Effect of CO2 Gasification on High‐Temperature Characteristics of Iron Coke: In Situ Compressive Strength

Abstract

High‐temperature compressive strength of the ironmaking burden is crucial for evaluating its comprehensive performance. Iron coke is one of the novels and widely studied low‐carbon ironmaking charges. This study investigates the in situ high‐temperature compressive strength of iron coke after CO2 gasification. The mass loss, morphology, and micromorphology of the iron coke in the CO2 gasification roasting process are studied to clarify the high‐temperature compressive strength evolution mechanism. The results show that the reactivity of iron coke is inversely correlated to carbonization temperature. The high‐temperature compressive strength is mainly influenced by the coke matrix in the inner of the iron coke. Upon increasing the CO2 gasification roasting temperature, the density of the coke matrix in the iron coke decreases gradually, while the internal voids in the iron coke increase, resulting in decreased high‐temperature compressive strength. The initial compressive strength of iron coke with 40% iron ore content reaches >3800 N, while it decreases to <2000 N when roasted at 1150 °C for 30 min under a CO2 atmosphere. The high‐temperature compressive strength of iron coke with 40% iron ore content decreases around 40% when the CO2 gasification roasting period increases from 30 to 90 min at 1100 °C.