Chemical kinetic modeling and parameter sensitivity analysis for the carbonation of Ca2+ and Mg2+ under ambient conditions

Tahereh Hosseini, Mahdi Daneshpayeh, Cordelia Selomulya, Nawshad Haque, Lian Zhang

Research output: Contribution to journalArticleResearchpeer-review

5 Citations (Scopus)

Abstract

A reaction model was developed to predict kinetic parameters and competition of Mg2+ and Ca2+ ions during carbonation in mild conditions, i.e. ambient temperature and up to 3 atm for the CO2 partial pressure. The experimental carbonation results at different temperatures, Mg2+/Ca2+ ratios, and atmospheric pressure were used to validate and predict the kinetic parameters of individual reactions in the aqueous phase by applying genetic algorithm and reactor modeling. This model showed a good agreement with experimental results, and satisfactorily predicted the competition between Mg2+ and Ca2+ and the formation of magnesian calcite (MgNCa(1-N)CO3). In addition, a sensitivity analysis was conducted based on the validated kinetic model to maximize the precipitation rates of Mg2+ and Ca2+ . It was found that the final yield for magnesian calcite is the highest for the Mg2+/Ca2+  molar ratio of 1, referring to an equal concentration of two cations in the leachate. This suggests the strongest synergy between both cations for their co-precipitation. The optimum ammonia amount used as a pH-swing agent was found to be equal to the amount of ammonia released from the leaching stage in a closed loop leaching-carbonation. This amount of ammonia led to ~ 100% Mg2+ and Ca2+  precipitation along with the highest magnesian calcite precipitation yield.
Original languageEnglish
Pages (from-to)141-152
Number of pages12
JournalHydrometallurgy
Volume167
DOIs
Publication statusPublished - Jan 2017

Keywords

  • Mineral carbonation
  • Kinetic modeling
  • Sensitivity analysis
  • Genetic algorithm
  • Magnesian calcite

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