JP4598328B2 - Method of kneading irregular refractories - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, when kneading by adding water to the irregular-sized refractory raw material, increasing the fluidity of the irregular-sized refractory material, kneading the irregular-sized refractory to improve the quality of the irregular-sized refractory performing kneading of low moisture Regarding the method.
[0002]
[Prior art]
Conventionally, refining furnaces such as converters and electric furnaces, and ladles, tundishes, firewood, etc. used for transporting and storing molten iron are relatively easy to manufacture and construct, and are easy to mechanize (automate) construction. For this reason, amorphous refractories are used. This amorphous refractory can improve the durability by improving the kind and composition of the amorphous refractory raw material, and its application range is expanded.
The irregular refractory raw material is prepared by mixing the aggregates adjusted in particle size in consideration of the filling density when filling the construction body and the like, and various types of powder additives in advance in a dry state. A dispersant is added to the regular refractory raw material, and further, water is added and kneading is performed for a predetermined time.
Then, by kneading the amorphous refractory raw material and water, the surface of the fine particles contained in the amorphous refractory raw material is charged, and the added dispersant dissolves in water and is ionized to be included in the amorphous refractory raw material. It is adsorbed on the surface of the fine powder particles to activate the charging of the fine particles to suppress agglomeration and enhance the fluidity (flow value) of the amorphous refractory.
However, depending on the water added, the flowability of the amorphous refractory cannot be increased, and when a large amount of water is added and kneaded, the fluidity of the amorphous refractory is a hindrance to filling during construction. I am trying not to become.
When the amount of water in the amorphous refractory increases, when the amorphous refractory is dried after filling, the porosity increases, strength decreases, water vapor separation occurs during drying, etc. Abrasion resistance is reduced.
As a countermeasure against this, as described in JP-A-8-239276, a dispersant is dissolved in water in advance to form a mixed solution, and this mixed solution and an irregular refractory raw material are kneaded, so that A construction method for an amorphous refractory having a high strength is disclosed by rapidly dispersing a regular refractory raw material to produce an amorphous refractory having a uniform composition.
[0003]
[Problems to be solved by the invention]
However, in the method described in JP-A-8-239276, since the added water contains multivalent ions such as Ca and Mg, the surface potential of the fine particles contained in the amorphous refractory raw material is lowered. And easily aggregate.
In addition, in order to improve the cohesiveness due to the surface potential of the fine particles, it is necessary to increase the addition amount of the dispersant and water, which increases the production cost of the amorphous refractory.
Furthermore, the increase in the amount of dispersant and water added reduces the strength of the amorphous refractory, increases the porosity, and decreases the corrosion resistance, wear resistance, and the like. Furthermore, the life of a refining furnace lined with an indeterminate refractory, a transporting container for molten iron, and the like are shortened, and the use cost of the refractory increases.
[0004]
The present invention has been made in view of such circumstances, and the fluidity of the amorphous refractory raw material can be improved even if the amount of water added when kneading the amorphous refractory raw material is reduced. to lower the porosity and uniformly mixed, aims to enhance the corrosion resistance and abrasion resistance of monolithic refractories, provides a kneading method indefinite shaped refractory material can reduce the cost of using refractory And
[0005]
[Means for Solving the Problems]
In the kneading method of the irregular-sized refractory of the present invention along the object, irregular shaped refractory containing and aggregate having a coarse grain of at least the particle size 1 to 5 mm, and a fine alumina powder or silica powder of particle size less than is 0.075mm A dispersant is added to the raw material, and water having an electric conductivity of 5000 μs / m or less is added and kneaded.
In this way, reduced multivalent ions of Ca or Mg or the like contained in the water, to prevent the surface potential of the fine particles contained in the irregular-sized refractory raw material is neutralized, the surface potential of the particles is reduced can be suppressed, to prevent aggregation of the fine particles, it is possible to increase the flow value of the irregular-sized refractory raw material after kneading.
When the electric conductivity exceeds 5000 μs / m, the surface potential of the fine particles is neutralized by polyvalent ions such as Ca and Mg contained in water, the function of the dispersant is lowered, and the fine particles are likely to aggregate, which is indefinite. Uniformity at the time of kneading of the shaped refractory raw material is hindered.
The lower the electrical conductivity, the greater the effect. Therefore, it is preferable to use water of 2000 μs / m or less, and more preferable results are obtained when water of 500 μs / m or less is used.
[0006]
[0007]
Further, in the kneading method for irregular-sized refractory according to the present invention, water added to the monolithic refractory raw material can also be used alkali ion water obtained by electrolysis.
Thus, a multivalent ion such as Ca and Mg were removed by electrolytic treatment, since water containing OH groups, the molecular size of water smaller can easily wet the surface of the fine particles, the irregular shaped refractory raw material The fluidity can be improved.
[0008]
Further, in the kneading method for irregular-sized refractory according to the present invention, water added to the monolithic refractory raw material can also be used pure water.
Thus, the use of multi-valent ions were removed water, such as Ca and Mg in kneading, suppressing the dispersion of the polyvalent dispersant by ions is inhibited, well kneading indefinite shaped refractory raw material It can be carried out.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
Figure 1 is a graph chart showing the relationship water amount and flow value to be added during kneading of the kneading method indefinite shaped refractory according to an embodiment, FIG. 2 which represents a relationship between the addition amount of water and corrosion resistance index of the present invention FIG. 3 is a graph showing the relationship between the type of added water and the steam explosion index during drying, and FIG. 4 is a graph showing the relationship between the type of added water and the dissolution rate.
The amorphous refractory is added to the refractory raw material that is premixed with fine particles such as alumina fine powder, silica fine powder, hardeners such as cement, phosphate, silicate, etc. Furthermore, it is manufactured by adding water and kneading.
However, when a dispersant and water are added to an amorphous refractory raw material and kneaded, polyvalent ions such as Ca and Mg contained in the water greatly affect the fluidity of the amorphous refractory produced by kneading. I found out that
It has also been found that this fluidity shows the same tendency when kneaded using a mixed liquid in which a dispersant is mixed with water in advance.
[0010]
Therefore, as the kneading method indefinite shaped refractory according to an embodiment of the present invention, as shown in FIG. 1, as the water to be added to the monolithic refractory raw material, a hardness component in the filtration membrane Ca, Mg, or the like removed The electrical conductivity is, for example, 5000 μs / m or less by removing Ca, Mg or the like by pure water having a value measured by a commonly used electrical conductivity meter of 5000 μs / m or less, or by electrolytic treatment. The alkaline ionized water was used, and after adding a dispersant, each was added to an amorphous refractory raw material containing a curing agent and kneaded for 3 minutes, and each flow value (fluidity) was investigated.
As a result, compared with the case where the conventional additive water (tap water) is mixed with a dispersant at the same time and used as added water, the amount of water added is in the range of 6.0 to 6.5 % by mass. Although there is no difference in the flow value, when the amount of water to be added is less than 6.0 % by mass , when using conventional water purification, the flow value decreases rapidly, and the filling property of the irregular refractory is impaired. It was found that workability and construction quality were affected.
On the other hand, when using pure water from which Ca, Mg, etc., which are hardness components, or alkali ion water not containing hardness components, is used, the flow of the kneaded amorphous refractory even if the moisture content is as low as 5.5 % by mass. The value could be maintained in a high region of 210 to 200 mm, and this tendency did not change even when the amount of water was 5.0 % by mass , and the filling property of the amorphous refractory was good.
Therefore, workability is good, the porosity of the construction body can be reduced, and wear resistance and the like can be improved.
In particular, as shown in FIG. 2, assuming that the corrosion resistance index of the amorphous refractory when the moisture content is 6 % by mass is 100, the amorphous refractory when the moisture content is 5 % by mass has a corrosion resistance index. It can be significantly reduced to 85 to 90, corrosion resistance is improved, the life of a smelting furnace, a ladle for transportation, a bowl, etc. can be extended, and the refractory cost can be reduced.
[0011]
Fine particles such as alumina fine powder and silica fine powder contained in the irregular refractory raw material are charged on the surface of the fine particles, and the fine particles repel each other, increasing the dispersibility of the irregular refractory raw material. By using pure water having an electric conductivity of 5000 μs / m or less from which polyvalent ions such as Mg are removed, the surface potential of the charged fine particles is neutralized by polyvalent ions such as Ca and Mg. It can suppress and can improve the dispersibility of the fine particles in the amorphous refractory raw material.
Furthermore, the dispersing agent when mixed with water has the effect of charging the above-mentioned fine particles, activating the surface of the fine particles, and further improving the dispersibility.
In order to make this dispersant function normally, fine particles in the amorphous refractory raw material are suppressed by suppressing neutralization of the charge of the dispersant by polyvalent ions such as Ca and Mg contained in water. It is presumed that the dispersibility of can be further increased.
Furthermore, since alkaline ionized water has removed polyvalent ions such as Ca and Mg by electrolytic treatment, it suppresses neutralization of the surface potential of charged fine particles by polyvalent ions such as Ca and Mg. The dispersibility of the fine particles can be improved.
In addition, since water containing OH groups is used, the surface of fine particles such as alumina fine powder and silica fine powder contained in the amorphous refractory raw material is charged in order to make the surface of the fine particles wet easily by reducing the molecular diameter of water. As a result, the repulsion between the fine particles and the fine particles can be activated and the dispersibility can be further improved.
In addition, a dispersant mixed with pure water or alkaline ionized water from which polyvalent ions such as Ca and Mg are removed promotes the charging of the fine particles, and the surface of the fine particles is activated to increase the dispersibility. It is assumed that it is possible.
[0012]
The aggregate used as the amorphous refractory material can be any of basic refractory material, neutral refractory material, and acidic refractory material. For example, alumina, magnesia, spinel, calcia, titania, zirconia, silica Quality, waxy stone quality, silicon carbide quality, chamotte quality, dolomite quality, etc. The particle size of the aggregates of these compositions should have an average particle size of 5 mm or less in order to obtain a homogeneous construction body Furthermore, it is preferable to use a mixture of coarse particles of 1 to 5 mm, medium particles of less than 0.075 to 1 mm, and fine particles of less than 0.075 mm so that a good packing density can be obtained.
In addition to the above-mentioned aggregates, coarse aggregates of 6 to 100 mm can also be blended, and in addition to this, the effects of preventing cracks, peeling, etc. are manifested by blending fibers, metal wires, etc. it can.
Furthermore, the hardener is most preferably alumina cement, but is not limited to this, and for example, one or two or more selected from sodium silicate, silica sol, alumina sol, aluminum phosphate, aluminum lactate, etc. are blended into the aggregate. Can be used.
In addition to this curing agent, a curing regulator can be added as necessary to obtain an appropriate usable time. Examples of the curing regulator include boric acid, oxalic acid, citric acid, gluconic acid, boric acid. One kind or two or more kinds of ammonium, sodium ultrapolyphosphate, lithium carbonate and the like can be used in the aggregate.
[0013]
Dispersants added to amorphous refractory raw materials include sodium tripolyphosphate, sodium hexametaphosphate, acid hexametaphosphate soda, polyacrylic acid soda, sulfonic acid soda, nastalene sulfonic acid soda, lignin sulfonic acid soda, ultrapolyphosphate soda, One type or two or more types of sodium carbonate, sodium borate, sodium citrate, tartrate, and the like can be added.
[0014]
An irregular shape formed by adding 5 to 5.5 % by mass of this amorphous refractory raw material with 5 to 5.5 % by mass of a curing agent, a curing modifier, pure water to which a dispersant has been added in advance, or alkaline ionized water that has been subjected to electrolytic treatment. The refractory is poured quickly into the frame surrounding the damaged part while applying vibration with a vibrator to repair the damaged part, or poured into a mold of a predetermined size while vibrating with a vibrator. An irregular refractory block is manufactured, and this block is lined on the construction body.
[0015]
【Example】
Next, examples of the method for kneading the irregular refractory according to the present invention will be described.
A dispersant is added to an irregular refractory raw material in which 2 % by mass of alumina cement as a hardener is blended in an aggregate containing 20 % by mass of alumina and containing 20 % by mass of fine particles, and the type of water used for kneading is changed. Kneading was performed to produce an irregular refractory block.
Then, when the steam explosion occurrence index using conventional tap water when the block is dried is assumed to be 1, the steam explosion occurrence index is shown in FIG. 3, and the irregular refractory block is made of molten steel. The result of investigating the rate of erosion when used in a ladle for conveyance is shown in FIG.
The index of occurrence of water vapor explosion is such that when pure water is used for kneading and when alkaline ionized water is used for kneading, the amount of added water is less than 5.5 % by mass , which hinders the pouring work. A flow value with no water vapor was obtained, and when drying at a temperature of 120 to 900 ° C., no steam explosion occurred and good results were obtained.
In contrast, in the conventional method using tap water, a flow value that does not hinder the construction was obtained by adding 6 % by mass or more of water during kneading, but at a temperature of 120 to 900 ° C. Steam explosion occurred during the drying of the.
Further, when pure water was used for kneading and when alkaline ionized water was used for kneading, the erosion rates were as good as 0.32 mm / ch (charge) and 0.31 mm / ch (charge), respectively. However, in the case of using tap water, it was as bad as 0.37 mm / ch (charge).
[0016]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and all changes in conditions and the like that do not depart from the gist are within the scope of the present invention.
For example, pure water can be produced using an ion exchange treatment, a distillation treatment, etc., in addition to removing Ca, Mg, etc., which are hardness components with a filtration membrane.
Furthermore, the alkali ion water can use what was manufactured by electrolyzing using an electrolytic vessel.
[0017]
【The invention's effect】
In the kneading method of claim 1-3 irregular shaped refractory according to irregular-sized refractory raw material, the electrical conductivity so kneaded with the addition of less water 5000μs / m, when kneaded monolithic refractory material The amount of water to be added is reduced to increase the fluidity (flow value) of the amorphous refractory raw material, facilitating filling work, making the amorphous refractory uniform composition and lowering the porosity, and the amorphous refractory The corrosion resistance and wear resistance of the refractory can be reduced, and the use cost of the refractory can be reduced.
[0018]
[0019]
In the kneading method of claim 2 irregular shaped refractory according, the water added to the monolithic refractory raw material, since an alkali ion water obtained by electrolysis, can easily wet the surface of the fine particles, the irregular shaped refractory flowable Can be improved, the composition can be made uniform, the porosity can be lowered, and the corrosion resistance and wear resistance can be further increased.
[0020]
In the kneading method of claim 3 irregular-sized refractory according, water added to the monolithic refractory raw material, since use of pure water, can lower the porosity in the uniform composition, the corrosion resistance and abrasion resistance Can be increased.
[Brief description of the drawings]
1 is a graph showing the relationship between water amount and flow value during the kneading of the kneading method of indefinite shaped refractory according to an embodiment of the present invention.
FIG. 2 is a graph showing the relationship between the amount of added water and the corrosion resistance index.
FIG. 3 is a graph showing the relationship between the type of added water and the steam explosion index during drying.
FIG. 4 is a graph showing the relationship between the type of added water and the dissolution rate.

Claims (3)

And aggregate at least the particle size has a coarse grain of 1 to 5 mm, particle size and adding a dispersant to the irregular-sized refractory raw material comprising alumina fines or fine silica powder of less than 0.075 mm, the electric conductivity of the following 5000μs / m kneading method indefinite shaped refractory which comprises kneading by adding water. In the kneading method of claim 1 irregular-sized refractory according, water added to the monolithic refractories ingredients, kneading method indefinite shaped refractory, characterized in that an alkali ion water obtained by electrolysis. In the kneading method of claim 1 irregular-sized refractory according, water added to the monolithic refractories ingredients, kneading method indefinite shaped refractory which is a pure water.

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