A REVIEW ON THE USAGE OF BIOCHAR AS AN ALTERNATIVE REDUCTANT IN THE PYROMETALLURGICAL TREATMENT OF ORES

Abstract

Carbon emission has increasingly become a topic of the day. Carbothermic reduction processes and energy generating units have for years used generic carbonaceous materials contributing to high carbon pollution. Ongoing investigations are showing good prospects. This paper corroborates a comprehensive review on the potential of biochar as an innovative and sustainable alternative to traditional carbon sources in pyrometallurgical processes, addressing the environmental ithreats caused by fossil fuel use, such as greenhouse gas emissions and global warming, and the urgent need for greener reductants in metallurgical operations. Derived from various biomass sources through pyrolysis, biochar exhibits unique chemical and physical properties that make it a promising reductant in high-temperature metallurgical operations, particularly in ferroalloy production and metal recovery from slags. The review delves into the characterization of biochar, examining its chemical composition, functional groups, and physical attributes such as high surface area, porosity, and thermal stability. These properties contribute to biochar's enhanced reactivity and efficiency in reduction processes. Multiple studies have demonstrated biochar's superiority over conventional reductants like coke and coal in various applications, including ferrosilicon production, copper slag cleaning, and iron ore reduction. Biochar's porous structure facilitates better gas-solid interactions and diffusion of reducing gases, leading to more uniform and complete reduction reactions. Its higher reactivity, lower activation energy, and potential catalytic effects from inherent mineral matter further enhance its performance in pyrometallurgical processes. The review also highlights the environmental benefits of using biochar, a renewable resource, in reducing the carbon footprint of metallurgical operations. However, the effectiveness of biochar can vary depending on its source material and production conditions, necessitating careful selection and potential tailoring for specific applications. Overall, this review underscores the significant potential of biochar to revolutionize pyrometallurgical processes, offering improved efficiency, lower energy consumption, and environmental sustainability in the metallurgical industry. This paper review only wood and woody biomass as well as herbaceous biomass are reviewed and discussed.