contacting part of the solution containing the constituent components of the ceramic material becomes very high;
The pH value of the contact area remains the same, but the pH value may vary greatly locally.

Further, as the solution containing the precipitant is added to the solution containing the constituent components of the ceramic material, the pkl value in the C1 reaction tank gradually changes. In the reaction stage, each product, that is, precursor, intermediate compound, and ceramic compound, is produced in chronological order, but the products produced in the early stages and those produced in the later stages are It was not preferable in that the powder properties of the two were different. Furthermore, the pH range at which the chemical species itself stably exists in each product,
If the pH value falls outside of that range, it may re-dissolve or chemical species with different composition ratios will be produced.

In this way, when a solution containing a precipitant is added to a solution containing ceramic constituents, the pH values of the parts that come into contact with each other vary greatly, resulting in the re-dissolution of the product once formed and the possibility of some bone formation. This will result in the regeneration of a product with a mismatched composition ratio.

(Objective of the Invention) The present invention provides a method for producing ceramic raw material powder that does not cause re-dissolution of the product during the reaction process or re-generation of products with a different composition ratio. The purpose is to

(Structure of the Invention) That is, to summarize the present invention, when introducing a first solution containing at least one ceramic component and a second solution containing a precipitant into a reaction tank, in the reaction tank: The first solution and the second solution are fed into the same reaction tank through separate routes so that the pH value is suitable for the precipitation conditions of the first solution and the second solution. At the stage where the solution is sent into the reaction tank, contact reaction and stirring and mixing are carried out in line I, and an example of an apparatus for carrying out the method of the present invention is explained in line 1 based on FIG.

Figure 1 shows the fist (, 1, 2 are at least 1 m away)
This is a storage tank for storing a first solution containing the above ceramic constituents and a solution containing a precipitant and leading to C1, and each storage tank 1, 2
A pipe 3.4 is connected to C, and a metering pump 5
．． 6, the first solution and the second solution are fed into the reaction tank 8 from the coupling pipe 7, and at this stage they are brought into contact. In the illustrated state, the first solution and the second solution are brought into contact in front of the reaction tank d, that is, in the coupling pipe 7, but since they are fed at a constant rate of J by the metering pump 5.6, C1 It is clear that the variation in pH value during the catalytic reaction is not a problem1^. The first solution and the second solution fed into the reaction tank 8 are connected to a motor 10, and a 1-stroke stirring mechanism 9 is connected to the motor 10.
Stirring and mixing are performed by.

This stirring blade 9 brings about a uniform mixing effect when viewed from a boiling point, and brings about convection circulation when viewed from a broader perspective.

The stirring blade 9 mixes at a flow rate of 171 to 54 g for 4 minutes (sparsely stirring). The first solution and the second solution that have been stirred and mixed are chronologically divided into the precursor 1 precursor - intermediate product 17 ramic. While passing through the steps of 1^ with the compound, the arrow Y is moved by the action of the stirring blade 9.
It is further sent in the direction of arrow X and discharged from the C1 delivery pipe 11. A slurry containing a production ratio IA4k is sent out within the via f11.

Obtained production ratio! The snout is collected after a filtration and washing process. For example, as shown in FIG. 2, such a precipitate is prepared by using the equipment shown in FIG. A composite oxide ceramic can be obtained by preparing each precipitate, B, and B in a predetermined ratio, and calcining the mixture. The composite oxide ceramics obtained at this stage include various ceramics such as barium titanate, strontium titanate, magnesium titanate, and zirconium titanate. Therefore, it is necessary to prepare a C-generating precipitate suitable for the composite oxide ceramic from which C1 is to be obtained.

(Effects) According to the method of the present invention, a first solution containing at least one ceramic component and a second solution containing a precipitant are mixed in a quantitative reaction tank so that the pH value is suitable for the precipitation conditions. Since the production ratio of 1ifI is obtained by feeding the components separately and stirring and mixing them at the same time as they are brought into contact with each other, the production reaction occurs one after another in the contact stage in a constant flow. , there is no pH value deviation, and there is no risk of re-dissolution of the product during the reaction process.
If a 1^ product with no deviation in the groove ratio is obtained, it will have a 1^ effect.

(Implementation PJ) Hereinafter, this invention will be described in detail according to examples.

Example 1: First, 2.000 μl of OJ-soluble barium salt such as barium chloride or barium nitrate was dissolved in 10 e of replenishing water.
Make the night, Ha, Co, Matashima (NH4) ICo,
A solution B was prepared by dissolving 7 moles of a precipitant consisting of 10 parts of replenishing water.

Pour each solution A and B into each reservoir and tubercle, and place them at intervals of 30 minutes, and then
Pumps are separately fed into the reaction tank while controlling the pH value in the reaction tank to be in the range of &5 to 19.5.
Solutions A and B were brought into contact reaction and simultaneously mixed by stirring in a reaction tank. At this stage, solution A and Bd reacted to produce a precipitate containing barium C.

On the other hand, 2.000 soluble titanium salts consisting of Ti1J
A solution C was prepared by dissolving 0t5JOuCt in 5t' of pure water, and a Js liquid was prepared by dissolving 10 moles of a precipitant such as NaOH, NH4OH, or KOH in 5g of pure water.

Each solution C, D is stored in each storage Id! , put it in a tank and use a running inlet pump.p)i It:6ts in the reaction tank
, s ~ one.

They were separately fed into a reaction tank while controlling the temperature to be within the range of 5, and were stirred and mixed in the reaction tank at the same time as Jmc and D were brought into contact reaction. At this stage, the solution C8D caused a reaction and a precipitate π containing C titanium was generated.

In this way, the precipitated sea urchin p of the 2-layer C and the precipitate ■ were mixed, and the washing and dehydration were repeated until no ce-'' remained.The powder obtained in this step was dried, 90
It was calcined at 0''C. This calcined powder was pulverized to obtain barium titanate (BaTiO*parramic powder).

The obtained ceramic powder was analyzed using a C1 transmission analytical electron microscope aWl with a spot diameter of 1 μm and the molar ratio at the point of 10 (r!A) was selected appropriately.
The table shows the measurement results of the ratio.

Table 1 As is clear from Table 1, according to this actual winding process, the powder for ceramic raw materials obtained (8'C1 is almost always mixed with I without any deviation in molar ratio). decrease.

In the above implementation series, barium titanate (BaTiO,) was explained first. However, it is also possible to contain one or more of Sr, Ca, mn, etc. in addition to Ba. In addition to T1, Zn, Sn, C8, L%,'
l) It is also possible to include 14 or 2 or more species such as eMn. In addition, Mn to Tsul' (is Ba1
11. It is noted that 18, which is present on either side of Ti-, is included in both, and C is also added to 1.

Example First, 2.000 moles of soluble pallium salts such as barium chloride and barium nitrate were added to 10 tons of pure water! Prepare solution E dissolved in Na! A solution F was prepared by dissolving 7 moles of a precipitating agent consisting of Go or (NH,)l cos in 10&' of pure water.

Put each solution and P into each storage tank and add them to the reaction tank separately using a metering pump. The solutions ffi and P were brought into contact and reacted, and at the same time, they were stirred and mixed in the reaction tank. Solution A at this stage.

? A reaction occurred and barium C was removed, and a precipitate (2) was produced.

On the other hand, TlCl4. Zr0C1,? 9H,O,5nC1
,.

Bi(No, ), -5H,O salt 1!31:2.00
4 moles and H,O.

5oocc of pure water 1ogVca41. A solution G was prepared, and a solution H was prepared by adding 1 mole of a precipitant such as NaOH, NH4OH, or KOH to 511 Ca of water.

Put each solution G and H into each RWI and place C, and use a metering pump to make the pH value in the reaction tank 1/-% C
a! The solutions were separately pumped into the reaction tank while being controlled so that the solution G and H were brought into contact with each other, and at the same time, they were stirred and mixed in the reaction tank. At this stage, solutions G and H start to react and Ti,
Precipitate 11J and HIBN containing Zr, an, and Bi were produced.

9”, N a Of(, N B 40 H, l-O
A solution J was prepared by dissolving 1 mol of a precipitant such as H in pure water 11&C.

Each solution engineering, J to each house! 1. ．． lI! Put it in the tank and set it at C, and the metering pump is equipped with +4 (the p'H value in the reaction tank is 8.
The mixture was controlled to be in the range of 5 to 1'1.5, and then sent separately to the reaction tank, and at the same time as the solution and J were brought into contact with each other, they were stirred and mixed in the reaction tank for 4 hours. At this stage? After 81 hours of operation, a precipitate kV containing J (Pl), which caused the reaction, was produced.

In this way, three types of precipitates were obtained.

V was mixed, and washing and dehydration were repeated until no CIEE remained. After this royal power, dry the powder obtained and
oar: Temporarily fired. This calcined powder is crushed with Zr,
Barium titanate (B) containing Sn, Bi, Pb
A ceramic powder of a T i O,) was obtained.

The obtained ceramic powder was subjected to A-type analysis at 11011i locations with a spot diameter of 1 μm.
The molar ratio in terms of CU was selected and analyzed. Table 2 shows the results of measuring molar ratios.

Table 2 As is clear from Table 2, according to this example, ceramic raw material powders with almost no deviation in molar ratio were obtained. Ru.

In the above example, the ceramic raw material powder was prepared by mixing and calcining three types of precipitates.
Precipitates of 3s or higher are generated, mixed and calcined [
It is also possible to obtain powder for ceramic raw materials.

Example 3 First, a solution K was prepared by mixing 2.000 moles of a soluble salt consisting of Ti(J4) and HzOx500CC in 14 water (5#4!4) for titanium chloride, and Na0j(, KOH, N
I in which 10 mol of a precipitant such as H4OH was dissolved in pure water 5e
I made a solution.

At night, put F and L in each house R4 and place C, and use a running feed pump.The pH in the reaction tank is 8.5 to 1.

They were separately fed into a reaction tank while controlling the temperature to be within the range of 5, and at the same time as the L was brought into contact with the solution, they were stirred and mixed in the reaction tank for 4 times. At this stage, a precipitate 5 was produced in the solution, in which L was subjected to a precipitation reaction and C was removed from titanium.

On the other hand, soluble barium such as barium chloride or barium nitrate, rJ [2,000 mol, was dissolved in 10 g of pure water to make a molten iM, and Na, Cos or (NHa) snow CO
A solution N was prepared by dissolving 7 moles of a precipitant consisting of S in 101 K of pure water.

Put each solution M and N into each storage tank, and use a metering pump until the pH value in the 18C reaction tank is 8. The slurry of the precipitate (2) containing titanium produced earlier is fed into the reaction tank through the running feed pump (1).

At this time, in the reaction 1, the W solution M and the solution N come into contact and are simultaneously stirred and mixed in the reaction tank, while the slurry of the precipitate 5 containing titanium also enters the reaction 1 at the same time. The slurry of precipitate (2) containing titanium is fed into the reaction tank so that the supply ends at the same time as the precipitation reaction of solutions M and N ends.At this stage, barium and titanium are A precipitate (■) containing is formed.

The precipitate thus obtained at °C was washed and dehydrated repeatedly until C4- was eliminated. After this process was carried out, the resulting powder was photographed and calcined at 900°C.

This calcined powder was pulverized at °C to obtain barium titanate (BaTi).
e,) ceramic powder was obtained.

The obtained ceramic powder was analyzed using a C1 transmission analytical electron microscope at 10 appropriately selected locations with a spot diameter of 1 μm, and the molar ratio at those points was analyzed.

Table 3 shows the results of measuring the molarization of .e.

As is clear from Table 3 and Table 5, according to this example, the obtained ceramic raw material powder had almost no deviation in the molar ratio of C1 to C1. ＾ru.

In this example, the explanation was given for barium titanate (BaTiO,), but in addition to Ba, 1f! ! C is good by containing two or more types of i-1, and C is also good by containing Zn, an, Ce, La, Nb, Mn, etc. in addition to T1ε.

To summarize this example, a first solution containing at least one ceramic component and a second solution containing a precipitant are mixed at a pH value suitable for the precipitation conditions in the reaction vessel. B are sent into the same reaction tank through separate routes, and contact reaction and stirring mixing are performed at the step of sending the first solution and the second solution to the reaction tank. The first step is to prepare the solution, and in the next step, a third solution containing at least one ceramic constituent different from the ceramic constituent contained in the first solution and a third solution containing a precipitant are added. The solution in step 4 is treated in the same manner as in the first step, except that the step in which the fifth solution and the fourth solution are fed into the reaction tank and subjected to contact reaction and mixing by stirring is carried out in the first step. A step consisting of feeding a slurry containing a refined ceramic compound into a reaction tank so that the supply ends at the same time as the precipitation reaction between the third solution and the fourth solution ends. It is.

Comparative Example: First, ammonium carbonate ((NH4) and gourd were added dropwise to an aqueous solution of BaC#i in the first tank to bring the CpH value to 9~9.
The temperature was adjusted to 9.5, and BaCO5 was used to precipitate C.

In addition, 15 mt of 30% hydrogen peroxide solution, which is a stabilizer, was added dropwise to the aqueous solution of TiCl4 in the second tank, and then ammonium hydroxide (NH40H) was added at °C to adjust the pH to 9 to 9.5. The precipitate and proboscis containing T1 were obtained.

The slurries of each precipitate were mixed, filtered, and washed with water.

The water-washed raw materials are mixed in a ball mill, followed by filtration,
It was dried and further calcined for 1 hour at a temperature of 900C to obtain a calcined powder of barium titanate (BaTiO,).

This calcined powder was analyzed using a transmission analytical electron microscope at 1°C at 10 points with a spot diameter of 1 μm, and the molar ratio at that point was analyzed. Table 44 shows the results of measuring molar ratios.

Table 4 According to this comparison column from Table 4, the molar ratio at each analysis point varied greatly, and ceramic powder was obtained near the r* value of 1. This can be considered to be due to large local differences in pH values at the contact reaction stage.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an example of an apparatus for carrying out the method of the present invention. Fig. 2 shows the process of using the produced precipitate containing the constituent components of the ceramic obtained by the method of the present invention to 1 (4 cases) and calcination. 1 and 2 are storage vessels, 3 .4 is the pipe% 5.6 is the constant feeding pump, 7 is the coupling pipe, 81 is the reaction tank, 9 is the stirring blade,
10 is a motor.

Claims (2)

[Claims] (1) When introducing the first solution containing at least one ceramic component and the second solution containing a precipitant into the reaction tank, the pH value is suitable for the precipitation conditions in the reaction tank. As shown in FIG. 1. A method for producing powder for ceramic raw material, which comprises stirring and mixing to obtain a ceramic precipitate. (2) Two or more types of ceramic raw material powder obtained based on the above process are prepared, and each of these ceramic raw material powders is mixed in a predetermined ratio and then calcined. ) A method for producing a powder for ceramic raw materials as described in item 2.