Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT) (방사성폐기물학회지)

Korean Radioactive Waste Society (한국방사성폐기물학회)
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Temperature and Concentration Dependencies of Chemical Equilibrium for Reductive Dissolution of Magnetite Using Oxalic Acid

  • Received : 2020.12.30
  • Accepted : 2021.03.15
  • Published : 2021.06.30
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Abstract

Chemical equilibrium calculations for multicomponent aqueous systems involving the reductive dissolution of magnetite (Fe3O4) with oxalic acid (H2C2O4) were performed using the HSC Chemistry® version 9. They were conducted with an aqueous solution model based on the Pitzer's approach of one molality aqueous solution. The change in the amounts and activity coefficients of species and ions involved in the reactions as well as the solution pH at equilibrium was calculated while changing the amounts of raw materials (Fe3O4 and H2C2O4) and the system temperature from 25℃ to 125℃. In particular, the conditions under which Fe3O4 is completely dissolved at high temperatures were determined by varying the raw amount of H2C2O4 and the temperature for a given raw amount of Fe3O4 fed into the aqueous solution. When the raw amount of H2C2O4 added was small for a given raw amount of Fe3O4, no undissolved Fe3O4 was present in the solution and the pH of the solution increased significantly. The formation of ferrous oxalate complex (FeC2O4) was observed. The equilibrium amount of FeC2O4 decreased as the raw amount of H2C2O4 increased.

Keywords

Acknowledgement

This work was supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry and Energy (MOTIE) of the Republic of Korea (No. 20191510301310).

References

  1. C. Kim and H. Kim, "Study on Chemical Decontamination Process Based on Permanganic Acid-Oxalic Acid to Remove Oxide Layer Deposited in Primary System of Nuclear Power Plant", J. Nucl. Fuel Cycle Waste Technol., 17(1), 15-28 (2019). https://doi.org/10.7733/jnfcwt.2019.17.1.15
  2. H. Ocken. Decontamination Handbook, Economic Policy Research Institute Report, TR-112352 (1999).
  3. R. McGrath and J. Cabrera. Nuclear Power Plant Full System Chemical Decontamination Experience Report, Economic Policy Research Institute Report, 21-43, TR-1019230 (2009).
  4. T.A. Beaman and J.L. Smee. Evaluation of the Decontamination of the Reactor Coolant Systems at Maine Yankee and Connecticut Yankee, Economic Policy Research Institute Report, TR-112092 (1999).
  5. D. Well. Recent Chemical Decontamination Experience, Economic Policy Research Institute Report, 3002000555 (2013).
  6. D.H. Lee. Analysis of Basic Requirements for Kori-1 Full System Decontamination, Korea Hydro & Nuclear Power Central Research Institute Report, 2015-50003339-0488TC (2015).
  7. J.Y. Jung, S.Y. Park, H.J. Won, S.B. Kim, W.K. Choi, J.K. Moon, and S.J. Park, "Corrosion Properties of Inconel-600 and 304 Stainless Steel in New Oxidative and Reductive Decontamination Reagent", Met. Mater. Int., 21(4), 678-685 (2015). https://doi.org/10.1007/s12540-015-4572-x
  8. J.K. Moon, S.B. Kim, W.K. Choi, B.S. Choi, D.Y. Chung, and B.K. Seo, "The Status and Prospect of Decommissioning Technology Development at KAERI", J. Nucl. Fuel Cycle Waste Technol., 17(2), 139-165 (2019). https://doi.org/10.7733/jnfcwt.2019.17.2.139
  9. K.S. Pitzer, "Thermodynamics of Electrolytes. I. Theoretical Basis and General Equations", J. Phys. Chem., 77, 268-277 (1973). https://doi.org/10.1021/j100621a026
  10. C.E. Harvie and J.H. Weare, "The Prediction of Mineral Solubilities in Natural Waters: the Na-K-Mg-Ca-Cl-SO4-H2O System From Zero to High Concentration at 25℃", Geochim. Cosmochim. Acta, 44(7), 981-997 (1980). https://doi.org/10.1016/0016-7037(80)90287-2
  11. C.E. Harvie, N. Moller, and J.H. Weare, "The Prediction of Mineral Solubilities in Natural Waters: The Na-K-Mg-Ca-H-Cl-SO4-OH-HCO3-CO3-CO2-H2O System to High Ionic Strengths at 25℃", Geochim. Cosmochim. Acta, 48(4), 723-751 (1984). https://doi.org/10.1016/0016-7037(84)90098-X
  12. B.C. Lee, S.B. Kim, and J.K. Moon, "Equilibrium Calculations for HyBRID Decontamination of Magnetite: Effect of Raw Amount of CuSO4 on Cu2O Formation", Nucl. Eng. Technol., 52(11), 2543-2551 (2020). https://doi.org/10.1016/j.net.2020.04.012
  13. K.S. Pitzer, Thermodynamics, 3rd ed., McGraw-Hill, New York (1995).
  14. K.S. Pitzer, Activity Coefficients in Electrolyte Solutions, 2nd ed., CRC Press, Boca Raton, FL (1979).
  15. J.M. Prausnitz, R.N. Lichtenthaler, and E. Gomes de Azevedo, Molecular Thermodynamics of Fluid- Phase Equilibria, 3rd ed., Pearson Education, London (1999).
  16. J.F. Zemaitis, Jr., D.M. Clark, M. Rafal, and N.C. Scrivner, Handbook of Aqueous Electrolyte Thermodynamics, Wiley-AIChE, Hoboken, NJ (1986).
  17. HSC Chemistry Software, www.outotec.com.