Distinguishing Kaolinites and Smectite Clays from Central and Eastern Uganda Using Acidity, pH, Colour and Composition

I Z Mukasa-Tebandeke,G W Nyakairu,M Ntale,A Schumann,F Lugolobi,S A Nyanzi,P J M Ssebuwufu

doi:10.4236/ajac.2015.61006

I Z Mukasa-Tebandeke, G W Nyakairu + Show 5 more

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https://doi.org/10.4236/ajac.2015.61006

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Abstract

The Langmuir isotherms of 1-aminobutane in isohexane slurries showed increase in clay acidity with increase in concentration of mineral acid used to leach the clay as well as the temperature at which the clay was thermally activated prior to experimentation involving adsorption of 1-aminobutane. The values of acidity for Central Uganda were low ranging from 0.07 mol/g to 0.32 mol/g yet those for clays from Eastern Uganda were high ranging from 0.1 mol/g to 1.85 mol/g. Based on acidity, pH, elemental and mineral compositions, the clays from Central Uganda were found to be kaolinites or halloysites, yet Eastern Uganda clays were resolved to contain nontronite and kaolinite.

Highlights

Clays are collectively called alumino-silicates as they contain aluminium oxide and silicon dioxide as universal minerals; and are classified into phyllosilicates and layers silicates [1].As early as the 1940s, the active part of a cracking clay catalyst had been described to be the Al (IV) ion andHow to cite this paper: Mukasa-Tebandeke, I.Z., Ssebuwufu, P.J.M., Nyanzi, S.A., Schumann, A., Ntale, M., Nyakairu, G.W. and Lugolobi, F. (2015) Distinguishing Kaolinites and Smectite Clays from Central and Eastern Uganda Using Acidity, pH, Colour and Composition
The fact that acid-leached clays showed increasing surface acidity with increase in concentration of acid used to leach the clay revealed that surface hydrogens and hydroxyl groups on the silica skeleton increased
Increase in surface acidity depicted that the interlayer octahedral ions like Fe3+, Fe2+, Mn2+, Ti4+ etc were progressively replaced by hydrogen ions as the concentration of the acid increased

Summary

Introduction

Clays are collectively called alumino-silicates as they contain aluminium oxide and silicon dioxide as universal minerals; and are classified into phyllosilicates and layers silicates [1].As early as the 1940s, the active part of a cracking clay catalyst had been described to be the Al (IV) ion andHow to cite this paper: Mukasa-Tebandeke, I.Z., Ssebuwufu, P.J.M., Nyanzi, S.A., Schumann, A., Ntale, M., Nyakairu, G.W. and Lugolobi, F. (2015) Distinguishing Kaolinites and Smectite Clays from Central and Eastern Uganda Using Acidity, pH, Colour and Composition. Clays are collectively called alumino-silicates as they contain aluminium oxide and silicon dioxide as universal minerals; and are classified into phyllosilicates and layers silicates [1]. As early as the 1940s, the active part of a cracking clay catalyst had been described to be the Al (IV) ion and. How to cite this paper: Mukasa-Tebandeke, I.Z., Ssebuwufu, P.J.M., Nyanzi, S.A., Schumann, A., Ntale, M., Nyakairu, G.W. and Lugolobi, F. (2015) Distinguishing Kaolinites and Smectite Clays from Central and Eastern Uganda Using Acidity, pH, Colour and Composition. Found to occupy only a small part of the surface. This active part of aluminium in four coordinate forms constitutes acidity [2]. The smectites have high cation exchange capacity (CEC), and kaolinites have negligible CEC [3]

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