JPS61286270A - Flow-in monolithic refractories for ladle slag line - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a refractory for lining a ladle slag line, which has excellent corrosion resistance, spalling resistance, and volume stability.

[Conventional technology]

In recent years, ladle lining refractories have generally been constructed using monolithic refractories from the viewpoint of energy and labor savings.
In addition, the pouring method has become widely used because it allows so-called refill construction, which allows construction to be performed while leaving the old material, and has a large effect on reducing the cost of furnace materials.

As the pouring material, for example, semizircon, alumina, basic materials, etc. are used.

[Problem that the invention seeks to solve]

However, most of these materials are currently limited to construction of ladle molten steel parts, and are not currently applied to lining parts of slag lines that are subject to severe erosion.

The reason for this is that semizircon materials require the use of a certain amount of expandable raw materials such as waxite and silica as aggregates to suppress the occurrence of cracks.
One example of this is that the 2-rich component weakens the resistance to basic slag.

On the other hand, at present, alumina and basic properties are not applied due to the occurrence of thermal and structural spalling phenomena.

For this reason, even now that ladle lining with poured material is being put into practical use, fired zircon bricks are still used for the slag line.

An object of the present invention is to provide a zircon-based pouring material that is excellent in corrosion resistance and spalling resistance and can be used as a lining material for a ladle slag line.

[Means for solving problems]

The zircon-based pouring material of the present invention has zircon coarse particles or fused A12 oa-Zr02 in the particle size structure of the aggregate.
-5-ZrO2-based coarse particles (electrofused AZS-based coarse refined coarse particles or a combination of these coarse particles are +1 20 in the Tsuru particle size range)
~50% by weight.

The relationship between these two types of aggregate particle size structure and natural flowability is shown in Figure 1. Particle size range +1fi, 1~0.21m, 0
．． When divided into 21 to 0 Tsuru, it shows good fluidity when it is within the area indicated by the diagonal lines in the same figure, and if it is less than 20% by weight or more than 50% by weight in the +1fi particle size range, the natural fluidity during construction will be significantly deteriorated, and it is preferable. do not have.

Although zircon coarse particles alone can be used as aggregate, electro-fused AZS coarse refined coarse particles have a much denser structure than ordinary zircon coarse particles. By doing so, high corrosion resistance can be obtained. Furthermore, the effect of promoting sintering and preventing slag infiltration can be obtained due to the influence of the appropriate amount of Al1OA acid component present in the electrofused AZS coarse particles.

However, the amount of the electrofused AZS coarse particles is set to be 30% by weight or less, and if it is used in excess of this amount, the Al1 oa acid component will be excessive, and corrosion resistance will not improve, but will tend to deteriorate. Zircon sand, zircon flour, etc. are used for the fine powder part of 1fi or less.

As the flocculant, it is preferable to use alumina cement containing 80% by weight or more of the ^1203 component. Al
The use of a general alumina cement containing about 54% by weight of 1 OA acid component is not preferred from the viewpoint of corrosion resistance and explosion resistance due to the influence of a large amount of CaO component.

As for the amount of alumina cement added, if it is less than 2% by weight, it will not be possible to develop sufficient strength as a construction body, and if it is more than 5% by weight, it is unfavorable in terms of corrosion resistance and explosion resistance, so it should be 2 to 5% by weight. Should.

As the dispersant, it is preferable to use a water-soluble polymer compound whose main component is a derivative of carboxylic acid. Conventionally, inorganic substances such as alkali metal phosphates have been generally used as dispersants, but the impact on explosion resistance and dissociation of zircon when alumina cement is used as a coagulant has been investigated. Considering this, an organic dispersant is preferable. If the amount of the dispersant added is less than 0.03% by weight, a proper dispersion effect cannot be obtained, and if it is more than 0.5% by weight, the dispersion effect converges, so it is 0.03 to 0. .5% by weight is preferred.

The minimum amount of clay needed to provide fluidity is sufficient; if it is less than 2% by weight, sufficient fluidity for construction cannot be obtained, and if it is more than 5% by weight, there will be problems in terms of corrosion resistance and explosion resistance. Therefore, it is preferably 2 to 5% by weight. In addition to clay, ultrafine silica powder and ultrafine zircon powder can also be used to impart fluidity.

〔Example〕

A pouring material was prepared using coarse particles and a flocculant having the composition and properties shown in Tables 1 and 2, respectively. Table 3 shows the formulation and characteristics of the zircon casting material of the present invention as an example, together with comparative examples.

Table 4 shows the physical property values of Example (Blend 2) and Comparative Example (Blend 8).

The pouring material shown in the embodiment (formulation 2) of the present invention is applied to the slag line portion 1 above the molten steel section lining 2 formed with the conventional pouring material in the 185T molten steel ladle shown in FIG. A test was conducted using a slag formed to a thickness of 180 fi and having the composition shown in Table 5.

Table 6 shows the applicable materials for the slag line and the performance of the furnace material for the ladle.

By applying the pouring material of the present invention to the slag line, it was possible to achieve a greater reduction in the furnace material consumption rate and unit cost than in the past.

Table 1 Table 2 Table 4 Table 5 Table 6 [Effects of the Invention] According to the present invention, the lining of the ladle slag line part can be formed with a poured material in the same way as the conventional molten steel part. , it is possible to further reduce the unit cost of furnace materials.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between the particle size distribution of coarse particles and natural fluidity in the present invention, and FIG. 2 shows an example in which the cast refractory of the present invention is applied to an actual ladle.

Claims (1)

[Claims] 1. The coarse grain area of 1 mm or more is zircon coarse particles alone or zircon coarse particles and electrofused Al_2O_3-ZrO_2-Si
Contains 20 to 50% by weight of O_2-based coarse particles, the remainder being one or more of zircon sand and zircon flour, clay,
A cast monolithic refractory for ladle slag lines consisting of one or more of ultrafine silica powder, ultrafine zircon powder, a dispersant, a flocculant, etc.