CN117645538A

CN117645538A - Method for preparing alkali-catalyzed superfine barium titanyl oxalate and method for preparing barium titanate

Info

Publication number: CN117645538A
Application number: CN202311364464.6A
Authority: CN
Inventors: 陆小明; 张泰林; 占伟东
Original assignee: Yuanjie New Material Technology Zhejiang Co ltd
Current assignee: Yuanjie New Material Technology Zhejiang Co ltd
Priority date: 2023-10-20
Filing date: 2023-10-20
Publication date: 2024-03-05

Abstract

The invention relates to the technical field of ceramic raw materials, and discloses a method for manufacturing alkali-catalyzed superfine barium titanyl oxalate and a method for manufacturing barium titanate, which comprises the following steps: s1, selecting raw materials; s2, mixing raw materials; s3, curing reaction; s4, adding a solution; s5, regulating the pH; s6, carrying out solid-liquid separation to obtain powder, dissolving a titanium compound and an oxalate compound in an organic solvent, adding a surfactant to the solution A to obtain the solution A, mixing the solution B with the solution B, inhibiting the growth of crystal grains by the space barrier action of the surfactant and an alkaline solution to obtain ultrafine barium titanyl oxalate, obtaining high-crystallization barium titanate at a lower temperature, wherein the obtained barium titanate has a particle size distribution below 700nm, and obtaining barium titanyl oxalate of barium titanate with small particle size distribution and high crystallinity by an oxalate method after improvement, and the method can be used for preparing the barium titanate in large quantities industrially.

Description

Method for preparing alkali-catalyzed superfine barium titanyl oxalate and method for preparing barium titanate

Technical Field

The invention relates to the technical field of ceramic raw materials, in particular to a method for manufacturing alkali-catalyzed superfine barium titanyl oxalate and a method for manufacturing barium titanate.

Background

Currently, barium titanate is mainly synthesized and manufactured by a solid phase method, a hydrothermal synthesis method, a sol-gel method, an oxalate method, and the like.

In the solid phase method, since the solid phase method is produced by a dry method in which constituent raw material powders and the like are mixed and the mixture is heated at a high temperature, the obtained powder forms aggregates exhibiting irregular shapes, and high-temperature firing is also required to achieve desired characteristics. Although the hydrothermal synthesis method has the advantage of good powder properties, it is complicated in the synthesis process and uses an autoclave, and therefore, productivity is poor, and the cost for producing the powder is high.

Disclosure of Invention

The invention aims to provide a method for manufacturing alkali-catalyzed superfine barium titanyl oxalate and a method for manufacturing barium titanate, so as to solve the problems in the prior art.

In order to achieve the above purpose, the present invention provides the following technical solutions: the preparation process of alkali catalyzed superfine barium titanyl oxalate includes the following steps:

s1, selecting raw materials;

s2, mixing raw materials;

s3, curing reaction;

s4, adding a solution;

s5, regulating the pH;

s6, carrying out solid-liquid separation to obtain powder.

Preferably, in S1, the raw materials are a liquid a, a liquid B, and a liquid C;

the solution A is a solution containing a titanium source compound, an oxalate compound and a surfactant;

the solution B is a solution containing a barium source compound;

the solution C is an alkaline compound solution.

Preferably, in S2, the solution a is added to the reactor while stirring the solution a, and the solution B is added to the solution a, and the time required for the uniform mixing is 1 to 2H.

Preferably, in S3, the time for the aging reaction is 4 to 8H, and the reaction temperature is 40 ℃ or lower.

Preferably, in S4, the liquid C is added to a mixed solution of the liquid a and the liquid B.

Preferably, in S5, the solution C is added until the pH of the mixed solution is 5 to 6; the powder obtained by solid-liquid separation is barium titanyl oxalate.

Preferably, the liquid a is an organic solvent;

the solvent of the solution A is one of methanol, ethanol, butanol or glycol;

the titanium source compound in the solution A is one of titanium trichloride or titanium tetrachloride;

the oxalic acid radical compound is one of oxalic acid, ammonium oxalate, sodium oxalate or potassium oxalate;

the surfactant is one of dodecyl trimethyl ammonium bromide, tetradecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium bromide, octadecyl trimethyl ammonium bromide, polyethylene glycol or polyvinylpyrrolidone;

the solvent of the solution B is water;

the barium source compound in the solution B is barium chloride;

the solvent of the solution C is water;

the alkaline substance in the solution C is one of ammonium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate or sodium bicarbonate.

The invention also provides a manufacturing method of the barium titanate, which is to fire the obtained barium titanyl oxalate, continuously introduce oxygen into a box-type furnace, fire at 810-950 ℃ for 4H, and obtain the barium titanate.

Preferably, the barium titanate has a specific surface area of 10 to 15m ² And/g, c/a is 1.008-1.01.

Preferably, the barium titanate has a particle size distribution of 700nm or less.

Compared with the prior art, the technical scheme provided by the invention has the following technical effects:

according to the invention, the titanium compound and the oxalic acid radical compound are dissolved in an organic solvent, and meanwhile, the surfactant is added into the solution A to obtain the solution A, so that the solution A has stable properties, and after the solution A and the solution B are mixed, the growth of crystal grains is inhibited through the space blocking effect of the surfactant and an alkaline solution, and the superfine particle size barium titanyl oxalate is obtained. When this barium titanyl oxalate is sintered, highly crystalline barium titanate can be obtained at a relatively low temperature. The obtained barium titanate has a particle size distribution of 700nm or less, and the improved oxalate method provides a process for producing barium titanyl oxalate which is a barium titanate having a small particle size distribution and a high crystallinity, and which can be industrially mass-produced.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is an SEM picture of barium titanate of the present invention;

fig. 2 is an SEM picture of barium titanate of the present invention;

figure 3 is an XRD pattern of the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the scope of the present disclosure, since any structural modifications, proportional changes, or dimensional adjustments made by those skilled in the art should not be made in the present disclosure without affecting the efficacy or achievement of the present disclosure.

Examples

Referring to fig. 1 to 3, the present invention provides a technical solution: the preparation process of alkali catalyzed superfine barium titanyl oxalate includes the following steps:

s1, selecting raw materials; the raw materials are solution A, solution B and solution C; the solution A is a solution containing a titanium source compound, an oxalate compound and a surfactant; adding the solution A into a reaction vessel, and then, while stirring the solution A in the reaction vessel, supplying the solution B into the solution A and mixing the solutions, thereby performing a formation reaction of barium titanyl oxalate in the reaction vessel;

the solution A is an organic solvent; as an organic solvent, under the common mechanism of base catalysis and oxalate coprecipitation, the organic solvent is more favorable for the independent growth of crystal nucleus, and the solvent of the solution A is one of methanol, ethanol, butanol or glycol;

the titanium source compound in the solution A is one of titanium trichloride or titanium tetrachloride, the concentration of titanium ions in the solution A is not limited, and the concentration of titanium ions is preferably 0.1-5 mol/L, particularly preferably 0.1-1 mol/L, preferably titanium trichloride, particularly preferably titanium tetrachloride;

the oxalic acid radical compound is one of oxalic acid, ammonium oxalate, sodium oxalate or potassium oxalate, oxalic acid radical ions in the solution A are not limited, the concentration of the oxalic acid radical ions is preferably 0.3-4 mol/L, particularly preferably 0.3-2 mol/L, ammonium oxalate is preferred, and oxalic acid is particularly preferred;

the surfactant is one of dodecyltrimethylammonium bromide, tetradecyltrimethylammonium bromide, hexadecyltrimethylammonium bromide, octadecyltrimethylammonium bromide, polyethylene glycol (molecular weight 300, 5000, 7000, 10000) or polyvinylpyrrolidone, and the concentration of the surfactant is not limited, preferably 0.01 to 0.06mol/L, particularly preferably 0.01 to 0.03mol/L, preferably hexadecyltrimethylammonium bromide, polyethylene glycol of 300 molecular weight, particularly preferably hexadecyltrimethylammonium bromide;

the solution B is a solution containing a barium source compound; the concentration of barium ions in the solution B is not limited, but the concentration of barium ions is preferably 0.15 to 4mol/L, particularly preferably 0.15 to 2mol/L;

the solvent of the solution B is water;

the barium source compound in the solution B is barium chloride, and particularly preferably barium chloride is used as a barium source;

the solution C is an alkaline compound solution; the solvent of the solution C is water;

the alkaline substance in the solution C is one of ammonium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate and sodium bicarbonate, and the content of hydroxide ions in the solution C is not limited, and is preferably 0.000018 to 0.00008mol/L, particularly preferably 0.000018 to 0.0004mol/L, and particularly preferably ammonium hydroxide.

S2, mixing raw materials; adding the solution A into a reactor, stirring the solution A, adding the solution B into the solution A, wherein the required time for uniform mixing is 1-2H, and the time from the beginning to the end of the mixing of the solution B into the solution A is 1-2H, preferably 1H when the solution A is mixed in a reaction container with the solution B. The time from the start to the end of the mixing of the solution B to the solution A is within the above range, and barium titanyl oxalate is obtained.

S3, curing reaction; the time for the aging reaction is 4 to 8H, and the reaction temperature is at a temperature of 40 ℃ or lower when the liquid B is mixed with the liquid A, that is, the temperature of the liquid B and the liquid A in the reaction vessel when the liquid B is added to the reaction vessel is preferably 40 ℃ or lower, particularly preferably 20 to 35 ℃, and the liquid B is mixed with the liquid A, and then the reaction solution is aged for a predetermined time at a predetermined temperature. In the case of curing, the curing temperature is preferably 40℃or less, particularly preferably 20 to 35 ℃; the aging time is preferably 4 to 40 hours, particularly preferably 4 to 8 hours, and the addition of the liquid C to the mixed solution of the liquid A and the liquid B is preferably performed while stirring the liquid A when the liquid B is added to the liquid A and mixed. In the case where the entire amount of the liquid B is added to the liquid a and the mixture of the liquid B and the liquid a is completed and then the mixture is cured, the reaction liquid is preferably cured while stirring. The stirring speed is not particularly limited, but is preferably 150 to 300rpm, particularly preferably 200rpm.

S4, adding a solution; after completion of the reaction and aging, the solution C is added to the reaction solution while stirring, and the time for adding the solution C is preferably 0.5 to 2H, particularly preferably 0.5H. The reaction pH is adjusted to 1 to 8, preferably 2 to 7, particularly preferably 4 to 5. Then curing for 1-2H, wherein the curing temperature is preferably below 40 ℃, particularly preferably 20-35 ℃; the curing time is preferably 1 to 2 hours, particularly preferably 1 hour.

S5, regulating the pH; adding the solution C until the pH value of the mixed solution is 5-6; after the completion of the pH adjustment by the liquid C and the completion of the aging, the solid-liquid separation of the reaction liquid is performed by a usual method (sedimentation, filtration, centrifugation, etc.), and then the solid portion is washed with water. The method of washing with water is not particularly limited, but it is necessary to wash the concentration of chloride ions in the clear liquid to 100ppm or less, and then perform the test by titration. After completion of the water washing, alcohol washing is performed, and the alcohol washing is not particularly limited. After washing, the solid is dried and crushed as required to obtain barium titanyl oxalate.

S6, carrying out solid-liquid separation to obtain powder, wherein the powder is barium titanyl oxalate, the average particle size of the barium titanyl oxalate is 10-600 nm, preferably 50-400 nm, particularly preferably 50-300 nm, and the molar ratio of Ba/Ti is 0.998-1.003, preferably 1.001.

The barium titanyl oxalate obtained by the method of the present invention is barium titanyl oxalate in which barium titanate is produced at a temperature ranging from 810 to 950 ℃, preferably from 820 to 900 ℃, and particularly preferably from 820 to 850 ℃. The sintering time is preferably 3 to 10H, particularly preferably 4H.

The invention relates to a method for preparing barium titanate, which comprises the steps of firing the obtained barium titanyl oxalate, continuously introducing oxygen into a box-type furnace, wherein the firing temperature is 810-950 ℃ and the firing time is 4H, obtaining barium titanate, and sintering the barium titanate at 810-950 ℃ for 4H, thereby generating the barium titanate with the specific surface area of 10-15 m ² Barium titanate having a particle size distribution of 1.008 to 1.01 and a c/a of 700nm or less. Preferably 820 to 900℃and particularly preferably 820 to 850 ℃. Thus, barium titanate can be produced at a temperature ranging from 810 to 950 ℃, preferably from 820 to 900 ℃, particularly preferably from 820 to 850 ℃, and the barium titanate can produce a specific surface area ranging from 10 to 15m ² And/g, c/a is 1.008-1.01, and the barium titanate has a particle size distribution of 700nm or less, which can obtain barium titanate having a very high degree of crystallization and a narrow particle size distribution at a lower temperature than the prior art. Meanwhile, the tetragonal barium titanate with extremely high c/a shows extremely high purity, which is beneficial to the preparation of the subsequent ceramic capacitor.

After the sintering treatment, barium titanate having a very high c/a particle size distribution was obtained, and 200 particles were arbitrarily measured by a scanning electron microscope, and the average value was used as the average particle size.

In the present invention, it is necessary to obtain the target barium titanate by thermally decomposing barium titanyl oxalate by firing and to sufficiently remove the organic matter derived from oxalic acid. Regarding the firing conditions, the firing temperature is preferably 600 to 1200 ℃, more preferably 620 to 1100 ℃. At firing temperatures below 600 ℃, only a portion of the barium titanate is produced, or barium titanate of a single phase is not readily available. On the other hand, when the firing temperature exceeds 1200 ℃, the variation in particle size becomes large. The firing time is preferably 0.5 to 30 hours, more preferably 1 to 20 hours. The firing atmosphere is not particularly limited, and may be an inert gas atmosphere, a vacuum atmosphere, an acid gas atmosphere, or the atmosphere, or may be fired in the above-described atmosphere while introducing steam;

firing may be performed several times as needed. In order to make the powder characteristics uniform, the product after the primary firing can be crushed and then fired;

after firing, the mixture is cooled appropriately and pulverized as necessary to obtain barium titanate powder. The pulverization, if necessary, is suitably performed when the barium titanate obtained by firing is brittle and in the form of a lump, and the particles themselves of the barium titanate have the following specific average particle diameter and BET specific surface area. The barium titanate powder obtained as described above preferably has an average particle diameter of 0.5 μm or less, more preferably 0.02 μm as determined by Scanning Electron Microscope (SEM)About 0.5 μm. BET specific surface area is preferably 2 to 100m ² Preferably 2.5 to 50m ² And/g. In addition, regarding the composition of barium titanate obtained by the production method of the present invention, the molar ratio of Ba to Ti (Ba/Ti) is preferably 0.998 to 1.004, particularly preferably 0.999 to 1.003. In addition, the specific surface area of barium titanate is 15m ² When the ratio of the c-axis to the a-axis, which is an index of crystallinity, is within a range of not less than/g, the c-axis to a-axis ratio is preferably within a range of 1.0030 to 1.0055, and particularly preferably within a range of 1.0035 to 1.0050. When the firing temperature becomes high, grain growth occurs, and thus the specific surface area becomes less than 15m ² The c-axis/a-axis ratio in the range of/g is preferably larger than 1.0055, more preferably 1.0070 or more, particularly preferably 1.0075 or more.

In the barium titanate obtained by the method for producing barium titanate of the present invention, if necessary, a compound containing a subcomponent element may be added to the barium titanate obtained by the method for producing barium titanate of the present invention so as to contain a subcomponent element in order to adjust dielectric characteristics and temperature characteristics. Examples of usable compounds containing subcomponent elements include compounds containing at least 1 element selected from the group consisting of Sc, Y, la, ce, pr, nd, pm, sm, eu, gd, tb, dy, ho, er, tm, yb, lu rare earth elements, ba, li, bi, zn, mn, al, si, ca, sr, co, ni, cr, fe, mg, ti, V, nb, mo, W and Sn.

The subcomponent element-containing compound may be any of an inorganic substance and an organic substance, and examples thereof include oxides, hydroxides, chlorides, nitrates, oxalates, carboxylates, alkoxides, and the like containing the above elements, and when the subcomponent element-containing compound is a Si element-containing compound, silica sol, sodium silicate, and the like may be used in addition to the oxides and the like. The compound containing subcomponent elements may be used in 1 kind, or in 2 or more kinds in combination as appropriate. The combination of the amount and the compound added may be carried out according to a usual method.

The barium titanate may contain subcomponent elements, for example, by uniformly mixing barium titanate and a compound containing subcomponent elements, and then firing the mixture. The firing may be performed after uniformly mixing barium titanyl oxalate and a compound containing an accessory element;

in the case of manufacturing a monolithic ceramic capacitor using barium titanate obtained by the method for manufacturing barium titanate of the present invention, for example, first, barium titanate powder is mixed and dispersed in an appropriate solvent together with a compounding agent such as a conventionally known additive including subcomponent elements, an organic binder, a plasticizer, and a dispersing agent, and slurried, and sheet molding is performed. Thus, a ceramic sheet for manufacturing a multilayer ceramic capacitor was obtained. In manufacturing a multilayer ceramic capacitor from the ceramic sheet, first, a conductive paste for forming internal electrodes is printed on one surface of the ceramic sheet. After drying, a plurality of the ceramic sheets are laminated and pressure-bonded in the thickness direction, thereby forming a laminate. Then, the laminate is subjected to a heat treatment, a binder removal treatment, and firing to obtain a fired body. Then, ni paste, ag paste, nickel alloy paste, copper alloy paste, or the like is applied to the fired body and baked, thereby obtaining a multilayer ceramic capacitor.

The barium titanate powder obtained by the method for producing barium titanate of the present invention can be used as a material for a printed wiring board, a multilayer printed wiring board, or the like by mixing the barium titanate powder with a resin such as an epoxy resin, a polyester resin, or a polyimide resin to form a resin sheet, a resin film, an adhesive, or the like, or as a common material for suppressing a difference in shrinkage between an internal electrode and a dielectric layer, an electrode ceramic circuit board, a glass ceramic circuit board, a circuit peripheral material, or a dielectric material for an inorganic EL;

the barium titanate obtained by the method for producing barium titanate of the present invention is suitable as a catalyst used in reactions such as removal of exhaust gas and chemical synthesis, and a surface modifying material for a printing toner which imparts antistatic and cleaning effects.

30g of titanium tetrachloride, 75g of oxalic acid dihydrate and 10g of cetyltrimethylammonium bromide were dissolved in 545g of absolute ethanol to prepare 545g of a solution (solution A) containing titanium, oxalic acid and cetyltrimethylammonium bromide components, the concentration of titanium ions being 0.21mol/L and the concentration of oxalic acid being 0.78 mol/L. Further, 50g of barium chloride was dissolved in 85g of deionized water to prepare 85ml of a solution (solution B) containing a barium component at a concentration of 0.27 mol/L. 800ml of 28-concentration ammonia water is measured to obtain 800ml of alkaline solution (C solution);

the stirring was started throughout the course and the stirring rate was 200rpm. Next, the solution B was added dropwise at a constant speed while stirring the solution a, ensuring that the addition of the solution B was completed within one hour. And then curing the 5H, and after curing the 5H is completed. The C solution was added to the reaction solution at a constant rate, and it was necessary to complete the addition of the C solution within 0.5H. And curing for 1H again, and carrying out solid-liquid separation to obtain a precipitate. Washing with water and then alcohol. After the washing is completed, drying is performed. Obtaining barium titanyl oxalate;

the obtained barium titanyl oxalate was subjected to 4H firing at 850 ℃ to obtain barium titanate, fig. 1 is an SEM picture of this example, and fig. 3 is an XRD image of this example.

Example 2

This embodiment differs from embodiment 1 in that:

the barium titanyl oxalate thus obtained was subjected to 4H firing at 875 ℃.

Example 3

This embodiment is different from embodiment 1 and embodiment 2 in that:

the barium titanyl oxalate obtained was subjected to 4H firing at 900 ℃.

Example 4

This embodiment is different from embodiment 1, embodiment 2 and embodiment 3 in that:

the barium titanyl oxalate obtained was fired at 950℃for 4H to obtain barium titanate.

Comparative example 1

the stirring was started throughout the course and the stirring rate was 200rpm. Next, the solution B was added dropwise at a constant speed while stirring the solution a, ensuring that the addition of the solution B was completed within one hour. And then curing the 5H, and after curing the 5H is completed. And (5) performing solid-liquid separation to obtain a precipitate. Washing with water and then alcohol. After the washing is completed, drying is performed. Obtaining barium titanyl oxalate;

the barium titanyl oxalate obtained was subjected to 4H firing at 850 ℃.

Comparative example 2

The present comparative example is different from comparative example 1 in that:

the barium titanyl oxalate thus obtained was subjected to 4H firing at 875 ℃.

Comparative example 3

This comparative example differs from comparative example 1 and comparative example 2 in that:

the barium titanyl oxalate obtained was subjected to 4H firing at 900 ℃.

Comparative example 4

This comparative example differs from comparative example 1, comparative example 2 and comparative example 3 in that:

The physical property value data of barium titanate obtained in example 1, example 2, example 3, example 4, comparative example 1, comparative example 2, comparative example 3 and comparative example 4 are summarized as follows:

from the above data, it is understood that the barium titanate obtained by alkali catalysis in examples is extremely fine in particles and extremely high in crystallinity, compared with the barium titanate obtained in comparative examples, by comparison and judgment of the average particle diameter, BET specific surface area and c/a value at the time of firing at the same temperature.

Thus, embodiments of the present invention have been described in detail with reference to the accompanying drawings. It should be noted that, in the drawings or the text of the specification, implementations not shown or described are all forms known to those of ordinary skill in the art, and not described in detail. Furthermore, the above definitions of the components are not limited to the specific structures, shapes or modes mentioned in the embodiments, and may be simply modified or replaced by those of ordinary skill in the art.

Those skilled in the art will appreciate that the features recited in the various embodiments of the invention and/or in the claims may be combined in various combinations and/or combinations, even if such combinations or combinations are not explicitly recited in the invention. In particular, the features recited in the various embodiments of the invention and/or in the claims can be combined in various combinations and/or combinations without departing from the spirit and teachings of the invention. All such combinations and/or combinations fall within the scope of the invention.

The foregoing description of the embodiments has been provided for the purpose of illustrating the general principles of the invention, and is not meant to limit the invention thereto, but to limit the invention thereto, and any modifications, equivalents, improvements and equivalents thereof may be made without departing from the spirit and principles of the invention.

Claims

1. A method for preparing alkali-catalyzed superfine barium titanyl oxalate is characterized in that: the method comprises the following steps:

s1, selecting raw materials;

s2, mixing raw materials;

s3, curing reaction;

s4, adding a solution;

s5, regulating the pH;

s6, carrying out solid-liquid separation to obtain powder.

2. The method for manufacturing the alkali-catalyzed ultrafine barium titanyl oxalate according to claim 1, which is characterized in that: in S1, the raw materials are solution A, solution B and solution C;

the solution B is a solution containing a barium source compound;

the solution C is an alkaline compound solution.

3. The method for manufacturing the alkali-catalyzed ultrafine barium titanyl oxalate according to claim 2, which is characterized in that: in S2, adding the solution A into the reactor, stirring the solution A, and adding the solution B into the solution A, wherein the time required for uniform mixing is 1-2H.

4. The method for manufacturing the alkali-catalyzed ultrafine barium titanyl oxalate according to claim 3, wherein the method comprises the following steps: in S3, the curing reaction time is 4-8H, and the reaction temperature is below 40 ℃.

5. The method for manufacturing the alkali-catalyzed ultrafine barium titanyl oxalate according to claim 4, wherein the method comprises the following steps: in S4, the solution C is added to the mixed solution of the solution a and the solution B.

6. The method for manufacturing the alkali-catalyzed ultrafine barium titanyl oxalate according to claim 5, wherein the method comprises the following steps: in S5, adding the C solution until the pH value of the mixed solution is 5-6; the powder obtained by solid-liquid separation is barium titanyl oxalate.

7. The method for manufacturing the alkali-catalyzed ultrafine barium titanyl oxalate according to claim 2, which is characterized in that: the solution A is an organic solvent;

the solvent of the solution A is one of methanol, ethanol, butanol or glycol;

the solvent of the solution B is water;

the barium source compound in the solution B is barium chloride;

the solvent of the solution C is water;

8. A method for producing barium titanate by the method for producing alkali-catalyzed ultrafine barium titanyl oxalate according to any one of claims 1 to 7, characterized in that: and (3) firing the obtained barium titanyl oxalate, continuously introducing oxygen into a box-type furnace, wherein the firing temperature is 810-950 ℃ and the firing time is 4H, and thus obtaining the barium titanate.

9. The method for producing barium titanate according to claim 8, wherein: the barium titanate can generate the barium titanate with the specific surface area of 10-15 m ² Per gram, c/a is 1.008-1.01Barium titanate.

10. The method of producing barium titanate according to claim 9, wherein: the particle size distribution of the barium titanate is below 700 nm.