The domestic converter slag retaining technology is still in its infancy. The relevant application of refractory materials and equipment, and replacement operation technology need to be continuously improved and optimized. At present, the main refractory material problems and deficiencies that restrict the development of this technology are as follows.
The life of the skateboard is relatively low. At present, the material of the domestic converter skateboard is mostly aluminum-zirconium carbon. As the material of the ladle skateboard, it has high strength, good thermal shock resistance, excellent erosion resistance and corrosion resistance; but for the slag blocking technology of the converter skateboard In other words, the service life of the skateboard is relatively low, and it can only be stabilized between 10 and 14 furnaces. Basically, it is replaced once per shift. The number of replacements of the mechanism is relatively frequent. To a certain extent, it cannot meet the needs of the fast-paced steelmaking production of the converter. It also increases the labor intensity of workers.
The life of the tap hole needs to be further improved. The life of the tap hole is one of the important indicators of the converter sliding plate slag retaining technology. The tapping is caused by the frequent direct erosion and violent erosion of high temperature molten steel and high oxidizing slag, and the effect of rapid cold and hot heat. The mouth is easily damaged. The length of its life directly affects the converter smelting cycle, steelmaking productivity and slag retaining effect, which in turn affects the quality of steel. The integrity of the tap hole directly controls the amount of slag in the converter, and has a direct impact on the alloy yield and the next refining process (LF, RH, etc.).
At present, the service life can be stabilized between 90 and 110 furnaces, but it is difficult to break through the bottleneck of higher service life. The core problem is mainly that the joint part of the tap hole and the inner nozzle brick is a flat surface or a composite mouth contact form bonded by fire mud , The contact part is in surface-to-surface contact, and the probability of air infiltration into the contact surface is greater during use. Due to the oxidation, looseness and peeling of the contact surface caused by multiple replacements, especially the contact part between the tap hole and the inner nozzle (end C brick) needs to be used with multiple sets of inner nozzle bricks, the influence of the oxidation and looseness of the contact surface is more obvious , The service time of the C brick at the end of the tapping port has become the key to directly determining the longevity of the tapping port.
