In situ Compressive Strength of Iron Coke in High-temperature Carbonization

Abstract

In this study, the in situ compressive strength of iron coke in high-temperature carbonization was investigated. The high-temperature compressive strengths of iron coke briquettes with 20, 30, and 40% iron ore with carbonization at 700, 800, 900, and 1000°C for 3 h were systematically studied. The mass loss and microstructure of the iron coke during carbonization were also investigated. The results showed that the mass loss increased with the iron ore content from 20 to 40%. The liquid phase content of the slag in iron coke was calculated using FactSage software. Results showed an increased of liquid phase slag content with increasing of carbonization temperature and decreasing of Fe₃O₄ content. Coal coking, iron oxide reduction, pitch volatilization, and CO₂ gasification in the carbonization process could significantly change the micromorphology of iron coke and influence its high-temperature compressive strength. At a carbonization temperature of 900°C, the mass loss of iron coke increased from 27.59 to 30.23% and the high-temperature compressive strength decreased from more than 4200 to 1589 N with an increase in the iron ore content from 20 to 40%. The degradation mechanism of the high-temperature compressive strength of iron coke with 30 and 40% iron ore, and increased carbonization temperature from 800 to 1000°C, was discussed.