JPS6029666B2 - Manufacturing method for basic magkuro ribbon bricks - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing basic ribbon bricks having excellent spalling resistance and corrosion resistance.

Basic ribbon bricks are Kamefu and sintered maguku.

Because it is sintered at a high temperature of 1,700 degrees or more using clinker as a raw material, it is dense, has high hot strength, and has high corrosion resistance. , it has poor spalling resistance like magnesia brick. Therefore, when used as slag line in an outside-furnace refining furnace, flaking occurs first due to thermal shock, and its high corrosion resistance cannot be fully demonstrated, so its uses are limited. The present invention improves the spalling resistance, which is the biggest weakness of ribbon bricks, by adding coarse particles of chromite to ribbon bricks.

Among the raw materials for basic bricks, Ku. Chromium ore is a raw material with a small coefficient of thermal expansion, and when macroscopic direct bond bricks are observed microscopically, voids are often seen around chromium ore. The method of improving the spalling resistance of ribbon bricks according to the present invention utilizes these properties of chromite.

Conventional ribbon bricks have a homogeneous and delicate brick structure due to the single use of maguro clinker, but the product of the present invention has The organization was intentionally made heterogeneous.

However, if the brick structure is made too heterogeneous and the connective tissue of the brick is destroyed, the corrosion resistance will deteriorate, so it is necessary to control this heterogeneity. In other words, if a large amount of chromium ore is distributed to the extent that the voids around individual chromium ores communicate with each other, problems will occur in terms of corrosion resistance and strength. In the product of the present invention, in order to add as much chromite as possible, which has a small coefficient of thermal expansion, and to minimize the destruction of the connective tissue of the bricks, the particle size of chromium is set to 5-3 and the amount added is 5-2.
It is regulated at 0%.

By doing so, a dense and strong brick structure is formed, and it is possible to improve the spalling resistance without impairing the high corrosion resistance that is a characteristic of ribbon brick. 0
A test example is shown below.

As a method for adding chromite, first, in order to minimize the destruction of the connective tissue of ribbon bricks, the particle size of chromite added was set at 5 to 3, and the amount of addition was investigated.

Using the open melted maguro clinker shown in Table 1 and chromite from Africa as raw materials,
.

A in Table 2 corresponds to the conventionally common pound brick. The reason why the content of 5-3 ribs of chromite is limited to 20% or less is that if 20% or more is added, the brick structure will deteriorate and the high corrosion resistance, which is a characteristic of ribbon-bonded bricks, will not be maintained.

Table 3 shows the quality of the bricks produced in five different combinations: A, B, C, D, and E.

Compared to the conventional ribbon brick A, all of B, C, D, and E have improved spalling resistance, and in particular, E with 20% chromite added is significantly improved. Also,
The corrosion resistance of B, C, D, and E is almost comparable to that of conventional ribbon bricks. Table 1 Chemical composition of raw materials
(Weight *)Table 2
Case (1) Table 3 Brick quality (1) *Normal size One side heating-air cooling Repeated ** A 20 x 20 x 150 sample was immersed in 1650℃ molten slag (0a/Si02=1) for 30 minutes. Port loss index when calculating the eclipse rate and setting A to 100 Next, in order to check whether the particle size of the chromium ore to be added is appropriate for 5 to 3 jobs, limit the amount added to 20% and express the particle size to be added. We considered the following.

The trial manufacturing method used the raw materials shown in Table 1 in the same manner as A, C, D, and E described above, and was based on the general method for manufacturing magcro direct bond bricks. Table 5 shows the quality of the bricks prototyped using the F and G combinations.

Both F and G have good spalling resistance when compared to conventional product A, but are not as good as E in Table 3, and the corrosion resistance is slightly deteriorated. In other words, this result shows that by reducing the particle size of chromite, the number of chromite increased and the number of locations where the connective tissue of the ribbon bricks was destroyed increased. Furthermore, it has been shown that when adding a certain amount of chromite to improve spalling resistance, it is effective to set the particle size of chromite on the 5 to 3 side.

Table 4 Mixture (2) Table 5 Brick quality '2) The product of the invention invented as described above is suitable for use in AOD furnaces, VOD pots, ASEA-SKF pots, etc., which are operated at particularly high temperatures.
Excellent as a refractory lining for main damaged areas of VAD pots, DH furnaces, RH furnaces, etc.

For example, when the E bricks in Tables 4 and 5 were tested with the slag line of an ASEA-SKF pot and the blade of an AOD furnace, they showed less spalling damage, and each had a life of approximately 20% compared to the case of the subordinate glue bond bricks. Achieved up.

Claims (1)

[Claims] 1 Electro-fused or sintered magcro clinker with a particle size of 5~
A method for producing basic magurobond bricks by kneading, molding, and sintering to which 5 to 20% of 3 mm chromite is added.