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Degradation of Hectorite by Hydrogen Ion

Published online by Cambridge University Press:  01 January 2024

G. T. Kerr ,
R. H. Zimmerman ,
H. A. Fox Jr.  and
F. H. Wells
G. T. Kerr
Affiliation:
Aircraft-Marine Products, Inc., Harrisburg, Pennsylvania, USA
R. H. Zimmerman
Affiliation:
Aircraft-Marine Products, Inc., Harrisburg, Pennsylvania, USA
H. A. Fox Jr.
Affiliation:
Aircraft-Marine Products, Inc., Harrisburg, Pennsylvania, USA
F. H. Wells
Affiliation:
Aircraft-Marine Products, Inc., Harrisburg, Pennsylvania, USA
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Abstract

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Hydrogen hectorite-water sol was prepared using mixed-bed ion-exchange resins. At 25° C., the rate of change of concentration with respect to time was determined for (a) strong-and weak-acid hydrogen ions; (b) low molecular weight, unassociated silicates; and (c) soluble, unassociated magnesium ion.

The experimental data indicate that two consecutive first-order reactions are occurring: (1) strong acid is undergoing a rapid, spontaneous reaction to yield weak acid, and (2) the resulting weak acid is undergoing a slow, spontaneous reaction to yield a neutral clay. The equivalent weight of the strong acid is apparently one-half that of the weak acid. For each milliequivalent of strong-acid hydrogen ion undergoing reaction, one milliequivalent of magnesium ion is released from the crystal lattice. Thus, the acid clay is eventually converted to magnesium clay. In addition, for each milliequivalent of weak-acid hydrogen ion undergoing reaction, one millimole of silica is released from the lattice. Since the release of magnesium ion precedes the release of silica, proton attack is probably occurring at the edges of the crystals. The exact nature of the weak acid is unknown and detailed study would probably be difficult in view of its transitory existence.

Freshly prepared acid hectorite contains approximately 40 meq of hydrogen ion per 100 g clay. Therefore, only 3 percent of the total magnesium is released from the lattice. The lattice structure of the resulting magnesium clay is identical with that of natural hectorite as shown by x-ray diffraction.

Type
Article
Information
Clays and Clay Minerals (National Conference on Clays and Clay Minerals) , Volume 4 , February 1955 , pp. 322 - 329
Copyright
Copyright © The Clay Minerals Society 1955

References

Alexander, G. B., 1953, The reaction of low molecular weight silicic acids with molybdic acid: J. Amer. Chem. Soc., v. 75, p. 5655–5657.CrossRefGoogle Scholar
Brindley, G. W., and Youell, R. F., 1951, A chemical determination of the tetrahedral and octahedral aluminum ions in a silicate: Acta Cryst., v. 4, p. 495–497.CrossRefGoogle Scholar
Chatterjee, B., and Paul, M., 1942, Interaction between hydrogen clays and neutral salts: Indian J. Agr. Sci., v. 12, p. 113–120.Google Scholar
Cheng, K. L., Kurtz, T., and Bray, R. H., 1952, Determination of calcium, magnesium, and iron in limestone: Anal. Chem., v. 24, p. 1640–1641.CrossRefGoogle Scholar
Coleman, N. T., and Harward, M. E., 1953, The heats of neutralization of acid clays and cation exchange resins: J. Amer. Chem. Soc., v. 75, p. 6045–6046.CrossRefGoogle Scholar
Low, P. F., 1955, The role of aluminum in the titration of bentonite: Soil Sci. Soc. Amer. Proc., v. 19, p. 135–139.CrossRefGoogle Scholar
Mukherjee, J. N., Chatterjee, B., and Gaswanni, P. C., 1942, Limiting exchange of aluminum ions from hydrogen clays on the addition of neutral salts: J. Ind. Chem. Soc., v. 19, p. 40–407.Google Scholar
Osthaus, B. B., 1954, Chemical determination of tetrahedral ions in nontronite and montmorillonite: in Clays and clay minerals, Natl. Acad. Sci.—Natl. Res. Council Pub. 327, p. 404–417.Google Scholar
Paver, H., and Marshall, C. E., 1934, The role of aluminum in the reaction of the clays: J. Soc. Chem. Ind. (London), v. 53, p. 750–760.Google Scholar
Ross, C. S., and Hendricks, S. B., 1945, Minerals of the montmorillonite group, their origin and relation to soils and clays: U. S. Geol. Survey Prof. Paper 205-B, p. 23–79.Google Scholar
Slabaugh, W. H., 1952, The heat of neutralization of hydrogen-bentonite: J. Amer. Chem. Soc., v. 74, p. 4462–4464.CrossRefGoogle Scholar