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Mechanisms of Gibbsite Crystallization from Partially Neutralized Aluminum Chloride Solutions

Published online by Cambridge University Press:  02 April 2024

Pa Ho Hsu*
Affiliation:
Department of Soils and Crops, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08903

Abstract

To interpret the erratic conditions, rates, and extent of gibbsite crystallization from partially neutralized A1C13 solution, the following hypothesis is proposed: The initial OH-A1 polymers in the freshly prepared solutions were probably unstable and transformed into either gibbsite or stable OH-A1 polymers via two different reaction paths. In the presence of nuclei, the OH-A1 polymers dissociated into monomeric ions, which then deposited onto nuclei to form gibbsite. In the absence of nuclei, the unstable polymers slowly converted to stable polymers. The erratic stability of OH-Al solutions and gibbsite crystallization are therefore attributed to the relative magnitudes of these two reaction paths which, in turn, are attributed to two key factors: (1) the distribution of unstable vs. stable OH-Al polymers; and (2) the presence or absence of nuclei. The duration of aging of the parent solution governed the distribution of unstable vs. stable polymers. The rate of neutralization resulted in varying localized high alkalinity in OH-Al solution preparation and thus varying development of nuclei.

Type
Research Article
Copyright
Copyright © 1988, The Clay Minerals Society

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Footnotes

1

New Jersey Agricultural Experiment Station Publication No. D-15420-1-86.

References

Akitt, J. W. and Farthing, A., 1978 New 27Al NMR studies of the hydrolysis of the aluminum(III) ions J. Magn. Reson. 32 345352.Google Scholar
Akitt, J. W. and Farthing, A., 1981 Aluminum-27 nuclear magnetic resonance studies of the hydrolysis of alumi-num(III). Part 2. Gel-permeation chromatography J. Chem. Soc. Dalton Trans. 1981 16061608.CrossRefGoogle Scholar
Akitt, J. W., Greenwood, N. N., Khandelwal, B. and Lester, G., 1972 27Al nuclear magnetic resonance studies of the hydrolysis and polymerization of the hexa-aquo-alumi-num(III) cation J. Chem. Soc. Dalton Trans. 1972 604610.CrossRefGoogle Scholar
Bertsch, P. M., 1987 Conditions for Al13 polymerformation in partially neutralized Al solutions Soil Sci. Soc. Amer. J. 51 825828.CrossRefGoogle Scholar
Bertsch, P. M., Layton, W. J. and Barnhisel, R. I., 1986 Speciation of hydroxy-Al solutions by wet chemical and 27Al NMR methods Soil Sci. Soc. Amer. J. 50 14491454.CrossRefGoogle Scholar
Bertsch, P. M., Thomas, G. W. and Barnhisel, R. I., 1986 Characterization of hydroxy-aluminum solutions by aluminum-27 nuclear magnetic resonance spectroscopy Soil Sci. Soc. Amer. J. 50 825830.CrossRefGoogle Scholar
Denney, D. Z. and Hsu, P. H., 1986 27Al nuclear magnetic resonance and ferron kinetic studies of partially neutralized AlCl3 solutions Clays & Clay Minerals 34 604607.CrossRefGoogle Scholar
Frink, C. R. and Peech, M., 1963 Hydrolysis of the aluminum ion in dilute aqueous solutions Inorg. Chem. 3 473478.CrossRefGoogle Scholar
Hsu, P. H., 1963 Effect of initial pH, phosphate and silicate on the determination of aluminum with Aluminon Soil Sci. 96 230238.CrossRefGoogle Scholar
Hsu, P. H., 1966 Formation of gibbsite from aging hydroxy-aluminum solutions Soil Sci. Soc. Amer. Proc. 30 173176.CrossRefGoogle Scholar
Hsu, P. H., Dixon, J. B. and Weed, S. B., 1977 Aluminum hydroxides and oxyhydrox-ides Minerals in Soil Environments Madison, Wisconsin Soil Sci. Soc. America 99143.Google Scholar
Hsu, P. H. and Bates, T. F., 1964 Formation of X-ray amorphous and crystalline aluminum hydroxides Mineral Mag. 33 749768.Google Scholar
Hsu, P. H. and Rich, C. I., 1960 Aluminum fixation in a synthetic cation exchanger Soil Sci. Soc. Amer. Proc. 24 2125.CrossRefGoogle Scholar
Johansson, G., 1960 On the crystal structure of some basic aluminum salts Acta Chem. Scand. 14 771773.CrossRefGoogle Scholar
Johansson, G., 1963 On the crystal structure of basic aluminum sulfate. 13Al2O36SO3H2O Ark. Kemi. 20 321342.Google Scholar
Kittrick, J., 1966 The free energy of formation of gibbsite and Al(OH)4- from solution measurements Soil Sci. Soc. Amer. Proc. 30 595598.CrossRefGoogle Scholar
Schoen, R. and Roberson, E. C., 1970 Structures of aluminum hydroxides and geochemical implications Amer. Mineral. 55 4377.Google Scholar
Singh, S.S., 1974 The solubility product of gibbsite at 15°, 25° and 35°C Soil Sci. Soc. Amer. Proc. 38 415417.CrossRefGoogle Scholar
Smith, R. W., 1971 Relations among equilibrium and non-equilibrium aqueous species of aluminum hydroxy complexes Adv. Chem. Ser. 106 250279.CrossRefGoogle Scholar
Smith, R. W. and Hem, J. D., 1972 Effect of aging on aluminum hydroxy complexes in dilute aqueous solutions U.S. Geol. Surv. Water Supply Pap. 1827-D .Google Scholar
Teagarden, D. L., Koslowski, J. F., White, J. L. and Hem, S. L., 1981 Aluminum chlorohydrate. I: Structural studies J. Pharm. Sci. 70 758761.CrossRefGoogle Scholar
Tsai, P. P. and Hsu, P. H., 1984 Studies of aged OH-Al solutions using kinetics of Al-Ferron reactions and sulfate precipitation Soil Sci. Soc. Amer. J. 48 5965.CrossRefGoogle Scholar
Tsai, P. P. and Hsu, P. H., 1985 Aging of partially neutralized aluminum solutions of NaOH/Al molar ratio = 2.2 Soil Sci. Soc. Amer. J. 49 10601065.CrossRefGoogle Scholar
Turner, R. C., 1976 Effect of aging on properties of poly-nuclear hydroxaluminum cations Can. J. Chem. 54 15281534.CrossRefGoogle Scholar
Turner, R. C., 1976 A second species of polynuclear hy-droxyaluminum cation, its formation and some of its properties Can. J. Chem. 54 19101915.CrossRefGoogle Scholar
Turner, R. C. and Ross, C. G., 1970 Conditions in solution during the formation of gibbsite in dilute Al salts solutions. 4. Effect of Cl concentration and temperature and a proposed mechanism for gibbsite formation Can. J. Chem. 48 723729.CrossRefGoogle Scholar