Catalysis Letters

, Volume 10, Issue 1–2, pp 63–69 | Cite as

Charge reduction and regeneration in K+, Na+, Mg2+, Ni2+ and Co2+-exchanged Wyoming Bentonite

  • J. H. Purnell
  • J. Williams
  • Lu Yun


Controlled calcination of ion-exchanged Wyoming Bentonite in the presence and absence of ammonia leads to layer charge reductions. Detailed chemical analyses of both unexchangeable and exchangeable species lead to the conclusion that in no case is there migration of the original interlamellar cations into the octahedral region of the layers although, in terms of ionic radius alone, Mg2+, Ni2+ and, possibly Co2+, might be expected to do so. The production of unexchangeable Mg, Ni or Co, is identified as resulting from high temperature hydrolysis leading to hydroxide or oxide formation.


Montmorillonite Bentonite, clay charge reduction/regeneration cation migration 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [1]
    R.L. Cook, J. Amer. Soc. Agron. 27 (1935) 297.Google Scholar
  2. [2]
    R. Chaminade, C.R. Acad. Sci. Paris 254 (1962) 902.Google Scholar
  3. [3]
    R. Greene-Kelly, Clay Min. Bull. 2 (1953) 52.Google Scholar
  4. [4]
    J.D. Russell and V.C. Farmer, Clay Min. Bull. 5 (1964) 443.Google Scholar
  5. [5]
    J. Williams, J.H. Purnell and J.A. Ballantine, Catal. Lett. 9 (1991) 115.Google Scholar
  6. [6]
    J.H. Purnell, J.M. Thomas, P. Diddams, J.A. Ballantine and W. Jones, Catal. Lett. 2 (1989) 125.Google Scholar
  7. [7]
    O. Stern, Electrochem. 30 (1924) 508.Google Scholar
  8. [8]
    B.L. Sawhney, Clays and Clay Miner. 20 (1972) 93.Google Scholar
  9. [9]
    Lu Yun, Ph.D. Thesis, University of Wales, 1990.Google Scholar
  10. [10]
    G. Ertem, Clays and Clay Miner. 20 (1972) 199.Google Scholar
  11. [11]
    R. Okazaki, H.W. Smither and C.D. Moodie, Soil Science 93 (1962) 343; 97 (1964) 202.Google Scholar
  12. [12]
    G.K. Sansom, R.G. Smith and D. White, Trans. Brit. Cer. Soc. 67 (1968) 93.Google Scholar

Copyright information

© J.C. Baltzer A.G. Scientific Publishing Company 1991

Authors and Affiliations

  • J. H. Purnell
    • 1
  • J. Williams
    • 1
  • Lu Yun
    • 1
  1. 1.Department of ChemistryUniversity College of SwanseaSingleton ParkUK

Personalised recommendations