Advertisement

Clays and Clay Minerals

, Volume 3, Issue 1, pp 117–145 | Cite as

Reference Chlorite Characterization for Chlorite Identification in Soil Clays

  • R. Torrence Martin
Article

Abstract

Literature pertaining to differential thermal and X-ray diffraction of chlorite minerals is reviewed. Optical, DTA, and X-ray data for eleven chlorite samples of clinochlore, prochlorite, thuringite, corundophilite, and leuchtenbergite are given. The effect of particle size (105 to −1 μ) on DTA, X-ray diffraction, glycol retention, and cation exchange capacity are given for two thuringites, one clinochlore, and one prochlorite.

Identification of chlorite by DTA in a soil clay containing a mixture of minerals is improbable at the present time except under very favorable circumstances. However, for relatively pure chlorite samples, variations in chemical composition are reflected in the differential thermal curves. The largest change in the thermogram is produced by ferric iron which lowers the peak temperature from 720° C to 610° C. Differences in thermal behavior between low and high ferric iron chlorite species are maintained for any given particle size. Chlorite thermograms obtained by different investigators show much greater variation than the differences in thermograms for other clay minerals determined on different equipment.

X-ray diffraction can be used to positively identify chlorite in a soil clay, (a) by careful analysis of reflections at least as great as 14 Å, and (b) by the influence heat treatment (550° C for 30 minutes) has on the X-ray pattern. Heat treatment produces marked changes in the X-ray pattern of the finer particle size samples and the magnitude of the change effected is greater for high iron chlorites (thuringite) than for low iron chlorites (clinochlore and prochlorite). Olivine is not the recrystallization product for thuringite. The smallest size fractions show no tendency toward vermiculite or montmorillonoid.

Cation exchange capacity for silt size chlorites varies from 4 to 32 m.e./100gm., and for −2 μ chlorite particles from 30 to 47 m.e./100gm. Cation exchange capacities for −2 μ and −1 μ chlorites are essentially the same.

Ethylene glycol retention increases with decreasing particle size. Glycol retention for −2 μ chlorite samples varies from 25 to 40 mg, glycol/gm, clay. For −1 μ chlorite material, glycol retention is 2 to 4 times greater than for −2 μ material.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Arens, P. L. (1951) A study of differential thermal analysis of clays and clay minerals: Doctorate dissertation, Wageningen, Netherlands, 131 pp.CrossRefGoogle Scholar
  2. Barshad, I. (1948) Vermiculite and its relation to biotite as revealed by base exchange reactions, X-ray analyses, differential thermal curves, and water content: Am. Mineral., vol. 33, pp. 655–678.Google Scholar
  3. Brindley, G. W. (1951) X-ray identification and crystal structures of clay minerals: London, The Mineralogical Society, 345 pp.Google Scholar
  4. Brindley, G. W., and Ali, S. Z. (1950) X-ray study of thermal transformations in some magnesian chlorite minerals: Acta Cryst., vol. 3, pp. 25–30.CrossRefGoogle Scholar
  5. Cailère, S., and Hénin, S. (1949a) Transformation of minerals of montmorillorite family into 10 A micas: Min. Mag., vol. 28, pp. 606–611.Google Scholar
  6. Cailère S., and Hénin, S. (1949b) Experimental formation of chlorite from montmorillonite: Min. Mag., vol. 28, pp. 612–620.Google Scholar
  7. Earley, J. W., et al. (1953) Thermal dehydration, and X-ray studies on montmorillonite: Am. Mineral., vol. 38, pp. 770–783.Google Scholar
  8. Grim, R. E. (1953) Clay mineralogy: New York, McGraw-Hill, 384 pp.CrossRefGoogle Scholar
  9. Hey, M. H. (1954) A new revieiv of chlorites: Min. Mag., vol. 30, pp. 277–292.Google Scholar
  10. Jeffries, C. D., et al. (1953) Mica weathering sequence in the Highfield and Chester soil profiles: Soil Sci. Soc. Am. Proc, vol. 17, pp. 337–339.CrossRefGoogle Scholar
  11. Lambe, T. W. (1952) Differential thermal analysis: High, Res. Board Proc., vol. 31, pp. 621–642.Google Scholar
  12. Kerr, P. F., et al. (1949) Differential thermal analysis of reference clay mineral specimens: New York, Columbia University, 48 pp.Google Scholar
  13. Mackenzie, R. C., and Farquharson, K. R. (1952) Standardisation of differential thermal analysis technique, Comité International pour L’Étude des Argiles.Google Scholar
  14. Martin, R. T. (1954) Clay minerals of five New York Soil profiles: Soil Sci., vol. 77, pp. 389–399.CrossRefGoogle Scholar
  15. Martin, R. T. (In press, 1954) Ethylene glycol retention by clays: Soil Sci. Soc. Am. Proc.Google Scholar
  16. Mitchell, W. A. (1953) Oriented — aggregate specimens of clay for X-ray analysis made by pressure: Clay Minerals Bull. vol. 2, pp. 76–78.CrossRefGoogle Scholar
  17. Orcel, J. (1927) Recherches sur la composition chimique des chlorites; Chapter IV, L’eau de chlorites: Soc. Fran. Min. Bull., vol. 50, pp. 273–322.Google Scholar
  18. Orcel, J. (1929) Complément a l’analyse thermique des chlorites: Soc. Fran. Min. Bull., vol. 52, pp. 194–197.Google Scholar
  19. Orcel, J., and Cailère, S. (1938) Nouvelles observations sur les transformations des prochlorites magnesiennes sous l’action de la chaleur: Compt. Rend., vol. 207, pp. 788–790.Google Scholar
  20. Orcel, J., and Renaud, P. (1941) Étude du dégagement d’hydrogène associé au depart de Veau de constitution des chlorites ferromognésiennes: Compt. Rend., vol. 212, pp. 918–921.Google Scholar
  21. Peech, M. (1947) Methods of soil analysis for soil-fertility investigations: U.S.D.A., Circular No. 757, pp. 9–11.Google Scholar
  22. Sabatier, G. (1950) Sur l’ influence de la dimension des cristaux de chlorites sur leurs courbes d’analyse thermique différentielle: Soc. Fran. Min. Bull., vol. 73, pp. 43–48.Google Scholar
  23. Speil, S., et al. (1945) Differential thermal analysis: U.S. Bur. Mines Tech. Paper 664, 81 pp.Google Scholar
  24. Winchell, A. N. (1951) Elements of optical mineralogy. Part 11: Descriptions of minerals: New York, John Wiley & Sons, 551 pp.Google Scholar

Copyright information

© The Clay Minerals Society 1954

Authors and Affiliations

  • R. Torrence Martin
    • 1
  1. 1.Massachusetts Institute of TechnologyUSA

Personalised recommendations