Abstract
In this study, through thermodynamic calculation, the possible reactions of carbon composite bricks in a high-temperature water vapor environment were analyzed. The morphology of carbon composite bricks after water vapor erosion was investigated through a water vapor oxidation experiment. In addition, a damage investigation was carried out on a blast furnace using hydrogen-rich gas smelting. During the period, a green-white phase with a thickness of 150 mm–200 mm was found inside the carbon composite brick in the taphole area. The carbon bricks in this area were sampled, and XRD, chemical analysis, and SEM–EDS detection were carried out. The test results show that there is blast furnace slag erosion and harmful element Zn erosion in carbon composite bricks. The erosion of harmful elements caused the expansion and ring cracking of carbon composite bricks, resulting in further slag erosion, which eventually led to the macroscopic slag phase erosion in the taphole area. The service life of carbon composite bricks can be effectively improved by optimizing the structure of carbon composite bricks, reducing the number of pores, optimizing the pore structure, and promoting the formation of a slag-rich protective layer on the hot surface of carbon composite bricks by improving the structure of blast furnace slag system.