JP2002060247A - Iron-containing enamel glaze and method for producing iron-containing enameled product using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high value-adding method for utilizing slag treated as industrial waste and to settle environmental issues by forming iron-containing enamel glaze using the slag. SOLUTION: Starting materials containing <40 wt.% slag discharged from a cupola or a blast furnace for iron manufacture, 20-50 wt.% silica rock, 30-60 wt.% borax, 1-20 wt.% alkali metallic carbonate, 0-10 wt.% barium carbonate and 1-2 wt.% at least one of compounds of cobalt, nickel and copper are fritted and <2 pts.wt. borax and 2-10 pst.wt. clay are added to 100 pts.wt. of the resulting frit, comminuted and mixed to prepare particles having 10-35 μm average particle diameter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an iron-based enamel glaze and a method for producing an iron-based enamel product using the same, and more particularly, to a method of coating a slag that has been conventionally treated as industrial waste with a coating material of an iron-based material. The present invention relates to techniques that are skillfully used as components.

[0002]

BACKGROUND ART Conventionally, an organic polymer has been used as a coating material for covering the surface of an iron-based material such as a cast iron casting to protect the surface and improve the design, and to prevent the generation of rust and the like. Organic coatings mainly composed of, or inorganic coatings made by baking inorganic materials such as enamel glaze are well known, but the former organic coatings are heat-resistant. There is a problem in the properties and durability, and the elution of organic components has been regarded as a problem from recent studies, so the safer and more durable coating material is Coatings are attracting attention.

[0003] On the other hand, slag (slag) discharged from a blast furnace for ironmaking during iron refining and slag (slag) discharged when melting cast iron in a cupola are also called noro, and most of them are industrial waste. Although it is treated as a waste, there is a limit to its disposal due to environmental problems. Therefore, it is desired to develop a method of utilizing such slag with high added value.

[0004] As a conventional method of using such slag, it has been studied to use it as a raw material for cement, brick, fertilizer, and the like, and to use slag wool in the fields of heat insulating materials and sound absorbing materials. In addition to, or instead of, the existing fields of use, it is desired to use them in new fields, and if it can further increase the added value, such slag can be reduced from the level of industrial waste. It can be raised to the level of useful resources.

[0005]

Under such circumstances, the present inventors have conducted various studies on the effective use of such slag discharged from a cupola or a blast furnace for steelmaking, and found that such slag is an inorganic mixture. Focusing on silicon, including silicon,
It contains compounds such as magnesium, calcium, and aluminum, and is used as a glaze component in the production of iron-based enamel products, making it a safer, more durable, and more effective inorganic coating. It has been found that an iron-based enamel product in which is formed can be advantageously obtained.

The present invention has been completed on the basis of such findings, and the object of the present invention is to form an iron-based enamel glaze using slag that has been conventionally treated as industrial waste. In addition, by producing an iron-based enameled product using such a glaze, the use of such a slag with a high load value can be achieved, and furthermore, it can greatly contribute to environmental problems.

[0007]

The present invention provides an enamel glaze used as a coating material for an iron-based material to reduce up to 40% by weight of slag discharged from a cupola or a blast furnace for steelmaking. In the proportion of and quartzite:
20 to 50% by weight, borax: 30 to 60% by weight, alkali metal carbonate: 1 to 20% by weight, barium carbonate: 0 to 1
A material obtained by fritting a raw material further containing 0% by weight and at least one of each compound of cobalt, nickel and copper: 1 to 2% by weight is used.
With respect to parts by weight, up to 2 parts by weight of borax and 2 to 10 parts by weight of clay are blended, pulverized and mixed, and the average particle size is 10 parts by weight.
As the first embodiment, an iron-based enamel glaze characterized by being prepared into particles of up to 35 μm is employed.

[0008] In the first aspect, the present invention relates to the above-mentioned frit, wherein the frit is converted to Si by weight.
_{O 2: 30~60%, B 2} O 3: 10~35%, Al 2
O ₃ : 7% or less, at least one of Co, Ni and Cu oxides: 0.1 to 0.9%, Na ₂ O: 5-2
0%, BaO: 0~9%, K 2 O and / or Li ₂ O:
The second method is to prepare a composition having a composition of 0 to 2%, CaO: 7% or less, MgO: 5% or less (however, the total amount of BaO, CaO and MgO is 5% or more). It is an embodiment.

In order to solve the above-mentioned problems, the present invention provides an enamel glaze used as a coating material for an iron-based material, which comprises 30-60% by weight of silica, 30-60% by weight of borax, and alkali metal. Carbonate: 1 to 20% by weight, aluminum hydroxide: 0 to 10% by weight, calcium carbonate: 0 to 1%
0% by weight, barium carbonate: 0 to 10% by weight, magnesium carbonate: 0 to 5% by weight, at least one of cobalt, nickel and copper compounds: 1-2% by weight And 6 of the frit is used.
0 parts by weight or more of slag discharged from a cupola or a blast furnace for iron making at a ratio of up to 40 parts by weight, and a total of 100 parts by weight, and further up to 2 parts by weight of borax And 2 to 10 parts by weight of clay,
A third aspect of the present invention is an iron-based enamel glaze which is obtained by pulverizing and mixing to prepare particles having an average particle size of 10 to 35 μm.

[0010] Even in the iron-based enamel glaze according to the third aspect, the frit and the slag are SiO ₂ : 30 to 60% and B ₂ O ₃ : 10 on a weight basis.
_{~35%, Al 2 O 3:} 7% or less, Co, Ni, at least one of the oxides of Cu: 0.1 to 0.9%,
Na ₂ O: 5 to 20%, BaO: 0 to 9%, K ₂ O and / or Li ₂ O: 0 to 2%, CaO: 7% or less, Mg
In the present invention, a composition in which O: 5% or less (however, the total amount of BaO, CaO and MgO is 5% or more) is advantageously employed as the fourth aspect in the present invention. It will be done.

According to the present invention, in the first to fourth aspects, the slag is S as weight based on weight.
_{iO 2: 30~40%, Al 2} O 3: 10~20%, N
_{a 2 O: 0~5%, K} 2 O: 0~0.4%, CaO: 2
0~45%, MgO: 6~13%, Fe 2 O 3: 0~1
_2%, TiO 2: 0.2~1.0% comprising those having a composition, and thus suitably used as a fifth embodiment.

[0012] In the iron-based enamel glaze according to the present invention, as one of the components, slag which has been conventionally treated as industrial waste is used as it is with respect to iron-based materials. As a safe and durable enamel glaze, it exhibits excellent properties and is an economically advantageous enamel glaze.

[0013] The present invention is not limited to the iron-based enamel glaze as described above, but also to a method of manufacturing an iron-based enamel product using such an iron-based enamel glaze. According to a sixth aspect, when enamelling an iron-based material, an iron-based enamel glaze according to any one of the first to fifth aspects is used as a lower glaze, and the glaze is applied to the iron-based material. After coating and baking on the surface of to form a lower coating layer, further, on the lower coating layer, the average particle size is in the range of 15 to 40 μm and the iron-based enamel glaze Also, an enamel glaze prepared in particles having a large average particle diameter is applied as an upper glaze and fired to form an upper coating layer, and the iron-based material is covered with a coating layer consisting of two upper and lower layers. Manufacturing method of iron-based enameled products characterized by being made The one in which to adopt.

According to the method for producing an iron-based enamel product according to the present invention, the above-mentioned iron-based enamel glaze is used as a lower glaze, while a normal enamel glaze having a predetermined average particle size is used as an upper glaze. Therefore, by forming the coating layer composed of the upper and lower two layers on the surface of the iron-based material, a coating layer without pinholes can be advantageously formed on the surface of the iron-based material, and The elution of trace components and the like, which is a concern due to the use of slag as a raw material, can be completely eliminated, and an inorganic coating layer excellent in durability and safety as well as heat resistance can be advantageously formed on the surface of the iron-based material. It is.

In the method for producing an iron-based enamel product, the enamel glaze used as the upper glaze is preferably SiO ₂ : 28 to 60% by weight.
B ₂ O ₃ : 4 to 27%, Al ₂ O ₃ : _{3 to} 14%, Na
₂ O: 6 to 20%, K ₂ O: 0 to 9%, CaF ₂ : 0 to 0%
5%, BaO: 1 to 12%, CaO: 0 to 7%, TiO
_{2: 0~20%,} ZrO _2: relative 0-10% consisting frit 100 parts by weight of the composition, by blending 2-10 parts by weight of the clay, by mixing and grinding, are caused to preparation, which comprises first In a seventh aspect, it is advantageously employed.

In the present invention, in the sixth or seventh aspect of the present invention, the firing of the enamel glaze used as the upper glaze is performed at a temperature lower than the firing temperature of the iron-based enamel glaze used as the lower glaze. It is also carried out by adopting a low firing temperature,
An eighth aspect may also be advantageously employed, whereby an upper coating layer is effectively formed thereon without adversely affecting the lower coating layer formed with such an iron-based enamel glaze. It can be formed into

Further, a ninth aspect of the present invention resides in that in any one of the sixth to eighth aspects described above, a cast iron casting is used as the iron-based material.
With the iron-based enamel glaze according to the present invention, a durable and useful coating layer can be easily formed, and
As a result, a high quality iron-based enamel product can be advantageously obtained.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Incidentally, the present invention as described above has the following features.
The slag used in the process is a cupola for melting cast iron.
Or from the blast furnace for steelmaking used in iron smelting.
Slag, which is also called slag, and its components
Will vary depending on melting or refining conditions
But generally, on a weight basis, SiO 2_Two: 30-40
%, Al_TwoO _Three: 10-20%, Na_TwoO: 0-5%,
K_TwoO: 0 to 0.4%, CaO: 20 to 45%, Mg
O: 6 to 13%, Fe_TwoO_Three: 0 to 12%, TiO_Two:
What has a composition of 0.2 to 1.0% is the present invention.
In other words, it is preferably used.

In the present invention, such slag is an inorganic mixture, which contains useful components such as MgO, CaO, and Al ₂ O ₃ in addition to SiO _2. From these locations, these ingredients were skillfully used as glaze raw materials, and in order to constitute an effective iron-based enamel glaze, such slag was used as a part of the frit raw material in the enamel glaze or as a mill compounding material. It is.

Specifically, when slag discharged from a cupola or a blast furnace for steelmaking is used as a part of a frit raw material, the slag is blended in a ratio of up to 40% by weight, and further added thereto. , On a weight basis,
Silica stone: 20 to 50%, borax: 30 to 60%, alkali metal carbonate: 1 to 20%, barium carbonate: 0 to 10%,
By preparing a raw material in which at least one of cobalt, nickel, and copper compounds: 1 to 2% is blended, and melting and solidifying it in the same manner as before,
The desired vitreous frit is formed.

In the frit-forming raw material, if the compounding ratio of the slag exceeds 40% by weight, it becomes difficult to prepare an effective frit in the enamel glaze. It is necessary to use in proportions, and also in the compounds of silica, borax, alkali metal (at least one of lithium, sodium and potassium), cobalt, nickel and copper compounds incorporated in such slag. At least one kind of compound becomes a necessary oxide by firing, thereby promoting vitrification, improving adhesion with iron, or adjusting the coefficient of thermal expansion, and the like. , To form a frit having good adhesion to iron, but in the present invention, in order to provide a frit for forming an effective coating layer, It's and thus induced to blend in boss was amount.

And, to such a frit of the raw material,
In which, preferably, on a weight basis, S
iO_Two: 30-60%, B_TwoO_Three: 10 to 35%, Al
_TwoO _Three: 7% or less, of each oxide of Co, Ni and Cu
At least one of the following: 0.1-0.9%, Na_TwoO: 5
20%, BaO: 0-9%, K_TwoO and / or Li_TwoO
(K_TwoO or Li_TwoO or K_TwoO + Li
_TwoO): 0 to 2%, CaO: 7% or less, MgO: 5% or less
Below (however, the total amount of BaO, CaO and MgO is 5% or more
That is prepared to give a composition
It is desirable that this provides an effective coating on the surface of the iron-based material.
It is possible to obtain an enamel glaze that can form a covering layer.
You.

Incidentally, SiO _{2 which} is a component constituting such a frit is a glassy main component,
When the amount added is small, whereas no longer obtained constitute a valid glassy and often, from where the melt temperature is increased, its content is preferably kept to within a range of 30% to 60%, also, B ₂ O ₃ is a glass-promoting and wettability with iron, as a component of improving the fluidity, desirably allowed to contain in the proportion of 10% to 35%, further Al ₂
O ₃ is used as a component for adjusting the coefficient of thermal expansion. As the content of O ₃ increases, the thermal expansion property increases and the melting temperature also increases. Therefore, O ₃ is preferably contained at a ratio of 7% or less. Becomes In addition, Co, Ni, Cu
Each oxide of CoO, NiO, and CuO is added and contained as a component for improving the adhesion between the glaze and iron.
The content of at least one of these oxides is limited to about 0.1 to 0.9% because the effect is reduced, the coloration is caused, and the cost is increased.
O, CaO, and MgO are all used as components for improving the adhesion to iron, and if the content thereof is small, the coefficient of thermal expansion decreases. Therefore, the total amount of the three is 5%. It is added and contained as described above. In addition, Na ₂ O, K ₂ O, and Li ₂ O are included as a component for adjusting the thermal expansion coefficient or as a flux component. If the content is large, the thermal expansion coefficient increases, and the frit becomes soft. Therefore, the Na ₂ O component is contained at a ratio of 5 to 20%, and the K ₂ O and / or Li ₂ O is contained at a ratio of 0 to 2%.

In the present invention, from the frit obtained by using the slag as one component of the raw material as described above, in order to obtain a desired iron-based enamel glaze, 100% of such frit is used. With respect to parts by weight, up to 2 parts by weight of borax and 2 to 10 parts by weight of clay are used as a mill compounding material, and the three are compounded and pulverized and mixed to have an average particle size of 10%. The particles are prepared into particles having a size of about 35 μm, and are used as the target iron-based enamel glaze (A).

In the preparation of the iron-based enamel glaze (A), borax as a mill compounding material to be mixed with the frit is mainly used for dispersibility of the glaze (lower glaze) and melting temperature of the glaze (lower glaze). It is compounded as a component for promoting the vitrification. Further, when the added amount is large, the drying strength is reduced, and the film is not formed due to the imbalance of the components for firing the glaze (lower glaze). , And from the point of causing problems such as pinhole formation due to gas separation during decomposition,
As described above, it is necessary to add up to 2 parts by weight, and the same clay as a mill compounding material is mainly used to maintain the dry strength and impart the coating property of glaze (lower glaze), It is a component that improves the dispersibility of the frit and the viscosity of the underglaze liquid.
At a ratio of 10 to 10 parts by weight, the compound is added and blended. If the amount of such a clay is too small, viscosity may not be obtained, and a film may not be formed.On the other hand, if the amount of the clay is too large, the properties of the film may be adversely affected, and the thin film after firing may be formed. (Coating layer) causes a problem that the formation becomes difficult.

Further, according to the present invention, as described above, the desired iron-based enamel glaze is produced by blending borax and clay as a mill compounding material with the fritted material and pulverizing and mixing. The average particle size is 1
It is necessary to prepare particles of 0 to 35 μm.
By controlling such an average particle size, a film effective as a glaze on the surface of the iron-based material can be effectively formed. The average particle size is 10 μm.
If it is smaller than m, uniform film formation becomes difficult, and there is a problem that it is not possible to obtain a uniform coating layer after baking, and if it is larger than 35 μm, there is a portion that is not melted even by baking, and workability is increased. However, there is a problem that the coating layer after firing becomes a layer having an uneven thickness.

Further, the iron-based enamel glaze according to the present invention can be prepared by using a slag as one of the mill compounding materials in addition to the slag as one component of the raw material of the frit as described above. In that case, frit,
Silica: 30-60% by weight, borax: 30-60% by weight, carbonate of alkali metal: 1-20% by weight, aluminum hydroxide: 0-10% by weight, calcium carbonate: 0-10% by weight, barium carbonate: A frit of a raw material having a composition of 0 to 10% by weight, magnesium carbonate: 0 to 5% by weight, at least one of cobalt, nickel, and copper compounds: 1 to 2% by weight is used. .

Here, each component of the raw material for providing such a frit is converted into a necessary oxide by calcination, and the above-mentioned ratio is determined so as to form a frit having good adhesion to iron. Will be used.
In addition, the fritting of such raw materials is carried out in the same manner as in the prior art, by pulverizing a mixed powder containing predetermined components, drying and melting the mixture, quenching, vitrifying, and further pulverizing the vitrified product. And make it a frit.

The frit obtained in this manner is used, and slag discharged from a cupola or a blast furnace for steelmaking is compounded as a mill compounding material. As in the case of the iron-based enamel glaze (A) used as a raw material, borax and clay are blended, pulverized and mixed, and the average particle size is 10 to 10.
By preparing particles having a size of 35 μm, the desired iron-based enamel glaze (B) is obtained.

Incidentally, for such a frit product,
When compounding the slag as a mill compounding material, the slag is compounded in a proportion of up to 40 parts by weight (not including 0 part by weight) with 60 parts by weight or more (less than 100 parts by weight) of the frit product, and the total The amount must be 100 parts by weight, and if the amount of the slag is too large, the properties as a glaze deteriorate and it becomes difficult to form a uniform coating layer. And one of such frit and slag
With respect to 00 parts by weight, borax was mixed in a ratio of up to 2 parts by weight and clay was mixed in a ratio of 2 to 10 parts by weight, and as in the case of the iron-based enamel glaze (A), the average particle size The desired iron-based enamel glaze (B) is prepared by pulverizing and mixing the particles so that the particles have a diameter of 10 to 35 μm.

Further, the preparation of such an iron-based enamel glaze (B)
In the production, the frit and the slag are combined with the iron
The same as the composition of the frit in the enamel glaze (A)
In addition, on a weight basis, SiO_Two: 30-60%, B_Two
O_Three: 10 to 35%, Al_TwoO _Three: 7% or less, Co, N
i, at least one of Cu oxides: 0.1 to
0.9%, Na_TwoO: 5 to 20%, BaO: 0 to 9%,
K_TwoO and / or Li_TwoO: 0 to 2%, CaO: 7% or less
Lower, MgO: 5% or less (however, BaO, CaO, and MgO
Is 5% or more).
It is blended, and by this, the iron-based enamel glaze (A)
A glaze with the same excellent properties as
Because

When the iron-based enamel glaze (A) or (B) is used to enamel-process an iron-based material such as a cast iron casting, the iron-based enamel glaze (A) or (B) is used. Used as an underglaze, it is applied to the surface of an iron-based material and baked to form a lower coating layer.
On the lower coating layer, a predetermined enamel glaze was applied as an upper glaze and fired to form an upper coating layer,
By making such an iron-based material covered with a coating layer consisting of two layers, an iron-based enamel product having no pinholes and having excellent properties can be obtained.

By the way, in manufacturing such an iron-based enameled product, as the iron-based material, all iron-based materials are to be used. Particularly, in the present invention, Cast iron castings are advantageously targeted, and it is easy to obtain enamel products with a pinhole-free, safe and durable coating on the surface of such cast iron castings. Prior to enamelling such an iron-based material, degreasing and washing are performed using an organic solvent, a detergent, or the like by a usual method.
Drying is performed.

On the other hand, the above-mentioned prescribed compound which gives the iron-based enamel glaze (A) or (B) is mixed and pulverized by a mill or the like,
Slurry with an average particle size of 10 to 35 μm is prepared at a solids concentration of the order of 60 to 70%.

Next, the obtained iron-based enamel glaze (A)
Alternatively, the slurry composed of (B) is applied to a predetermined surface of an iron-based material by a known method such as dipping, brushing, or spraying, and is performed at room temperature or at 100 to 200 ° C. × 10
Drying is performed under heating under conditions such as ~ 20 minutes.
By baking at a temperature of 00 to 900 ° C. for 1 to 10 minutes, a predetermined glaze (A) or (B) is applied to the surface of the iron-based material.
Is formed.

After that, if only such a lower coating layer is provided, there is a concern that generation of pinholes or elution of trace components may occur. An enamel glaze in the range of ４０40 μm and prepared in particles having an average particle diameter larger than that of the iron-based enamel glaze (A) or (B) forming the lower coating layer is applied as an upper glaze. By sintering, the upper coating layer is formed, so that the iron-based material is covered with the coating layer consisting of the upper and lower two layers, so that a good quality iron-based enamel product can be obtained. It is.

As the enamel glaze used as the upper glaze used herein, generally, glazes of ordinary iron-based enamel products, particularly those used as the upper glaze, can be used as they are. In this case, it is desirable to use a glaze prepared according to the lower coating layer. In this case, the frit is SiO ₂ : 2 on a weight basis.
_{8~60%, B 2 O 3:} 4~27%, Al 2 O 3: 3~
_{14%, Na 2 O: 6~20} %, K 2 O: 0~9%, C
_{aF 2: 0~5%, BaO:} 1~12%, CaO: 0~
_{7%, TiO 2: 0~20%} , ZrO 2: is 0 to 10% a composition intended, so that advantageously used.

Of the components constituting the frit that gives the upper glaze, SiO ₂ is a vitreous skeleton component, Al ₂ O ₃ is a hardness improving component, and B ₂ O ₃ is a vitrification promoting component. , Na ₂ O and K ₂ O are thermal expansion adjusting components, Ba
O and CaO are also mainly used as a thermal expansion adjusting component, TiO ₂ and ZrO ₂ are mainly used as a cloudy color imparting component, and CaF ₂ is mainly used as a gloss imparting component, respectively. From the viewpoints of thermal expansion, hardness, pinhole, aesthetics, and the like, a composition within the above range is advantageously employed.

Using such a frit, 2 to 10 parts by weight of clay is blended with 100 parts by weight of the clay and mixed and pulverized by a mill or the like to obtain an enamel glaze as an upper glaze. The slurry is to be prepared. At this time, the particles obtained by such mixing and pulverization have an average particle size in the range of 15 to 40 μm, and have the above-mentioned iron-based enamel as the lower glaze. It is necessary that the glaze (A) or (B) is prepared as particles larger than the average particle diameter of the particles. Thus, by making the average particle size of the upper glaze larger than that of the lower glaze, the adhesion of each coating layer formed by the glaze is further enhanced, and An integral coating layer with excellent durability can be advantageously formed.

The slurry of the glaze prepared as such an underglaze generally has a solid content of 60 to 70%, and the slurry thus prepared is mixed with the iron-based enamel glaze described above. Using A) or (B), apply the method of immersion on the lower glaze layer (lower coating layer) of the lower glaze-applied iron-based material, or apply with a brush or apply with a spray. After the glaze coating layer is formed, room temperature or 100
After being dried by heating under conditions such as ~ 200 ° C x 5-10 minutes, baking is performed in the same manner as in the prior art,
Thus, in the upper glaze coating layer, the upper coating layer is integrally formed on the lower coating layer made of the iron-based enamel glaze (A) or (B).

The baking operation for forming the upper coating layer using the upper glaze can be generally performed by heating at a temperature of 800 to 900 ° C. for 1 to 10 minutes. According to the present invention, the firing temperature for forming the upper coating layer is set to be lower than the firing temperature for forming the lower coating layer (lower glaze layer). The melting of the lower glaze layer, which is the coating layer, is avoided, so that the problem of film defects caused thereby is not caused.

On the lower coating layer formed by using the iron-based enamel glaze according to the present invention thus obtained as a lower glaze,
Furthermore, in the case of iron-based enamel products covered with a two-layer coating layer consisting of an upper coating layer formed using a predetermined enamel glaze as an upper glaze, there are problems such as pinholes and elution of trace components. It is a safe and durable iron-based enameled product without any.

[0043]

EXAMPLES Examples of the present invention will be described below to clarify the present invention more specifically. However, the present invention is not limited by the description of such examples. Not that, of course. Also,
In the present invention, various changes, modifications, improvements, etc., based on the knowledge of those skilled in the art, in addition to the following embodiments, in addition to the above-described specific description, without departing from the spirit of the present invention. It should be understood that can be added. All parts and percentages in the following examples are shown on a weight basis unless otherwise specified.

Example 1 First, as a slag, the following Table 1 was discharged from Cupola.
Was prepared.

[0045]

[Table 1]

In addition, 24 parts of silica stone, 37 parts of borax, 5 parts of aluminum hydroxide, 11 parts of sodium carbonate, 3 parts of potassium carbonate, 3 parts of lithium carbonate, 7 parts of calcium carbonate, and 1 part of magnesium carbonate. Part, cobalt trioxide: 1 part, and barium carbonate: 8 parts, were melted and solidified, and further pulverized to obtain a frit product having the composition shown in Table 2 below. .

[0047]

[Table 2]

Next, the slag (slag) prepared above
1 of a mixture consisting of 10 parts of
For 00 parts, borax (Na ₂ B ₄ O)
One part of ₇ · 10H ₂ O) is mixed with 5 parts of Frogme clay, and the mixture is pulverized and mixed with a mill to obtain a glaze having an average particle size of 27 μm and a solid content of 52.8%. A slurry was prepared.

Then, the obtained glaze slurry was used as a lower glaze, applied to the surface of a cast iron bar by dipping and dried at 25 ° C. for 1 hour, and then dried at 850 ° C. By baking for 5 minutes, the film thickness becomes 150
A μm underglaze film (lower coating layer) was formed on the surface of the cast iron bar.

On the other hand, a frit shown in Table 3 below was prepared as an upper glaze frit, and 5 parts by weight of Frogme clay was blended with 100 parts by weight of the frit, and the mixture was pulverized by a mill. As a result, a glaze slurry for top glaze consisting of particles having an average particle size of 32 μm and having a solid content of 52.3% was obtained.

[0051]

[Table 3]

Using the glaze slurry for the upper glaze prepared as described above, it was applied by dipping onto the lower glaze layer of the surface of the cast iron bar previously obtained, and then was applied at 27 ° C. for 1 hour. Drying is performed, and then baking is performed at a temperature of 800 ° C. for 5 minutes to form an upper glaze layer (upper coating layer) having a thickness of 100 μm. A cast iron bar having a coating layer composed of layers was obtained.

Microscopic observation of the thus obtained enameled product provided with the two-layered coating layer showed that no pinholes existed in such a coating layer. In addition, such an enamel product has a uniform and uniform coating layer on its surface, and there is no fear of elution of trace components from the inside. Further, the enamel product is safe, durable, and of good quality. Admitted.

On the other hand, the above frit compound: 90
Parts, slag: 10 parts, borax: 1 part, and frog eyes clay: 5 parts When the mixture is pulverized by a mill, the pulverizing operation is sufficiently performed to obtain a lower glaze having an average particle diameter of 6 μm. A glaze slurry was prepared and used to form a lower glaze layer (lower coating layer) on the surface of a cast iron bar in the same manner as described above. In such a state, the glass was not sufficiently vitrified, was unevenly adhered to the surface of the cast iron bar, in other words, had a surface property of not forming a film.
Did not form.

Example 2 In Example 1, the mixing ratio of the frit and the slag mixed to obtain the glaze slurry for the underglaze was changed to 70 parts of the former and 30 parts of the latter. Example 1
In the same manner as described above, a glaze slurry for lower glaze was prepared.

Next, a lower glaze layer (lower coating layer) was formed on the surface of the cast iron bar in the same manner as in Example 1 using the prepared glaze slurry for lower glaze. The upper glaze layer (upper coating layer) was formed using the same glaze slurry for upper glaze as in Example 1 to obtain an enamel product having a coating layer having a two-layer structure formed on the surface of a cast iron rod.

No pinholes were found in the enamel product thus obtained, and the product was found to be of good quality.

Example 3 Along with 10 parts of the slag used in Example 1, 33 parts of silica stone,
Borax: 52 parts, sodium carbonate: 10 parts, potassium carbonate: 3 parts, lithium carbonate: 3 parts, barium carbonate: 5 parts,
Cobalt oxide: After pulverizing and mixing 1 part with a mill,
By heating, melting and rapidly cooling at a temperature of 1200 ° C., the mixture was vitrified to obtain a frit for lower glaze.

Next, 100 g of this frit for underglaze was used.
Parts, borax (Na ₂ B ₄ O ₇
One part of 10H ₂ O) and 5 parts of Frogme clay are blended and crushed and mixed by a mill to prepare a glaze slurry for the lower glaze similar to that in Example 1, and further to a cast iron rod. Example 1
A lower glaze layer (lower coating layer) is formed in the same manner as described above, and an upper glaze layer (upper coating layer) similar to that in Example 1 is further formed thereon. The product was made.

The enamel product obtained in this manner is of good quality without pinholes, and the two-layer coating layer adheres tightly to the surface of the cast iron bar to form an integral structure. It was confirmed that the product had good durability and good quality.

[0061]

As is clear from the above description, the iron-based enamel glaze according to the present invention can be advantageously used for enamelling of iron-based materials. In this regard, slag that had been treated as industrial waste has been used advantageously, and this has enabled the effective use of value-added slag. Even if such a slag is used as one component of the raw material, an enamel product having excellent durability can be provided as an iron-based enamel glaze.

Further, according to the method for producing an iron-based enamel product according to the present invention, the coating layer has a two-layer structure, and the lower coating layer is formed using the iron-based enamel glaze according to the present invention. As a result, a high-quality enamel product without any risk of pinholes or elution of trace components can be obtained, so that the slag in the glaze can be used more advantageously.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yoshiyuki Iwata 3-2 Izumigaoka-cho, Toki-shi, Gifu (72) Inventor Shigezo Obata 7-606, Ashikaga-cho, Hashima-shi, Gifu (72) Inventor Tada Shimada Aichi 330 (72) Shoji-machi, Moriyama-ku, Nagoya-shi Inventor Shoji Sawaguchi 4-5-651 Meiwa-cho, Tajimi-shi, Gifu F-term (reference) 4D004 AA43 BA06 CA04 CA29 CA45 CC11 DA02 DA03 DA10 DA20 4G062 AA09 BB01 BB05 CC04 CC08 DA04 DA05 DA06 DB01 DB02 DB03 DB04 DC03 DC04 DC05 DD01 DE01 DF01 EA01 EA02 EA03 EB03 EB04 EC01 EC02 EC03 ED01 ED02 ED03 ED04 EE01 EE02 EE03 EF01 EG01 EG01 EG03 FA01 FB02 FB03 FC01 FC01 GA01 F01 FG01 GE02 GE03 HH01 HH03 HH04 HH05 HH07 HH09 HH11 HH12 HH13 HH15 HH17 HH20 JJ01 JJ03 JJ05 JJ07 JJ10 KK01 KK03 KK05 KK07 KK10 MM06 NN32

Claims (9)

[Claims] 1. An enamel glaze used as a coating material for an iron-based material, containing up to 40% by weight of slag discharged from a cupola or a blast furnace for steelmaking, and 20% silica stone.
To 50% by weight, borax: 30 to 60% by weight, alkali metal carbonate: 1 to 20% by weight, barium carbonate: 0 to 10% by weight, at least one of cobalt, nickel and copper compounds: 1 A material obtained by fritting a raw material further containing up to 2% by weight, and blending up to 2 parts by weight of borax and 2 to 10 parts by weight of clay with respect to 100 parts by weight of the frit, and pulverizing and mixing. At least, the average particle size is 10-3
An iron-based enamel glaze characterized by being prepared into particles of 5 μm. 2. The frit according to claim 1, wherein the content of SiO _{2 is} 30 to 60% and the content of B ₂ O _{3 is} 10 to 35 on a weight basis.
%, Al ₂ O ₃ : 7% or less, at least one of oxides of Co, Ni, Cu: 0.1 to 0.9%, Na ₂
O: 5~20%, BaO: 0~9 %, K 2 O and / or _{Li 2 O: 0~2%, CaO} : 7% or less, MgO: 5%
2. The iron-based enamel glaze according to claim 1, wherein the glaze is prepared so as to give the following composition (however, the total amount of BaO, CaO and MgO is 5% or more). 3. An enamel glaze used as a coating material for an iron-based material, wherein silica stone: 30 to 60% by weight, borax: 30 to 6%
0% by weight, alkali metal carbonate: 1 to 20% by weight, aluminum hydroxide: 0 to 10% by weight, calcium carbonate:
0-10% by weight, barium carbonate: 0-10% by weight, magnesium carbonate: 0-5% by weight, at least one of cobalt, nickel and copper compounds: 1-2% by weight Using a frit product, a slag discharged from a cupola or a blast furnace for steelmaking is mixed in a ratio of up to 40 parts by weight to 60 parts by weight or more of the frit product, and the total amount is 100 parts by weight. And
An iron-based enamel glaze characterized by being prepared by mixing up to 2 parts by weight of borax and 2 to 10 parts by weight of clay, pulverizing and mixing to prepare particles having an average particle size of 10 to 35 μm. 4. The frit product and the slag are based on weight: SiO ₂ : 30 to 60%, B ₂ O ₃ : 1
_{0~35%, Al 2 O 3:} 7% or less, Co, Ni, Cu
At least one of the following oxides: 0.1 to 0.9
_{%, Na 2 O: 5~20%} , BaO: 0~9%, K 2 O
And / or Li ₂ O: 0 to 2%, CaO: 7% or less, M
The iron-based enamel glaze according to claim 3, which is blended so as to give a composition of gO: 5% or less (however, the total amount of BaO, CaO and MgO is 5% or more). 5. The slag is SiO 2 on a weight basis.
_{2: 30~40%, Al 2 O} 3: 10~20%, Na 2
_{O: 0~5%, K 2 O} : 0~0.4%, CaO: 20~
45%, MgO: 6~13%, Fe 2 O 3: 0~12
The iron-based enamel glaze according to any one of claims 1 to 4, having a composition of TiO ₂ : 0.2 to 1.0%. 6. When enamelling an iron-based material, the iron-based enamel glaze according to any one of claims 1 to 5 is used as a lower glaze, and the glaze is applied to the surface of the iron-based material. After firing to form a lower coating layer, the lower coating layer further has an average particle diameter in the range of 15 to 40 μm and an average particle diameter smaller than that of the iron-based enamel glaze. The enamel glaze prepared in large particles is applied as an upper glaze and fired to form an upper coating layer, so that the iron-based material is covered with a coating layer consisting of two upper and lower layers. A method for producing an iron-based enameled product characterized by the following. 7. The enamel glaze used as the top glaze,
SiO ₂ : 28 to 60% by weight, B
₂ O ₃ : 4 to 27%, Al ₂ O ₃ : _{3 to} 14%, Na _{2
O: 6~20%, K 2 O} : 0~9%, CaF 2: 0~5
%, BaO: 1 to 12%, CaO: 0 to 7%, Ti
_{O 2: 0~20%, ZrO 2} : relative frit 100 parts by weight of 0-10% having a composition, by blending 2-10 parts by weight of the clay, by mixing pulverized claim is prepared 6 3. A method for producing an iron-based enamel product according to item 1. 8. The firing of the enamel glaze used as the upper glaze is performed by employing a firing temperature lower than the firing temperature of the iron-based enamel glaze used as the lower glaze. 7. The method for producing an iron-based enameled product according to any one of items 7 to 7. 9. The method for producing an iron-based enameled product according to claim 6, wherein the iron-based material is a cast iron casting.