Flotation of Chromite as Pre-Treatment of Olivine Before Carbonation for CO2 Sequestration

Background and Objective: For the sake of optimal beneficiation of the products formed in the chemical sequestration of CO2 on silicates, extraction of the chromite has been carried out prior to carbonation, by flotation in a lab-scale column. Method: Industrial-grade olivine and serpentine were tested. Flow conditions e.g. gas flow rate, stirring, particle diameter of silicates, and physicochemical considerations (composition if the electrolyte solution) have been examined to optimize the separation efficiency in terms of chromite recovery or enrichment factor. Result: The high performance observed with chromite-enriched olivine allows a multistage flotation process from low-chromite minerals blends to be designed. Conclusion: The lower performance with native olivine was attributed to the existence of mixed chromite-silicate particles.