Influence of Pyrophyllite on Durability of Al_2O_3-SiC-C System Bricks

摘要

An iron ladle used for hot metal pretreatment is an open structure with no lid on the ceiling part and also because acceptance and discharging of hot metal are repeated, temperature variation during operation is extremely great. Therefore, for reason corresponding to the embrittlement due to long term repetition of heating and cooling, Al_2O_3-SiO_2- SiC-C system bricks, which are superior in thermal spalling resistance properties, are popular for application to the work lining. According to past researche, Morimoto et al. reported that a brick with carbon fortified Roseki raw materials (Japanese name of a refractory raw material composed primarily of Pyrophyllite mineral, the same shall apply hereafter) was applied to a iron ladle and could realize service life extension and cost reduction, resulting in a good result. And also Kitani et al. reported that improvement of spalling resistance and extension of service life were realized by adding a special carbon, which is a high-quality pitch system caking coal having a self-sintering property due to heat-treatment at 450°C, in Al_2O_3-SiC-C system bricks used for installation in the center of iron ladle bottom bricks where exfoliation by thermal and mechanical spalling have become the main damage factor.