Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-28T13:42:45.328Z Has data issue: false hasContentIssue false

Hydrothermal and dry-heat fixation of K by soil clays and the effects on C.E.C., surface area and mineralogy

Published online by Cambridge University Press:  09 July 2018

C. E. Davis
Affiliation:
Dept. of Mines, Hope, Kingston 6, Jamaica
N. Ahmad
Affiliation:
University of the West Indies, St. Augustine, Trinidad
R. L. Jones
Affiliation:
Dept. of Agronomy, University of Illinois, Urbana, Illinois, U.S.A.

Abstract

Fixation of K by soil clays and selected reference clay minerals was induced by dry heat and hydrothermal procedures, at 100°C, 200°C and 380°C. Appreciable amounts were fixed at all temperatures. In the cases of the samples treated hydrothermally the amounts fixed increased with pressure.

Fixation by dry heating at 380°C was significantly greater than at 100°C and 200°C respectively. Fixation under hydrothermal conditions increased in order 380°C > 200°C > 100°C.

Reductions in cation exchange capacities (and surface areas) were associated with fixation, indicating that some fixation was due to ion exchange. Changes in mineralogy in some of the samples also support the conclusion that ion exchange was partly responsible for fixation. Some of the fixation under hydrothermal conditions was due to the formation of insoluble K-compounds - as for example the synthesis of a new mineral when one sample was treated.

The lattice-iron content of the clays may have influenced their hydrothermal behaviour. Thus the Princes Town Clay ( > 7-5 % lattice-iron) and three nontronites (≫ 7-5 % lattice-iron) showed appreciable lattice collapse after hydrothermal treatment, while Wyoming bentonite and hectorite (<3-5%) lattice-iron) showed no collapse at all.

The degree of crystallinity of the mineral may also have influenced its hydrothermal reaction. For example, the highly disordered soil kaolinite (St John's) was much more reactive than the more ordered Georgia kaolinite. Also, the more-ordered reference clays fixed relatively less K at 380°C than the less-ordered soil clays.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1971

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Barshad, I. (1954) Soil Sci. 78, 57.Google Scholar
Barshad, I. & Kishk, F. (1969) Clays Clay Miner. 18, 127.CrossRefGoogle Scholar
Carter, D.L., Heilman, M.D. & Gonzalez, C.L. (1965) Soil Sci. 100, 356.Google Scholar
Chenery, R.M. (1952) Soils of Central Trinidad. Govt. Printer, Trinidad.Google Scholar
Ewell, R.H. & Insley, H. (1935) Jour. Res. Nat. Bur. Standard 15, 173.Google Scholar
Grim, R.E. (1953) Clay Mineralogy. McGraw-Hill Book Co. Inc., New York.Google Scholar
Gruner, J.W. (1939) Am. Miner. 24, 624.Google Scholar
Malquori, A. & Wiklander, L. (1952) Trans. Int. Cong. Soil Sci. No. 1, 1.Google Scholar
Nollw. (1936) Naus. Jahrb. Mineral Geol. Beilage Bd. A 70, 65.Google Scholar
Page, A.L., Burge, W.D., Ganje, T.J. & Garber, M.J. (1967) Proc. Soil Sci. Soc. Am. 31, 337.Google Scholar
Page, J.B. & Baver, D.L. (1940) Proc. Soil Sci. Soc. Am. 4, 140.Google Scholar
Rose, J.H., Adler, I. & Flanagan, F. (1963) Appi. Spec. 17, 81.Google Scholar
Schuffelen, A.C. & Marel, Van Der H.W. (1955) Potassium Symposium (1955), 157.Google Scholar
Vernon, K.C. & Carroll, D.M. (1966) Soil and Land Use Surveys No. 18 Barbados. U.W.I., St. Augustine, Trinidad, W.l.Google Scholar
Wear, J.I. & White, J.L. (1951) Soil Sci. 71, 1.CrossRefGoogle Scholar
Weir, A.H. (1965) Clay Miner. 6, 17.CrossRefGoogle Scholar