The main methods of steel smelting in the world are converters, electric arc furnaces and open hearth furnaces. Open hearth furnaces are almost abandoned, converters steel smelting accounts for 70% of steel output. Electric arc furnaces steel making is growing continuously, with the increase of waste steel resource and the mature of electric arc furnace technique, electric arc furnace steel smelting ratio is increasing, and the output proportion is over 40% in developed countries.
Refractory Material For Converter Steel Making
Converter’s raw material is steel liquid and waste steel, after decarburization treatment such as scorification, oxygen blowing and so on, steel liquid which can meet the requirement is obtained. The service life of furnace linings varies from the types of steel smelted. For instance, if only carbon steel is smelted, the smelting temperature is relatively low, slag composition is relatively stable, so the service life of furnace lining is correspondingly higher. If there are dephosphorization treatment, the service life will be much shorter.
In recent years, converter smelting technique has development rapidly, especially with the development of converter combined blowing craft, i.e., settling purging plug bricks at the bottom of converter for blowing nitrogen, carbon dioxide, argon or oxygen into the furnace, which can strengthen molten bath stirring, improve smelting reaction, shorten smelting time, enhance steel liquid quality and curtail steel making cost.
But combined blowing technique will also accelerate the corrosion to furnace lining refractory materials, and different parts of converter will suffer different types of corrosion.
At furnace crown, the main damages are slag erosion, current fluxing, magnesia carbon bricks oxidation and mechanical abrasion during cleaning. So high oxidation resistant and high strength magnesia carbon bricks should be used at furnace crown.
For converter trunnion zone, where suffers severe slag corrosion, airflow fluxing oxidation as well as mechanical stress, and is very difficult for patching, the best quality high strength, high erosion resistant magnesia carbon bricks which contains 16%~18% of carbon should be used.
For slag line part, where mainly suffers slag erosion, high grade corrosion resistant magnesia carbon bricks should be applied.
For material loading side, it should not only endure steel liquid and slag corrosion, but also endure severe impaction and scouring during loading iron liquid and waste steel. So, high corrosion resistant, high thermal shock resistant and high strength magnesia carbon bricks should be used.
For tapping hole, where oxidation, slag corrosion, temperature fluctuation and steel liquid scouring severe, high strength and high oxidation resistant magnesia carbon bricks should be used.
Refractory Material Professional Manufacturer – RS Refractory
Rongsheng kiln refractory manufacturer is a comprehensive enterprise in refractory material industry, high temperature fireproof products cover metallurgy, refractory building materials, electric power, chemical industry, etc. Hot sale products such as ceramic fiber refractory material, refractory bricks, castable, refractory cement, ramming mass and so on are exported to many countries in the world and highly appreciated by customers.
