KR20080070981A - A method of preparing barium-titanate powder by oxalate process and barium-titanate powder prepared by the same - Google Patents

Abstract

A method for preparing barium titanate powder is provided to produce the barium titanate powder having a uniform particle size distribution and improved crystallinity. A method for preparing barium titanate powder includes the steps of: (S10) providing an aqueous barium chloride solution and an aqueous titanium tetrachloride solution having concentrations of 0.2-2.0 mol/L, respectively; (S20) producing barium titanyl oxalate[BaTiO(C2O4)2.4H2O] crystals by adding the aqueous solutions to an aqueous oxalic acid solution having a concentration of 0.2-5.0 mol/L so as to provide a barium chloride/titanium tetrachloride molar ratio of 1-1.5; (S40) wet-milling the barium titanyl oxalate crystals; (S50) drying the wet-milled barium titanyl oxalate crystals; (S60) subjecting the dried barium titanyl oxalate crystals to the first heat treatment to produce barium titanate crystals; and (S80) heat-treating the barium titanate crystals at the first heat treatment temperature or below. Further, the barium chloride and the titanium tetrachloride are sprayed by a spray nozzle.

Description

A method of preparing Barium-Titanate powder by Oxalate Process and Barium-Titanate powder prepared by the same}

1 is a flowchart for explaining step by step a method for producing barium titanate powder according to an embodiment of the present invention.

The present invention relates to a method for producing barium titanate powder and a barium titanate powder prepared by the method, and more particularly, to a method for producing barium titanate powder by an oxalate process having a uniform particle size distribution and improved crystallinity. It relates to a barium titanate powder produced by the method.

Conventional barium titanate powder was prepared by a solid phase reaction in which titanium dioxide (TiO ₂ ) and barium carbonate (BaCO ₃ ) were mixed and heat-treated at a high temperature. High purity / composition uniformity, fine grain / particle uniformity, non-aggregation / high dispersion, etc. are required according to high dielectric constant composition, dielectric thinning and high lamination), low temperature baking, high frequency It is manufactured by the synthesis method. In particular, as the multilayer ceramic capacitor becomes thin and highly laminated, there is a demand for barium titanate powder having a uniform particle size distribution and high crystallinity even under 300 nm.

As a prior art for manufacturing such barium titanate powder, there is a "method of preparing fine powdered barium titanate" of Korean Patent Application No. 2002-0051799. The method presented here is a solid phase reaction method that can produce fine powder at a low temperature at a relatively low price. In order to perform this method, there is a problem in that the yield of barium carbonate is lengthened and the production yield is reduced. In order to solve this problem, when the raw material of barium carbonate is used as a raw material, the increase in raw material price not only increases the overall manufacturing cost but also fundamental limitations of the solid phase reaction method such as low purity, composition nonuniformity, and particle size nonuniformity. Another problem arises that it cannot be overcome.

An object of the present invention is to provide a method for producing barium titanate powder having improved particle size uniformity and a barium titanate powder prepared by the method.

Still another object of the present invention is to provide a method for preparing barium titanate powder having improved crystallinity and a barium titanate powder prepared by the method.

According to the invention,

(a) preparing an aqueous solution of barium chloride (BaCl ₂ ) and an aqueous solution of titanium tetrachloride (TiCl ₄ ) having a molar ratio (barium chloride / titanium tetrachloride) of 1 to 1.5;

(b) Barium titanyl oxalate [BaTiO (C ₂ O ₄ ) ₂ ㆍ 4H ₂ O] crystals by spraying the aqueous solution and dropwise addition to an aqueous solution of oxalic acid (H ₂ C ₂ O ₄ ) having a concentration of 0.2 ~ 5.0 mol / l Generating a;

(c) wet grinding the barium titanyl oxalate crystals;

(d) drying the wet milled barium titanyl oxalate crystals;

(e) first heat treating the dried barium titanyl oxalate crystal to produce barium titanate crystal; And

(f) subjecting the barium titanate crystal produced by the first heat treatment to a second heat treatment at a temperature below the first heat treatment temperature; a method for producing barium titanate powder is provided.

According to one embodiment of the present invention, the concentrations of the barium chloride solution and the titanium tetrachloride solution are 0.2 to 2.0 mol / l, respectively.

According to another embodiment of the present invention, between the step (b) and (c), the step of maturing the produced barium titanyl oxalate crystals, filtering the aged barium titanyl oxalate crystals, And washing the filtered barium titanyl oxalate crystal with excess water.

According to another embodiment of the present invention, the wet grinding of step (c) is performed by adding a nitrogen-containing additive selected from ammonia, amines, ammonium compounds, and amino acids.

According to another embodiment of the present invention, the drying of the step (d) is carried out at a temperature of 400 ° C. or lower as a temperature higher than the boiling point of the solvent used for the wet grinding of the step (c).

According to another embodiment of the present invention, the first heat treatment of step (e) is carried out at a temperature of 800 ~ 1000 ℃ range.

According to another embodiment of the present invention, the temperature increase rate from the drying temperature of the step (d) to the first heat treatment temperature of the step (e) is 0.5 ~ 10 ℃ / min.

According to still another embodiment of the present invention, the method may further include pulverizing the barium titanate crystal produced by the first heat treatment between the first heat treatment in the step (e) and the second heat treatment in the step (f).

According to another embodiment of the present invention, the method may further include adding barium carbonate (BaCO ₃ ) between the first heat treatment of step (e) and the second heat treatment of step (f).

According to another embodiment of the present invention, the secondary heat treatment of step (f) is performed at a temperature in the range of 600 ~ 1000 ℃.

According to another embodiment of the present invention, the temperature increase rate to the second heat treatment temperature of the step (f) after the first heat treatment of the step (e) is 0.5 ~ 10 ℃ / min.

According to another embodiment of the present invention, the method further comprises the step of pulverizing the barium titanyl oxalate crystals subjected to the second heat treatment in the step (f).

In addition, according to the present invention,

A barium titanate powder prepared by the method of any one of the above embodiments is provided.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a flowchart for explaining step by step a method for producing barium titanate powder according to an embodiment of the present invention.

Hereinafter, a method of manufacturing barium titanate powder according to an embodiment of the present invention will be described with reference to FIG. 1.

First, an aqueous solution of barium chloride (BaCl ₂ ) and an aqueous solution of titanium tetrachloride (TiCl ₄ ) are prepared (S10). Aqueous solution of barium chloride is usually used by dissolving BaCl ₂ · 2H ₂ O in water, and the preferred concentration range is 0.2 to 2.0 mol / l. When the concentration of the barium chloride solution is less than 0.2 mol / l, the productivity of the barium titanate to be described later compared to the volume of the barium chloride solution is not preferable, and when the concentration exceeds 2.0 mol / l solubility of barium chloride in water It is not preferable because there is a possibility of precipitation of barium chloride out of range. Titanium tetrachloride aqueous solution is usually used by diluting a high concentration of titanium tetrachloride solution, the preferred concentration range is 0.2 ~ 2.0 mol / l. If the concentration of the aqueous titanium tetrachloride solution is less than 0.2 mol / l is not preferable because the productivity of the barium titanate relative to the volume of the aqueous titanium tetrachloride solution is not preferable, the solubility range of titanium tetrachloride in water when the concentration is above 2.0 mol / l. Titanium tetrachloride is likely to precipitate out of the range, which is undesirable. The barium chloride aqueous solution and the titanium tetrachloride aqueous solution are preferably mixed at a ratio of 1 to 1.5 on a molar ratio (barium chloride / titanium tetrachloride), and more preferably at a ratio of 1 to 1.1. If the molar ratio is less than 1, the molar ratio of barium titanate, which is the final product, is very unlikely to be lowered to less than 1, and is not preferable. If the molar ratio is more than 1.5, a second phase (other phase other than barium titanate, Ba ₂ TiO ₉ ) is produced for example, which is undesirable. When the molar ratio of the barium titanate, which is the final product, is lowered to less than 1, abnormal production and abnormal grain growth are caused, which is not preferable.

Next, a mixed aqueous solution of the aqueous barium chloride solution and titanium tetrachloride solution or each of these aqueous solutions is added dropwise to the aqueous solution of oxalic acid (H ₂ C ₂ O ₄ ) using a high-speed jet nozzle to produce barium titanyl oxalate [BaTiO (C ₂ O). ₄ ) ₂ ㆍ 4H ₂ O] crystals are generated (S20). At this time, the oxalic acid aqueous solution is preferably used in an amount larger than the barium chloride aqueous solution or titanium tetrachloride aqueous solution. The preferred concentration range of the oxalic acid aqueous solution is 0.2 to 5.0 mol / l. When the concentration of the aqueous solution of oxalic acid is less than 0.2 mol / l, the productivity of barium titanate is not preferable as compared to the volume of the aqueous solution of oxalic acid. It is not desirable. In this case, the temperature of the oxalic acid aqueous solution is preferably maintained at 20 to 100 ° C, more preferably at 50 to 90 ° C. It is preferable that the time for dropping the barium chloride solution and the titanium tetrachloride solution in the form of a mixed solution or separately by nozzle spraying to the oxalic acid solution separately is 1 to 3 hours. This dropping time can be achieved by adjusting the injection speed of the nozzle. The injection nozzle may use a hydraulic or two-fluid nozzle depending on the flow of the fluid, it is more advantageous to use a hydraulic nozzle in terms of convenience or to obtain a uniform precipitate. As the hydraulic nozzle, a full cone, a hollow cone, a flat, or the like may be used. As such, a process of generating barium titanyl oxalate crystal by adding a mixed solution containing barium (Ba) and titanium (Ti) ions to oxalic acid may be represented as in Scheme 1 below.

Scheme 1

BaCl ₂ 2H ₂ O + TiOCl ₂ + 2H ₂ C ₂ O ₄ ㆍ 2H ₂ O → BaTiO (C ₂ O ₄ ) ₂ ㆍ 4H ₂ O + 4HCl

Next, the produced barium titanyl oxalate crystals are aged, filtered, and washed with water (S30). It is advantageous in terms of productivity that the aging time is performed for 0.5 to 2 hours. Here, the filtration refers to a process of specifically filtering barium titanyl oxalate in the form of a slurry using a centrifuge. Thereafter, the filtered barium titanyl oxalate is washed with excess water until the pH of the washing liquid is neutral.

Is preferably. If the content is less than 0.5 mole parts, such as acidification and high viscosity of the slurry after pulverization, such as phenomena, and when it exceeds 20 mole parts, the titanium component is released and the barium / titanium molar ratio is unbalanced.

Next, the wet milled barium titanyl oxalate is dried at a temperature of 400 ° C. or less to remove the used solvent (S50). In this case, in order to evaporate and remove the solvent used, it is natural that the drying temperature should be above the boiling point of the solvent.

Next, the dried barium titanyl oxalate crystal is first heat-treated (S60). Primary heat treatment is carried out at a temperature in the range from 800 to 1000 ° C. When the heat treatment temperature is less than 800 ° C., barium titanate is hardly formed and is not preferable. When the heat treatment temperature is higher than 1000 ° C., the particle size of the barium titanate powder formed is too large, which is not preferable. The temperature increase rate from the drying temperature to the primary heat treatment temperature is preferably 0.5 to 10 ° C / min, more preferably 1 to 5 ° C / min. When the temperature increase rate is less than 0.5 ℃ / min is not preferable because the productivity of barium titanate is lowered, when the temperature exceeds 10 ℃ / min is not preferable because the temperature distribution is not uniform and the particle size of the barium titanate powder is uneven. By performing the first heat treatment as described above, barium titanate powder having a size of tens to hundreds of nm is removed by performing the same process as in Schemes 2 to 3 by removing water and excess carbon dioxide present as crystallized water in barium titanyl oxalate. Get

Scheme 2

BaTiO (C ₂ O ₄ ) ₂ ㆍ 4H ₂ O → BaTiO (C ₂ O ₄ ) ₂ + 4H ₂ O

Scheme 3

BaTiO (C ₂ O ₄ ) ₂ + 1/2 O ₂ → BaCO ₃ + TiO ₂ + 2CO ₂

Scheme 4

BaCO ₃ + TiO ₂ → BaTiO ₃

Thereafter, it is preferable to grind the barium titanate crystal generated through the first heat treatment process (S70), but the grinding process may be omitted. In this case, grinding may be performed by wet grinding using a mill such as a beads mill, an attention mill, and a ball mill with a predetermined solvent, a jet mill and a disk mill ( Such as a disk mill, dry grinding using a collision between raw materials or friction with a grinder without using a solvent. In this case, the pulverization is for eliminating the intergranulation of the barium titanate powder. After the wet pulverization, a drying step is further required, but it is not necessary to use a specially limited facility for drying. In case of using the equipment with high crushing efficiency in this stage of crushing process, it is possible to break the particles and generate a large amount of fine powder, which may lower the particle size distribution and crystallinity. Lowering it is desirable to break only the necking of the particles without breaking the particles themselves.

In addition, although it is preferable to further add barium carbonate (BaCO ₃ ) to the barium titanate crystal produced through the first heat treatment (S70), the addition process of the barium carbonate may be omitted. The barium carbonate addition process may be performed in parallel with the barium titanate grinding process, or may be performed alone without the grinding process. Hereinafter, the case where the barium carbonate addition process is performed in parallel with the grinding process will be described. First, the molar ratio of barium / titanium (Ba / Ti) in barium titanate is measured by using an analyzer such as XRF, and then an appropriate amount of barium carbonate (BaCO ₃ ) is added to barium titanate according to the molar ratio to grind. For example, when the barium / titanium molar ratio is in the range of 0.997 to 0.999, barium carbonate is added in the range of 0.08 to 2.28 parts by weight relative to 100 parts by weight of barium titanate, and when the molar ratio is in the range of 0.999 to 1.001, the amount of barium carbonate is 0.08 to 1.5. It is added in the sub range, and the barium carbonate is added in the range of 0.08 to 0.76 parts by weight when the molar ratio is in the range of 1.001 to 1.103.

 Accordingly, grain growth is suppressed in the subsequent secondary heat treatment, so that the barium titanate powder may have a more uniform particle size distribution and maintain a constant barium / titanium molar ratio. However, if the barium / titanium molar ratio of barium titanate after the first heat treatment is within a desired range, it is not necessary to add additional barium carbonate, and further grinding is not necessary unless the bonding effect between the particles of barium titanate powder becomes noticeable.

Next, the barium titanate crystal produced by the first heat treatment is subjected to a second heat treatment (S80). This secondary heat treatment process is performed at a temperature below the primary heat treatment temperature. That is, the secondary heat treatment is carried out at a temperature in the range of 600 ~ 1000 ℃. If the heat treatment temperature is less than 600 ° C., it is not preferable because there is little secondary heat treatment effect. If the heat treatment temperature is higher than 1000 ° C., the particle size of the barium titanate powder formed is too large, which is not preferable. It is preferable that it is 0.5-10 degrees C / min, and, as for the temperature increase rate to the secondary heat treatment temperature after the said 1st heat processing, it is more preferable that it is 1-5 degrees C / min. When the temperature increase rate is less than 0.5 ℃ / min is not preferable because the productivity of barium titanate is lowered, when the temperature exceeds 10 ℃ / min is not preferable because the temperature distribution is not uniform and the particle size of the barium titanate powder is uneven. By performing the secondary heat treatment in this manner, barium titanate powder having a uniform particle size distribution and high crystallinity can be obtained.

Finally, the barium titanate crystals subjected to the secondary heat treatment may be further ground, which may be omitted.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments, but the present invention is not limited thereto.

Examples 1-8

(Generation and aging of barium titanyl oxalate crystal)

1320 L of a 1 mol / L barium chloride solution and 1200 L of a 1 mol / L titanium tetrachloride solution were mixed well in a 4M ³ glass-lined reactor to form a mixed aqueous solution. Thereafter, the mixed aqueous solution was sprayed at a rate of 2.5 L / min using a full con type nozzle to 2520 L of an oxalic acid aqueous solution having a concentration of 1 mol / L prepared in a 6M ³ reactor. At this time, the oxalic acid solution was sprayed while stirring with a stirrer, the stirring speed of the stirrer was maintained at 150rpm, the temperature of the oxalic acid solution was maintained at 90 ℃.

 After the dropwise addition of the mixed aqueous solution for 2 hours, the reaction temperature was maintained for 1 hour, and then air-cooled with stirring to mature for 1 hour. As a result, barium titanyl oxalate crystals in a slurry state were obtained.

(Filtration and washing of the produced barium titanyl oxalate slurry)

The barium titanyl oxalate slurry prepared above was filtered through a centrifugal separator and washed with excess water to have a pH of 6 or more, thereby obtaining barium titanyl oxalate crystals.

(Wet grinding and drying of the produced barium titanyl oxalate crystals)

To 50 kg of the barium titanyl oxalate crystal, 250 kg of dehydrated ion and 0.5 kg of 29% by volume ammonia water (8.4 mole parts relative to 100 moles of barium titanyl oxalate) were added and the resulting slurry was stirred in a mixing bath. At this time, the pH of the slurry was 9.3. Thereafter, the barium titanyl oxalate crystals were wet pulverized with a horizontal beads mill of 20 L so that the maximum particle diameter was 5 um or less. After grinding, the slurry had a pH of 5.1 and a viscosity of 1800 cP. The barium titanyl oxalate slurry thus obtained was dried in an oven at a temperature of 200 ° C. for 12 hours, and then the chlorine ion content was measured. As a result, the chloride content was 200 ppm.

(Primary heat treatment)

The dried barium titanyl oxalate crystal was heat-treated in an electric furnace while varying the temperature for each example in a temperature range of 800 ° C to 1000 ° C. As a result, barium titanate crystals were obtained.

(Pulverization of Barium Titanium Crystal after First Heat Treatment)

After the first heat treatment, the barium titanate crystals were added with barium carbonate differentially for each example within a range of 0 to 0.5wt%, and grinding was performed for 100 minutes at a minimum rpm with a bead mill. After grinding, the slurry was dried in an oven at 150 ° C. for 24 hours.

(Secondary heat treatment)

The barium titanate crystals subjected to the pulverization after the first heat treatment were subjected to the second heat treatment while changing the temperature for each example in the temperature range of 600 to 1000 ° C.

(Evaluation of Crystallinity and Particle Size Distribution of Produced Barium Titanium Powder)

The results of evaluating the crystallinity and particle size distribution of the produced barium titanate powder are shown in Table 1 below. In Table 1, c / a and k-factors are indicators for evaluating the crystallinity of barium titanate using XRD. The larger these values, the better the crystallinity. The particle size of the barium titanate powder was expressed as a distribution of the measured size measured by using an image analysis program after taking a scanning electron microscope (SEM) picture.

[Table 1] Crystallinity and particle size distribution of barium titanate

Primary heat treatment Barium Carbonate Added Wet grinding Secondary heat treatment c / a K-factor Average particle size (nm) Particle size distribution Example 1 850 ℃ 0 wt% X 800 ℃ 1.008 3.11 179 Great Example 2 900 ℃ 0 wt% O 800 ℃ 1.008 2.32 192 Great Example 3 900 ℃ O.2 wt% O 800 ℃ 1.010 3.15 187 Very good Example 4 900 ℃ 0.3 wt% O 850 ℃ 1.010 3.60 172 Very good Example 5 900 ℃ 0.3 wt% O 900 ℃ 1.011 4.24 211 Great Example 6 950 ℃ O.2 wt% O 900 ℃ 1.011 3.83 253 Very good Example 7 950 ℃ 0.3 wt% X 900 ℃ 1.010 4.45 293 Great Example 8 950 ℃ O.5 wt% 0 950 ℃ 1.011 4.65 276 Very good

However, the particle size distribution is based on the average particle size, if the number of particles having a larger or smaller particle size is relatively large, 'bad', very small 'very good', small 'excellent', and medium 'normal' Marked as. Excellent particle size distribution means excellent particle size uniformity.

Comparative Examples 1 to 5

In Example 1 to 8, the process after the first heat treatment was omitted, and only the first heat treatment was performed as a comparative example. The heat treatment temperature of Comparative Examples 1-5 was 800 degreeC, 900 degreeC, or 1000 degreeC, respectively. Here, the results of evaluating the crystallinity and particle size distribution of the produced barium titanate powder are shown in Table 2 below.

[Table 2] Crystallinity and particle size distribution of barium titanate

Heat treatment temperature Secondary heat treatment temperature c / a K-factor Average particle size (nm) Particle size distribution Comparative Example 1 800 ℃ Do not process 1.000 - 119 Bad Comparative Example 2 800 ℃ 900 ℃ 1.010 2.28 209 Bad Comparative Example 3 900 ℃ Do not process 1.007 2.12 183 usually Comparative Example 4 900 ℃ 950 ℃ 1.009 3.84 378 Bad Comparative Example 5 1000 ℃ Do not process 1.009 3.78 396 usually

However, the values of c / a and K-factor are "-" when XRD analysis is observed as a cubic phase rather than a tetragonal phase, and thus the value cannot be measured. The particle size distribution is expressed as 'bad' if the number of particles having a larger or smaller particle size is relatively large based on the average particle size, 'very good' if very small, 'excellent' for small and medium 'normal'. . Excellent particle size distribution means excellent particle size uniformity.

Summarizing the above results, it can be seen that the second heat treatment below the first heat treatment temperature shows better results in terms of crystallinity, average particle size, and particle size distribution than after the first heat treatment. After the addition of barium carbonate and wet grinding, it was found that the second heat treatment was carried out below the first heat treatment temperature.

Although the present invention has been described with reference to the examples, these are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

According to the present invention, there can be provided a method for producing barium titanate powder having improved particle size uniformity and a barium titanate powder prepared by the method.

According to the present invention, there can be provided a method for producing barium titanate powder having improved crystallinity and a barium titanate powder prepared by the method.

Claims (14)

(a) preparing a barium chloride (BaCl ₂ ) aqueous solution and a titanium tetrachloride (TiCl ₄ ) aqueous solution each having a concentration of 0.2 to 2.0 mol / l; (b) barium titanyl oxalate by spraying the aqueous solution dropwise to an aqueous solution of oxalic acid (H ₂ C ₂ O ₄ ) having a concentration of 0.2 to 5.0 mol / l by spraying at a ratio of 1 to 1.5 for a barium chloride / titanium tetrachloride molar ratio Generating BaTiO (C ₂ O ₄ ) ₂ .4H ₂ O] crystals; (c) wet grinding the barium titanyl oxalate crystals; (d) drying the wet milled barium titanyl oxalate crystals; (e) first heat treating the dried barium titanyl oxalate crystal to produce barium titanate crystal; And and (f) subjecting the barium titanate crystal produced by the first heat treatment to a second heat treatment at a temperature not higher than the first heat treatment temperature. The method of claim 1, In the step (b), the barium chloride aqueous solution and titanium tetrachloride aqueous solution is a method of producing a barium titanate powder, characterized in that the mixture before the injection. The method of claim 1, In the step (b), the barium chloride aqueous solution and titanium tetrachloride aqueous solution is a method for producing barium titanate powder, characterized in that the mixing while being sprayed by a spray nozzle. The method of claim 1, Between steps (b) and (c), Aging the produced barium titanyl oxalate crystals; Filtering the aged barium titanyl oxalate crystals; And washing the filtered barium titanyl oxalate crystals with an excess amount of water. The method of claim 1, The wet grinding step (c) is a method for producing barium titanate powder, characterized in that the addition of a nitrogen-containing additive selected from ammonia, amines, ammonium compounds, and amino acids. The method of claim 1, The drying of step (d) is a method of producing barium titanate powder, characterized in that carried out at a temperature below 400 ℃ as a temperature higher than the boiling point of the solvent used in the wet grinding of step (c). The method of claim 1, The primary heat treatment of step (e) is a method for producing barium titanate powder, characterized in that carried out at a temperature in the range of 800 ~ 1000 ℃. The method of claim 1, Method for producing a barium titanate powder, characterized in that the temperature increase rate from the drying temperature of step (d) to the first heat treatment temperature of step (e) is 0.5 ~ 10 ℃ / min. The method of claim 1, And pulverizing the barium titanate crystals produced by the first heat treatment between the first heat treatment in step (e) and the second heat treatment in step (f). The method of claim 1, The method of manufacturing barium titanate powder further comprises the step of adding barium carbonate (BaCO ₃ ) between the first heat treatment of step (e) and the second heat treatment of step (f). The method of claim 1, The secondary heat treatment of step (f) is a method for producing barium titanate powder, characterized in that carried out at a temperature of 600 ~ 1000 ℃ range. The method of claim 1, Method of producing a barium titanate powder, characterized in that the temperature increase rate to the secondary heat treatment temperature of step (f) after the first heat treatment of step (e) is 0.5 ~ 10 ℃ / min. The method of claim 1, Method for producing a barium titanate powder, characterized in that further comprising the step of grinding the barium titanyl oxalate crystals subjected to the second heat treatment of step (f). Barium titanate powder produced by the method of any one of claims 1 to 13.

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