How to extend the life of magnesia carbon bricks for slag line?

When the magnesia carbon brick is in contact with molten steel and slag, the slag corrodes the magnesia carbon brick, which results in poor thermal shock stability of the magnesia carbon brick, spalling damage, shortening the service life of the slag line magnesia carbon brick, and affecting the refining production of the LF furnace. In order to prolong the service life of magnesia carbon bricks, the researchers studied the influence of LF furnace slag on the corrosion resistance of magnesia carbon bricks, and explored ways to extend the life of magnesia carbon bricks for LF slag line. Light burned magnesia

Experimental materials and process

Low-iron slag and high-iron slag used in the LF furnace are selected for the experiment, and the composition is shown in the attached table. The magnesia carbon brick is selected from the slag line magnesia carbon brick MT-14 currently used by Angang.

After the researcher made the slag line magnesia-carbon brick into a crucible sample with an inner diameter of ф60mm×50mm and an outer diameter of ф120mm×100mm, the LF low-iron slag and high-iron slag were respectively loaded into the prepared crucible and kept at 1600℃ for 3h , The static crucible method is used to carry out the slag erosion resistance test of magnesia carbon bricks. They grind two kinds of LF furnace slag into 200 mesh fine powder, use thermoplastic phenolic resin as a binder, press it into a cylindrical sample of ф6mm×5mm, and place it on a gasket made of magnesia carbon brick on the slag line. Place it in the refractoriness tester DRH-III to observe the wetting angle of the molten slag and the magnesia carbon brick when the sample reaches the hemispheric temperature to characterize the wettability of the molten slag on the magnesia carbon brick.

Experimental results and analysis

Wetting angle detection. According to the schematic diagram of the wetting angle of the two slags of the LF furnace on the magnesia carbon bricks, the researchers calculated that the LF slag with less iron has a wetting angle of 45° for the magnesia carbon bricks, and the LF slag with more iron can wet the magnesia carbon bricks. The wet angle is 58°. It can be seen that both slags of the LF furnace can wet the magnesia carbon bricks, and the slag with less iron wetting is more obvious, and the erosion of the bricks is more obvious. Therefore, the slag composition of the LF furnace can be adjusted within a certain range, and the wetting angle of the slag to the product can be increased, thereby improving the corrosion resistance of the magnesia carbon brick.