Isotope-tagging atmosphere to characterize carbonate ore decomposition reaction in carbon dioxide

Abstract

This study utilizes a combination of micro fluidized bed analysis technology and isotope-tagging methodology to investigate the decomposition of carbonate ores in CO₂ atmospheres. Utilizing the decomposition of magnesite in an atmosphere containing ¹³CO₂ as a case study, the reaction behavior and kinetics were investigated using a micro fluidized bed reaction analyzer (MFBRA). The results reveal that ¹³CO₂ in the atmosphere hinders the decomposition process, thereby increasing the time required for complete decomposition. The activation energy was observed to increase with the concentration of ¹³CO₂ in the reaction atmosphere. Compared to the results obtained from thermogravimetric analysis (TG), the activation energy and pre-exponential factor values determined by the MFBRA are lower. Due to the excessive suppression caused by the accumulation of product gas within the sample crucible, the apparent activation energy calculated based on TG data was overestimated, particularly in atmospheres containing the product gas CO₂. The MFBRA, operating in an environment characterized by essentially eliminated external gas diffusion, extensive gas–solid mixing, and high rates of mass and heat transfer, has proven to be highly capable of accurately determining the kinetics of carbonate ore decomposition in CO₂-rich atmospheres. This study provides a straightforward and reliable method for elucidating the reaction characteristics and kinetics of carbonate ore decomposition in atmosphere of CO₂.