JPH0144669B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a magnesia carbonaceous brick, particularly a magnesiacarbonaceous brick having excellent oxidation resistance. Magnesia carbon bricks, which are used as lining materials for converters, electric furnaces, and various ladles, have the advantages of magnesia's erosion resistance and carbon's thermal conductivity, but they are mainly composed of carbon. Therefore, it has poor oxidation resistance. For this reason,
Conventionally, various methods of impregnating the bricks with various antioxidants or adding them to brick raw materials have been adopted, but at present, sufficient oxidation resistance has not been obtained. The present invention has been made to solve the above problems, and is a refractory brick for lining mainly composed of magnesia and carbon, in which the particle size of the magnesia serving as the aggregate is 3 mm or less. , which is characterized in that a thermosetting resin is added as a binder, and is characterized in that a uniform slag coat is formed on the brick surface during use. In this invention, the reason why the particle size of the magnesia particles serving as the aggregate is set to 3 mm or less is as follows. That is, as shown in FIG. 1A, the particle size of the coarse magnesia grains 1' in the conventional brick is:
Since the thickness was less than 5 mm, the slag coat 2' on the brick surface was non-uniform. On the other hand, as shown in Figure 1B, if the grain size of the coarse particles of magnesia grains 1 is 3 mm or less, uniform slag cords 2 are formed on the brick surface, so that the oxidation rate of the brick surface during use increases. This is because it is held down by a large cloth. Here, the slag coat is a glass layer formed on the surface of a brick by contact and reaction between the brick, molten steel, and slag. Next, embodiments of the invention will be described. Bricks 1 and 2 of the present invention and Comparative Bricks 3 and 4 having the compositions shown in Table 1 were manufactured, and these bricks were used to line a ladle slag line,
After using 20 charges, the brick was cut and its erosion rate was investigated. These results are shown in Table 2.

【table】

[Table] In Table 1, the particle size distribution of coarse particles is Table 3 A,
As shown in B.

【table】

[Table] In Table 2, the erosion rate is expressed by the following formula, where the thickness of the brick after 20 charges is Am/m and the thickness of the brick before use is Bm/m. Erosion rate = B-A/B x 100 (%) As is clear from Table 2, the present invention bricks 1 and 2
It can be seen that the erosion rate of Brick Bricks is greatly improved compared to Comparative Bricks 3 and 4. As explained above, according to the present invention, by reducing the particle size of the magnesia clinker used as aggregate to 3 mm or less, it is possible to form a uniform slag coat on the brick surface. This has the extremely useful effect of being able to solve the problem of poor oxidation resistance, which has been considered the biggest drawback of solid bricks.

[Brief explanation of drawings]

FIG. 1A is a sectional view showing a slag coat formed on the surface of a conventional magnesia carbon brick, and FIG. 1B is a sectional view showing a slag coat formed on the surface of the magnesia carbon brick of the present invention. . In the drawings, 1,1'...magnesia grains, 2,2'...slag coat.

Claims (1)

[Claims] 1. A refractory brick for lining containing magnesia and carbon as the main components, characterized in that the magnesia serving as the aggregate has a particle size of 3 mm or less, and a thermosetting resin is added as a binder.
A magnesia carbon brick that forms a uniform slag coat on the brick surface during use.