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Reaction mechanism for the ferric chloride leaching of sphalerite

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Abstract

Reaction mechanisms for the ferric chloride leaching of sphalerite are proposed based on data obtained in leaching and dual cell experiments presented in this work and in a previous study. The results from the leaching experiments show that at low concentrations the rate is proportional to [Fe3+]T 0.5 and [Cl-]T 0.43 but at higher concentrations the reaction order with respect to both [Fe3+]T and [Cl-]T decreases. Using dual cell experiments which allow the half cell reactions to be separated, increased rates are observed when NaCl is added to the anolyte and to the catholyte. The increase in rate is attributed to a direct, anodic electrochemical reaction of Cl- with the mineral. When NaCl is added only to the catholyte, a decrease in the rate is observed due to a decrease in theE 0 of the cathode which is attributed to the formation of ferric-chloro complexes. Several possible electrochemical mechanisms and mathematical models based on the Butler-Volmer relation are delineated, and of these, one model is selected which accounts for the experimentally observed changes in reaction order for both Fe3+ and Cl-. This analysis incorporates a charge transfer process for each ion and an adsorption step for ferric and chloride ions. The inhibiting effect of Fe2+ noted by previous investigators is also accounted for through a similar model which includes back reaction kinetics for Fe2+. The proposed models successfully provide a theoretical basis for describing the role of Cl-, Fe3+, and Fe2+ as well as their interrelationship in zinc sulfide leaching reactions. Possible applications of these results to chloride leaching systems involving other sulfides or complex sulfides are considered.

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Abbreviations

A :

Reaction area

R:

Universal gas constant

T :

Temperature

F:

Faraday's constant

K :

Equilibrium constant

E m :

Mixed potential

[Fe3+]T :

Total ferric ion concentration

[Cl-]T :

Total chloride ion concentration

ks :

Apparent reaction rate constant for surface reaction for an isometric particle

r 0 :

Initial particle radius

dr/dt :

Linear reaction velocity constant

t :

Elapsed time

n ZnS :

Number of moles of ZnS remaining at time t

k aj,k′aj :

Rate constants for the forward and reverse directions, respectively, of the anodic process given by reaction (j)

k cj, k′cj :

Rate constants for the forward and reverse directions, respectively, of the cathodic process given by reaction (j)

n aj, ncj :

Number of electrons transferred in the anodic or cathodic charge transfer process, respectively, given by reaction (j)

z aj, zcj :

Total number of electrons transferred in the anodic and cathodic half cell reactions, respectively, given by reaction (j)

α :

Fraction of ZnS reacted

β aj,βcj :

Charge transfer coefficients for the anodic and cathodic process, respectively, described by reaction (j)

θ A,θC :

Fraction of total available surface sites occupied by adsorbed Cl− and Fe3+, respectively

ϕ :

Fraction of total available surface sites not occupied by adsorbed species

References

  1. Z-M. Jin, G.W. Warren, and H. Henein:Metall. Trans. B, 1984, vol. 15B, pp. 5–12.

    Article  CAS  Google Scholar 

  2. G.W. Warren:J. Metals, 1983, vol. 35(4), pp. 42–7.

    CAS  Google Scholar 

  3. G.W. Warren:J. Metals, 1982, vol. 34)4), pp. 51–5.

    CAS  Google Scholar 

  4. J. P. Wilson and W. W. Fisher:J. Metals, 1981, vol. 33(2), pp. 52–7.

    CAS  Google Scholar 

  5. H. Majima, Y. Awakura, and N. Misaki:Metall. Trans. B, 1981, vol. 12B, pp. 645–49.

    Article  CAS  Google Scholar 

  6. J.E. Dutrizac and R.J.C. MacDonald:Metall. Trans. B, 1978, vol. 9B, pp. 543–51.

    CAS  Google Scholar 

  7. B. R. Palmer, C. O. Nebo, M. F. Rau, and M. C. Furstenau:Metall. Trans. B, 1981, vol. 12B, pp. 595–601.

    Article  CAS  Google Scholar 

  8. M. E. Wadsworth and T-K. Zhong: Proceedings NATO Advanced Research Inst. on Hydromet. Process Fundamentals, Cambridge, U.K., July 1982, NATO Scientific Affairs Div., Brussels, Belgium.

  9. G. P. Demopoulos: M.S.Thesis, McGill University, Montreal, Canada, 1977.

    Google Scholar 

  10. R.J. Jan, M. T. Hepworth, and V. G. Fox:Metall. Trans. B, 1976, vol. 7B, pp. 353–61.

    Article  CAS  Google Scholar 

  11. H. Su: Ph.D. Dissertation, University of Idaho. Moscow,ID, 1976.

    Google Scholar 

  12. P. C. Rath, R. K. Paramguru, and P. K. Jena:Hydrometallurgy, 1981, vol. 6, pp. 219–25.

    Article  CAS  Google Scholar 

  13. R.Y. Wan, J. D. Miller, J. Foley, and S. Pons:Electrochemistry in Mineral and Metal Processing, Electrochemical Society, 1984, pp. 391-416.

  14. J. N. Butler:Ionic Equilibrium, Addison-Wesley Co., Inc., Reading, lMA, 1964, p. 264.

    Google Scholar 

  15. A.R. Despic and J.O'M. Bockris:J. Chem. Phys., I960, vol. 32, p. 389.

    Article  Google Scholar 

  16. K. J. Vetter:Electrochemical Kinetics, Academic Press, New York,NY, 1967.

    Google Scholar 

  17. J. B. Hiskey and M. E. Wadsworth:Metall. Trans. B, 1975, vol. 6B, pp. 183–90.

    CAS  Google Scholar 

  18. J.B. Hiskey:Inst. Min. Metall., 1979, vol. 88C, pp. 145–52.

    Google Scholar 

  19. J.O'M. Bockris and G. A. Razumney:Fundamental Aspects of Electrocrystallization, Plenum Press, New York, NY, 1967, p. 36.

    Google Scholar 

  20. R. A. Robinson and R. H. Stokes:Electrolyte Solutions, Academic Press,New York,NY, 1955, pp. 465, 487.

    Google Scholar 

  21. H.S. Harned and B.B. Owen:Physical Chemistry of Electrolytic Solutions, 3rd ed., Reinhold Pub. Corp., New York,NY, 1958, pp. 726–51.

    Google Scholar 

  22. D. Dobos:Electrochemical Data, Elsevier Scientific Pub. Co., Amsterdam, 1975.

    Google Scholar 

  23. H. Majima and Y. Awakura:Metall. Trans. B, 1981, vol. 12B, pp. 141–47.

    Article  CAS  Google Scholar 

  24. J.D. Miller: inMetallurgical Treatises, J.K. Tien and J.F. Elliott, eds., AIME, Warrendale, PA, 1981, pp. 95–117.

    Google Scholar 

  25. L.W. Beckstead and J.D. Miller:Metall. Trans. B, 1977, vol. 8B, pp. 19–29.

    Article  CAS  Google Scholar 

  26. I.H. Warren and E. Devuyst:International Symposium on Hydrometallurgy, 1972, AIME,New York,NY, pp. 229–64.

    Google Scholar 

  27. W. K. Tolley, H. H. Huang, and J. D. Miller: Proceedings of the International Symposium on Chloride Hydrometallurgy Brussels, Benelux,Metallurgie, 1977, pp. 96-133.

  28. Y. Awakura, S. Kamei, and H. Majima:Metall. Trans. B, 1980, vol. 11B, pp. 377–81.

    Article  CAS  Google Scholar 

  29. M.E. Wadsworth and D.R. Wadia:Trans. AIME, 1955. vol. 203, pp. 755–59.

    Google Scholar 

  30. H. Majima, Y. Awakura, and T. Mishima:Metall. Trans. B, 1984, vol. 16B, pp. 23–30.

    Google Scholar 

  31. S-H. Kim, H. Henein, and G. W. Warren:Metall. Trans. B, in press.

  32. B. Pesic and F. A. Olson:Metall. Trans. B, 1983, vol. 14B, pp. 577–88.

    Article  CAS  Google Scholar 

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Authors and Affiliations

  1. Department of Metallurgical Engineering and Materials Science, Carnegie-Mellon University, 15213, Pittsburgh, PA

    G. W. Warren (Associate Professor) & H. Henein (Assistant Professor)

  2. Chengdu University of Science and Technology, The People's Republic of China

    Zuo-Mei Jin (Associate Professor)

Authors
  1. G. W. Warren
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  2. H. Henein
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  3. Zuo-Mei Jin
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Warren, G.W., Henein, H. & Jin, ZM. Reaction mechanism for the ferric chloride leaching of sphalerite. Metall Trans B 16, 715–724 (1985). https://doi.org/10.1007/BF02667508

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