KR101935268B1 - Glass composition of cover coat enamel for glass lining - Google Patents

Abstract

The present invention relates to a glass composition for top glaze for glass lining and a manufacturing method thereof. According to the present invention, the glass composition for top glaze for glass lining comprises: 55-75 parts by weight of SiO_2; 10-20 parts by weight of R_2O (R represents Li, Na, and K); 1-10 parts by weight of R′O (R′ represents Mg, Ca, Sr and Ba); 8-18 parts by weight of ZrO_2; 0.5-5 parts by weight of Al_2O_3; and 0.5-2.5 parts by weight of CoO as main ingredients. According to the manufacturing method of the glass composition for top glaze, in order to achieve a target content amount of ZrO_2 based on composition of glass, excess of ZrO_2 may be added to be dissolved or 1-5 wt% of crystalline SiO_2 or ZrO_2 powder may be added to the dissolved glass as a filler based on the weight percent of the whole glass. The glass composition for top glaze for glass lining obtained by the abovementioned method can be effectively used in manufacturing a glass lining product having high-temperature properties, and extremely excellent chemical resistance such as acidic resistance, alkali resistance, etc.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a glass composition for a glass lining,

The present invention relates to a glass composition for top coat application for coating a glass lining apparatus based on a low carbon steel sheet or a stainless steel sheet with a glaze to withstand strict use conditions in chemical industry, pharmaceutical industry, food industry, More particularly, the present invention provides a glass composition for topical application which can produce a glass lining product having excellent chemical resistance such as high temperature characteristics, acid resistance and alkali resistance.

Conventional glass lining apparatuses are coated with a low glaze of 0.2 to 0.4 mm in order to strengthen the adhesion of the low-carbon steel or stainless steel plate to the base metal, and then the upper glaze having high corrosion resistance is coated with 0.8 to 2.0 mm . ≪ / RTI >

Here, the top glaze of the glass lining apparatus is required to have excellent chemical resistance, such as acid resistance and alkali resistance, due to its direct contact with a solution of severe conditions such as strong acid or strong alkali.

Japanese Patent No. 4,520,626 Japanese Patent Laid-Open No. 2005-060117

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems and to obtain a glass having high chemical resistance. The present invention provides a ZrO ₂ component having a ZrO ₂ content by a predetermined weight percentage by adding a certain amount of ZrO ₂ component, It is a second object of the present invention to provide a method for improving the chemical resistance by adding crystalline SiO ₂ or ZrO ₂ powder as a filler to the glass. The present invention aims to provide a top glaze which is improved in function so that the corrosion resistance of a glass lining device is higher under severe conditions such as strong acid or strong alkali.

The present invention provides an upper glass composition for glass lining having excellent chemical resistance such as acid resistance and alkali resistance in a harsh environment, and a method for producing the same.

The topical glass composition for the glass lining of the present invention comprises,

55 to 75 parts by weight of SiO ₂ ,

10 to 20 parts by weight of R ₂ O (wherein R represents Li, Na or K)

1 to 10 parts by weight of R'O (wherein R 'represents Mg, Ca, Sr or Ba)

ZrO ₂ 8 ~ 18 parts by weight,

0.5 to 5 parts by weight of Al ₂ O ₃ , and

0.5 to 2.5 parts by weight of CoO.

The glass composition for top coat for the glass lining may further comprise 1 to 5 parts by weight of crystalline SiO ₂ or ZrO ₂ powder as a filler.

A method of manufacturing an upper glaze for glass lining of the present invention comprises:

SiO _2, R ₂ O (where, R represents a Li, Na or K), R'O (where, R 'represents a Mg, Ca, Sr or Ba), ZrO _2, the Al ₂ O ₃ and CoO Mixing (S1) a glass raw material;

(S2) melting and vitrifying the glass raw material produced in the step S1;

Cooling and milling the melt produced in the step S2 (S3);

.

The method may further comprise the step of adding crystalline SiO ₂ or ZrO ₂ 1 to 5 parts by weight of the powder may be added.

Wherein the step S 1 is a step of mixing 55 to 75 parts by weight of SiO ₂ , 10 to 20 parts by weight of R ₂ O (where R represents Li, Na or K) and 1 to 10 parts by weight of R'O Ca, Sr, or Ba), 10.4 to 25.2 parts by weight of ZrO ₂ , 0.5 to 5 parts by weight of Al ₂ O ₃ , and 0.5 to 2.5 parts by weight of CoO to produce a glass raw material.

The step S2 may be a step of melting the glass raw material produced in the step S1 at 1,300 to 1,600 DEG C to vitrify it.

The step S3 may be a step of cooling the molten material into water followed by quenching, drying and pulverizing, or molding the molten material into a ribbon using a rotating water-cooled twin roller, and then pulverizing the ribbon.

The milling in the step S3 may be performed using a ball mill, a jet mill or a fine mill.

As described above, the top coat glaze for glass lining of the present invention is excellent in high temperature characteristics and exhibits excellent chemical resistance such as acid resistance and alkali resistance under severe conditions such as strong acid or strong alkali.

1 is a schematic view of ZrO ₂ precipitation during glass melting. 1 is a view schematically showing a glass 2 melted in the crucible 1 and a ZrO ₂ component (ZrO ₂ -rich glass) 3 precipitated in the lower part of the crucible 1.
2 and 3 are photographs and structural diagrams of the acid resistance measuring apparatus.
Figs. 2 and 3 are schematic views of actual photographs and apparatuses of an apparatus for measuring acid resistance of the present invention, respectively. In FIGS. 2 and 3, reference numeral 4 denotes a Liebig condenser, reference numeral 5 denotes a borosilicate glass specimen holder, and reference numeral 6 denotes a jacket heater.
Figs. 4, 5 and 6 are structural diagrams of a water bath apparatus photograph for measurement of alkali resistance, a photograph of apparatus for alkali resistance measurement, and an alkali resistance measurement apparatus, respectively, mounted on a rawter bath. In FIGS. 4 to 6, reference numeral 7 denotes a measurement specimen, reference numeral 8 denotes a stainless steel container, and reference numeral 9 denotes a sodium hydroxide solution.

In order to achieve the above-mentioned object, the present invention provides a glass composition for topical application comprising 55 to 75 parts by weight of SiO ₂ , 10 to 20 parts by weight of R ₂ O (R represents Li, Na, K) (R 'represents Mg, Ca, Sr and Ba), 8 to 18 parts by weight of ZrO ₂ , 0.5 to 5 parts by weight of Al ₂ O ₃ and 0.5 to 2.5 parts by weight of CoO as main components.

The top coat glaze for the glass lining of the present invention having the above composition is excellent in high temperature characteristics and exhibits excellent chemical resistance such as acid resistance and alkali resistance under severe conditions such as strong acid or strong alkali.

The specific gravity of the ZrO ₂ component in the glass composition is higher than the specific gravity of the glass (specific gravity of glass: about 2.5, specific gravity of ZrO ₂ : about 5.73), and precipitation of the ZrO ₂ component occurs during the glass melting process, To 18 parts by weight) of ZrO ₂ in the topical glaze.

Therefore, in the present invention, as a method of containing the ZrO ₂ component in the glass composition in a target amount, a method of adding 30 to 40% by weight as a percentage based on the ZrO ₂ content of the target glass composition at the preparation of the raw material batch can be used .

Further, in order to further improve the chemical resistance of the top glaze, crystalline SiO ₂ or ZrO ₂ The powder may be added as a filler in an amount of 1 to 5% by weight as a percentage based on the whole glass. The above two methods can be used selectively or in combination.

As a glaze for glass lining, it is first coated (top coat) after undercoating to improve adhesion with base metal, and because of the nature of the glass lining product, compressive stress must be applied to the top lining portion So that the coefficient of thermal expansion is usually smaller in the order of the base metal, the lower and upper surfaces, and the thermal expansion coefficient of the upper surface glaze becomes equal to or smaller than that of the lower glaze.

Therefore, it is preferable to use a glass having a linear expansion coefficient of 92 to 112 x 10 < ^-7 > / DEG C in the temperature range of 30 to 380 DEG C.

The reasons for limiting the content of each component in the present invention are as follows.

First, SiO ₂ is a main component required to constitute the skeleton of glass, and its content is 55 to 75 parts by weight, preferably 60 to 70 parts by weight. If the amount of SiO ₂ is more than 75 wt%, the thermal expansion coefficient becomes too low and the solubility tends to be low. If the amount of SiO ₂ is less than 55 parts by weight, the chemical durability is lowered and the coefficient of thermal expansion becomes too large.

Al ₂ O ₃ has a remarkable effect in improving the stability of the glass, and its content is from 0.5 to 5 parts by weight, preferably from 1.5 to 3 parts by weight. When the amount of Al ₂ O ₃ is more than 5 parts by weight, it is difficult to dissolve the glass. When the amount of Al ₂ O ₃ is less than 0.5 parts by weight, the glass is liable to fail and the production of stable glass becomes difficult.

The alkali metal oxides Li ₂ O, Na ₂ O and K ₂ O are components added to facilitate the dissolution of glass and to control the coefficient of linear expansion and viscosity, and the content thereof is 10 to 20 parts by weight, Is 12 to 17 parts by weight. When the total amount of these components is more than 20 parts by weight, the coefficient of linear expansion is excessively high and the chemical durability is greatly lowered. On the other hand, when the amount is less than 10 parts by weight, the coefficient of linear expansion becomes too small. The content of each component of the alkali metal oxide is preferably 0.1 to 5 parts by weight of Li ₂ O, 0.1 to 15 parts by weight of Na ₂ O and 0.1 to 10 parts by weight of K ₂ O. It is most preferable that 0.1 to 3 parts by weight of Li ₂ O, 0.1 to 12 parts by weight of Na ₂ O and 0.1 to 5 parts by weight of K ₂ O are most preferable.

Alkali earth metal oxides such as MgO, CaO, SrO, and BaO are components added to facilitate the dissolution of glass, control the coefficient of linear expansion and viscosity, and stabilize the glass, and the content thereof is 1 to 10 parts by weight, Preferably 2 to 6 parts by weight. When the total amount of these components is 10 parts by weight or more, the coefficient of linear expansion becomes too high and the chemical durability is lowered. When the amount is less than 1 part by weight, the solubility and stability of the glass are lowered. The content of each component of the alkaline earth metal oxide is preferably from 0 to 3 parts by weight of MgO, from 0.1 to 8 parts by weight of CaO, from 0 to 2 parts by weight of SrO and from 0.1 to 8 parts by weight of BaO. It is most preferable that 0.1 to 1 part by weight of MgO, 0.1 to 4 parts by weight of CaO, 0 to 1 part by weight of SrO and 0.1 to 4 parts by weight of BaO are preferable.

ZrO ₂ improves chemical durability and prevents alkali swelling, and its content is 8 to 18 parts by weight, preferably 10 to 16 parts by weight. If the amount of ZrO ₂ is more than 18 parts by weight, the glass is liable to be unstable, the glass becomes uneven, the surface tension becomes too large, and the dimensional precision becomes worse or appearance defects occur, making it difficult to obtain a high quality glass lining product. If the amount is less than 10 parts by weight, the chemical durability is deteriorated and alkali swelling occurs.

CoO is a component that imparts color to a glass lining product, and the glass has a deep blue color and has a beautiful appearance. Its content is 0.5 to 2.5 parts by weight, preferably 1 to 2 parts by weight.

Usually by stirring well to glass using a stirrer (Stirrer) so that the glass melt are well mixed to be homogenized at the time of melting, but major surface can be homogenized together by a heterogeneous glass stirring, a high concentration of ZrO ₂ (ZrO ₂ -rich ) The homogenization of the glass melt is not easy even if it is stirred. Theoretically, this is based on the Dynactivity Theory of Equation (1) below. If the product of the difference of the surface tension and the specific gravity difference of the different heterogeneous glasses is negative, the homogenization can be achieved by stirring. If the concentration of ZrO ₂ is high (ZrO ₂ -rich) The glass melt and the normal glass melt do not homogenize if the product of surface tension difference and specific gravity difference shows a positive value.

Therefore, the present invention In order to obtain glass of the content of ZrO ₂ excess when mixed with 30% to 40% is further added by weight as a percentage than the content of the ZrO ₂ target at the time of raw material mixing even if the sedimentation of the ZrO ₂ component aiming The content of ZrO ₂ can be obtained.

[Formula 1]

_{(σ 1 - σ 2) ·} (ρ 1 -ρ 2) <0

Here, σ: surface tension, ρ: specific gravity

Hereinafter, a method for producing the top glaze for the glass lining of the present invention will be described.

First, a glass raw material is prepared so that a desired glass can be produced.

Glass raw material is 55~75 parts by weight of SiO _2, Al ₂ O ₃ 0.5~5 parts by _{weight, Li 2 O + Na 2 O} + K 2 O 10~20 parts by weight, MgO + CaO + SrO + BaO 1 ~ 10 parts by weight , 8 to 18 parts by weight of ZrO ₂ , and 0.5 to 2.5 parts by weight of CoO.

At this time, the target content of ZrO ₂ may be further mixed in an amount of 30 to 40% by weight based on 8 to 18 parts by weight. For example, 13 to 14 parts by weight in the case of 10 parts by weight of ZrO ₂ target content.

Next, the glass raw material thus prepared is put into a glass melting furnace, melted at about 1,300 to 1,600 DEG C, vitrified, and then formed into a ribbon by using a water-cooled twin roller in which the melt is poured into water and then quenched and dried or pulverized or rotated. .

At this time, the grinding of the glass is ground with a ball mill according to the desired particle size, and when a micronized powder is desired, a pulverizing apparatus such as a jet mill or a fine mill can be utilized.

The crushed glass powder (Frit) can be used as a top glaze for glass lining, and the crushed glass powder is mixed with crystalline SiO ₂ or ZrO ₂ powder as a filler in a proportion of 1 to 5 wt% as a glass powder, Can be used.

When the crystalline SiO ₂ or ZrO ₂ powder is mixed as less than 1% by weight as a filler, the effect of improving the chemical resistance is insufficient. When the crystalline SiO ₂ or ZrO ₂ powder is mixed at 5% by weight or more, the chemical resistance is further improved. It is preferably added in an amount of 1 to 5% by weight in order to deteriorate the glass properties.

Hereinafter, preferred embodiments of the present invention will be described. However, the present embodiment is illustratively shown for the sake of understanding the present invention, and thus the scope of the present invention is not limited thereto.

[Example]

A target content of the glass does this not obtained glass composition (8 to 18 parts by weight) was the first target by the ZrO ₂ precipitated at the time of melting of the raw material ZrO ₂ component is lowered by the precipitation, ZrO ₂ component in the present invention are described below embodiments obtained how the content of the ZrO ₂ component which aims by dissolving the raw material by adding 30 to 40% by weight in terms of percentage ZrO ₂ ingredient basis in the glass raw material to obtain shows an example and comparative examples in tables 1 and 2.

Table 1 and Table 2 show the results of the target composition, the raw material composition and the analysis composition in each of the examples and the comparative examples, wherein the target composition is the target glass composition for the raw material combination, , The target composition is basically the same as the target composition. However, in the embodiment, the composition is such that the ZrO ₂ component is added in an amount of 30 to 40% by weight based on the percentage of the ZrO ₂ component, In the comparative example, the ZrO ₂ component is not added, which is the same as the target composition.

The analytical composition is a composition obtained by dissolving the mixed raw materials and analyzed by ICP-OES wet analysis. In the examples, the ZrO ₂ component shows the additional effect. In the comparative example, since the ZrO ₂ component is not added, the ZrO ₂ Lt; _{RTI ID = 0.0} &gt; ZrO2 &lt; / _RTI &gt; In the comparative example, even if the raw materials are mixed in the same manner as the glass composition of the present invention, the composition of the glass obtained by the loss due to sedimentation of the ZrO ₂ component at the time of actual glass dissolution is shown to be out of the scope of the present invention.

In the melting method of glass, the mixed raw materials were melted by heating in an electric furnace at 1,500 ° C for 1 hour using a platinum crucible, and they were poured into a quartz rod at intervals of 30 minutes in the middle of melting to homogenize the glass. The glass produced by the above method was subjected to wet quantitative analysis using ICP-OES to confirm the difference between the target composition, the composition of the raw material and the composition of the analyzed composition by ICP analysis.

As can be seen from Tables 1 and 2, in the examples of the present invention, the raw material composition in which the ZrO ₂ component was added in an amount of 30 to 40 wt% in the target composition range of glass was used. When the analysis composition after the glass melting was compared, but close to, and in the Comparative examples that do not add the ZrO ₂ component content is reduced in joseongsang ZrO ₂ component due to the settling of the ZrO ₂ component it can be seen to significantly occurs.

This is because uniformly mixed raw materials are diffused over the melting time and become homogeneous vitrification when melted. However, a substance having a high specific gravity (5.73) and a high melting point (2,715 ° C) like ZrO _{2 in a} raw material is diffused But rather a large amount of sediment.

division Example 1 Example 2 Example 3 goal
Furtherance Raw material
Furtherance analysis
Furtherance goal
Furtherance Raw material
Furtherance analysis
Furtherance goal
Furtherance Raw material
Furtherance analysis
Furtherance Furtherance
(weight%) SiO ₂ 65 65 65.2 65.9 65.9 65.8 63.9 63.9 64 R ₂ O 17 17 16.7 16.7 16.7 16.6 15.8 15.8 15.9 RO 4.5 4.5 4.5 4.8 4.8 4.9 4.8 4.8 4.6 Al ₂ O One One One 1.1 1.1 1.1 1.3 1.3 1.2 ZrO ₂ 11 15 11 10.2 14.2 10.3 13 18 13.2 CoO 1.5 1.5 1.6 1.3 1.3 1.3 1.2 1.2 1.1 Composition total
(weight%) 100 104 100 100 104 100 100 105 100

division Example 4 Comparative Example 1 Comparative Example 2 goal
Furtherance Raw material
Furtherance analysis
Furtherance goal
Furtherance Raw material
Furtherance analysis
Furtherance goal
Furtherance Raw material
Furtherance analysis
Furtherance Furtherance
(weight%) SiO ₂ 63.5 63.5 63.6 65 65 70 68 68 69.9 R ₂ O 17 17 16.8 17 17 16 18 18 17.8 RO 4 4 4.1 4.5 4.5 4.5 4 4 4.1 Al ₂ O One One One One One One One One 1.2 ZrO ₂ 13.5 18 13.5 11 11 7 8 8 5.9 CoO One One One 1.5 1.5 1.5 One One 1.1 Composition total
(weight%) 100 104.5 100 100 100 100 100 100 100

Table 3 shows the acid resistance and alkali resistance test results of the glass samples obtained after dissolution in the examples and comparative examples of Tables 1 and 2.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Acid resistance
Annual corrosion rate
(mm / year) 0.16 0.15 0.12 0.11 0.23 0.26 Alkali resistance
Annual corrosion rate
(mm / year) 0.48 0.50 0.35 0.32 0.67 0.75

The annual corrosion rate (mm / year) corresponding to the acid resistance and alkali resistance corresponds to the better value. The acid resistance required for the glass lining product is the annual corrosion rate of less than 0.2 mm / year, Require an annual corrosion rate of less than 0.5 mm / year.

As can be seen from the examples in Table 3, in the examples in which the ZrO ₂ component was further added to obtain the desired composition after dissolution, the acid resistance showed an annual corrosion rate of less than 0.2 mm / year, and the alkali resistance was 0.5 mm / year The following annual corrosion rates.

The comparative examples show that the ZrO ₂ precipitates in the glass in which the raw materials are mixed and melted in accordance with the target composition without addition of the ZrO ₂ component, so that the ZrO ₂ content is much lower than the target composition, resulting in poor acid resistance and chemical resistance give.

2 and 3 show an apparatus for evaluating acid resistance, which is carried out by 20% hydrochloric acid breaking according to the international standard of ISO 28706-2. The glass lining specimen coated with a glass glaze (Enamel) 33x10 ^-7 / ℃ Borosilicate glass (commercially available Pyrex glass) Put it in specimen holder (5) and expose it to hydrochloric acid. Heating is carried out by means of a jacket heater (6) and the heating conditions are such that the condensate collected via the Liebig condenser (4) maintains a temperature within the range of 8 ml ± 2 ml per 3 minutes, this time being maintained for 7 days (168 hours) .

If the mass loss is less than 8 mg, the measurement is carried out for 14 days. The specimens before and after the measurement are washed with acetic acid and dried at 110 ± 5 ° C for 2 hours and then weighed. The results are the mean value after two runs.

Figs. 4 to 6 show the apparatus for evaluating alkali resistance, and the alkali resistance test of the present invention is conducted in a stainless steel vessel 8 which is in accordance with the international standard of ISO 28706-4 and is resistant to an aqueous alkali solution. The specimen 7 is mounted in a stainless steel vessel 8 and the alkaline solution is exposed to the liquid area under conditions specified in the surface of hot 0.1 M or 1.0 M sodium hydroxide solution 9. The temperature of the sodium hydroxide solution (9) should be maintained at 80 ° C and the test time shall be maintained for 24 hours. The results are shown in one measurement.

As a result of the weight reduction, the corrosion rate (mm / year) can be calculated by equations (2) and (3).

[Formula 2]

Total mass loss per unit area,

[Formula 3]

Mass loss per unit area hour,

Where m _{s is the} initial mass (g), m _{f is the} final mass (g), A is the exposed area of the specimen (m ² )

(법랑재료밀도 2.5g/cm³ 가정)Annual corrosion rate,

(Assuming an enamel material density of 2.5 g / cm ³ )

Table 4 shows experimental results in which acidity and alkali resistance are further enhanced by adding crystalline SiO ₂ or ZrO ₂ powder as a filler to the ground glass obtained from the glass of Example 3 of Table 1 of the present invention .

In the examples of Table 4, when the crystalline SiO ₂ or ZrO ₂ powder is added in an amount of 1 to 5% by weight, the acid resistance and chemical resistance are further improved. The composition ratios shown in Table 3 indicate the proportion of each powder added as a filler. In Comparative Example 3, 0.5% by weight of the crystalline SiO ₂ or ZrO ₂ powder was added, and the thermal properties of the glass did not change much, but the addition effect was not obtained. In Comparative Examples 4 and 5, the crystalline SiO ₂ or ZrO ₂ powder was changed to 10 In the case of adding by weight, the acid resistance and the chemical resistance are improved remarkably, but the thermal properties such as inherent spreadability of the glass are deteriorated.

division Mother glass
Furtherance Example 5 Example 6 Example 7 Example 8 Example 9 Comparative Example 3 Comparative Example 4 Comparative Example 5 Filler content (percent based on the parent glass weight,% by weight) Furtherance
(wt%) SiO ₂ 64 One 0 5 0 2 0 10 0 R ₂ O 15.9 - - - - - - - - RO 4.6 - - - - - - - - Al ₂ O 1.2 - - - - - - - - ZrO ₂ 13.2 0 One 0 5 3 0.5 0 10 CoO 1.1 - - - - - - - - Sum
(wt%) 100 One One 5 5 5 0.5 10 10 Acid resistance
(Annual corrosion rate, mm / year) 0.1 0.1 0.05 0.05 0.05 0.12 0.01 0.01 Alkali resistance
(Annual corrosion rate, mm / year) 0.32 0.32 0.23 0.23 0.23 0.35 0.17. 0.17 Glass Properties ○ ○ ○ ○ ○ ○ X X

It is to be understood that the scope of the present invention is not limited to the embodiments of the present invention and that the scope of the present invention is not limited thereto, It is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

1: Crucible
2: molten glass
3: ZrO ₂ precipitate
4: Liebig condenser
5: Borosilicate glass specimen holder
6: Jacket heater
7: The Psalms
8: Stainless steel vessel
9: Sodium hydroxide solution

Claims (8)

55 to 75 parts by weight of SiO ₂ ,
10 to 20 parts by weight of R ₂ O (wherein R represents Li, Na or K)
1 to 10 parts by weight of R'O (wherein R 'represents Mg, Ca, Sr or Ba)
ZrO ₂ 8 ~ 18 parts by weight,
0.5 to 5 parts by weight of Al ₂ O ₃ , and
0.5 to 2.5 parts by weight of CoO,
And 1 to 5 parts by weight of a crystalline SiO ₂ or ZrO ₂ powder as a filler.
delete SiO _2, R ₂ O (where, R represents a Li, Na or K), R'O (where, R 'represents a Mg, Ca, Sr or Ba), ZrO _2, the Al ₂ O ₃ and CoO Mixing (S1) a glass raw material;
(S2) melting and vitrifying the glass raw material produced in the step S1;
Cooling and milling the melt produced in the step S2 (S3);
/ RTI &gt;
Method for producing a top coat glaze for glass lining according to claim 1, further comprising the step of adding crystalline SiO ₂ or ZrO ₂ powder 1-5 parts by weight of the glass powder prepared in the above step S3.
delete The method of claim 3,
Wherein the step S 1 is a step of mixing 55 to 75 parts by weight of SiO ₂ , 10 to 20 parts by weight of R ₂ O (where R represents Li, Na or K) and 1 to 10 parts by weight of R'O Ca, Sr, or Ba), 10.4 to 25.2 parts by weight of ZrO ₂ , 0.5 to 5 parts by weight of Al ₂ O ₃ , and 0.5 to 2.5 parts by weight of CoO to produce a glass raw material. / RTI &gt;
The method of claim 3,
Wherein the step S2 is a step of melting the glass raw material produced in the step S1 at 1,300 to 1,600 DEG C to vitrify the glass raw material.
The method of claim 3,
Wherein the step S3 is a step of cooling the molten material in water to quench the molten material, and then drying and pulverizing the molten material, or forming the molten material into a ribbon using a water-cooled twin roller that rotates the molten material, and then grinding the ribbon. &Lt; / RTI &gt;
The method of claim 3,
Wherein the milling in the step S3 uses a ball mill, a jet mill or a fine mill.

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