Metallurgical Properties of Biocarbon in Ferroalloy Production-A Review

The significant volume of CO₂ emissions contributes to global warming, which has drawn substantial attention. Metallurgical processes contribute to around 30% of these emissions, with ferroalloy smelting alone equivalent to the collective mean CO₂ emissions from 11.8 million people. Biocarbon emerges as a promising substitute for fossil reductants, and its research and industrial application have the potential to significantly curtail emissions on a relatively short time scale. As a result, extensive research has been conducted on biobased carbon materials and their practical utilization in metal production processes. In this review, an overview of the methodologies employed to assess the CO₂ reactivity, electrical conductivity, reactivity toward slag and SiO, and mechanical strength is illustrated. The impact of characterizations on its behavior within furnaces is concluded. Furthermore, the ongoing efforts to substitute traditional fuels with these environmentally friendly materials in the sintering process are introduced. The metallurgical properties of biocarbon are closely related to its chemical composition and physical characteristics, such as porosity, surface area, and internal structure. It has higher CO₂ reactivity, lower electrical conductivity, higher SiO reactivity, and lower mechanical strength than conventional coke. Some of the drawbacks can be addressed through techniques such as densification, pyrolysis, carbonization, and agglomeration, effectively mitigating these limitations. Additionally, the current application situation on sintering has demonstrated that the substitution of specific coke amounts with biobased reductants in the ore agglomeration process can save energy. The incorporation of biocarbon in metallurgy is a feasible and potential way to reduce CO₂ emissions, and this work deserves a valuable and significant endeavor.