Topic
Gibbsite
About: Gibbsite is a research topic. Over the lifetime, 1995 publications have been published within this topic receiving 48355 citations. The topic is also known as: hydrargillite & zirlite.
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TL;DR: In this article, the first unified equilibrium experimental model of Al ion speciation in waters from pH 4 to 9 was presented, based on the standard Gibbs free energies of formation (ΔG°f).
326 citations
TL;DR: In this paper, the dissolution of kaolinite is interpreted in terms of the surface complexation model, and the dissolution reaction can be interpreted as a coupled release of Al and Si with the detachment of the Al center from the surface lattice structure as the rate-limiting step.
319 citations
TL;DR: The most favorable soil conditions for interlayer formation appear to be: moderate pH (4·6-5·8), frequent wetting and drying cycles, and low organic matter content as mentioned in this paper.
Abstract: Vermiculites and smectites in soils and sediments are frequently partially interlayered or “chloritized”. Dioctahedral expansible layer silicates are those most frequently interlayered, and hydroxy-Al appears to be the principal component of the non-exchangeable interlayer material. The most favorable soil conditions for interlayer formation appear to be: moderate pH (4·6–5·8), frequent wetting and drying cycles, and low organic matter content. In marine sediments, hydroxy-Mg interlayering may be significant. Soil-derived clays containing partially filled hydroxy-Al “brucite” sheets may be filled out with hydroxy-Mg. Under reducing conditions, hydroxy-Fe interlayers may be important. Depending on the OH/Al ratio and Al content of hydroxy-Al interlayers, expansible layer silicate may either promote or retard the formation of gibbsite. Interlayered expansible layer silicates also may be precursors to kaolinite.
317 citations
TL;DR: Adsorption isotherms for fulvic and humic acids on synthetic gibbsite and goethite and on a natural imogolite were obtained with the help of spectra of the adsorption complexes, and measurements of hydroxyl displaced as discussed by the authors.
Abstract: Adsorption isotherms were obtained for fulvic and humic acids on synthetic gibbsite and goethite and on a natural imogolite. The results were interpreted with the help of spectra of the adsorption complexes, and measurements of hydroxyl displaced. The mechanism of adsorption involved ligand exchange with the surface hydroxyl groups and hydrogen bonding. The hydroxyl groups displaced included singly coordinated species on the (100) face of goethite and on the edge faces of gibbsite. The doubly coordinated hydroxyl groups on the (001) face of gibbsite were not replaced, and this face adsorbed only un-ionized fulvic acid probably by a hydrogen bonding mechanism. Imogolite adsorbed most fulvic acid because of its high porosity. Only isolated places on its surface reacted with fulvic acid to form carboxylate groups.
302 citations
TL;DR: In this article, the structure determination by MEGAW (1934) was confirmed and the revised interatomic distances as well as the hydrogen positions were reported, based on diffraotometer data the struoture of gibbsite has been refined by least squares oalculations.
Abstract: On tho basis of now diffraotometer data the struoture of gibbsite has been refined by least-squares oalculations. The structure determination by MEGAW (1934) was confirmed. The revised interatomic distances as well as the hydrogen positions are reported.
290 citations