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Quantitative Determination of Aluminum-Substituted Goethite-Hematite Mixtures by Mossbauer Spectroscopy
Aluminum Goethite Hematite Mossbauer spectroscopy Quantitative mineralogy
2012/1/12
Mixtures of synthetic Al-substituted goethite (α-Fe0.814Al0.186OOH) and hematite (α-Fe1.658Al0.342O3) (75, 50, 25, 3% hematite by weight) were studied by Mössbauer spectroscopy to evaluate the us...
Effect of Solution Conditions on the Proportion and Morphology of Goethite Formed from Ferrihydrite
Ferrihydrite Goethite Hydroxyl Iron Morphology Transmission electron microscopy
2012/2/2
In alkaline media and at 70°C dilute suspensions of ferrihydrite transformed to goethite between pH 11.2 and 14 and to a mixture of goethite and hematite above and below this pH range. Increasing the ...
Effect of pH on the Formation of Goethite and Hematite from Ferrihydrite
Ferrihydrite Goethite Hematite Mossbauer spectroscopy pH X-ray powder diffraction
2012/2/7
Storage of ferrihydrite in aqueous suspensions at 24°C and pHs between 2.5 and 12 for as long as three years resulted in the formation of goethite and hematite. The proportions and crystallinity of th...
Transformation of Iron-Bearing Kaolinite to Iron-Free Kaolinite, Goethite, and Hematite
Goethite Hematite Iron Kaolinite Mossbauer spectroscopy Oxidation Pseudomorphism
2012/2/7
Ferruginous clay partings in limestones of the marine, largely evaporitic, Upper Triassic Mohila Formation (Makhtesh Ramon, Israel) contain hexagonal plates and cube-like bodies up to one millimeter a...
Aluminum-Bearing Goethite in Venezuelan Laterites
Al-goethite Dithionite dissolution Goethite Laterite Venezuela
2012/2/10
The presence of Al-bearing goethites has been unequivocally established in Venezuelan laterite sediments by means of infrared spectroscopy (IR), chemical dissolution, and X-ray powder diffraction (XRD...
The System SiO2-AlOOH-Fe2O3-H2O and the Kaolinitic Stage of the Goethite Facies
SiO2-AlOOH-Fe2O3-H2O Kaolinitic Stage Goethite Facies
2012/2/15
A 25°C, 1 atm total pressure phase diagram for the system SiO2-AlOOH-Fe2O3-H2O, is determined using the Phase Rule and Shreinemaker's technique as in Chesworth (1974). The water-present assemblages so...
The Crystallinity of Minerals—A New Variable in Pedogenetic Processes: A Study of Goethite and Associated Silicates in Laterites
Crystallinity Minerals Pedogenetic Processes Goethite Associated Silicates
2012/2/15
The crystallinity of minerals in terms of crystallite size distribution and lattice perfection is quantified by means of statistical measures derived from X-ray line profiles (2 σ values). A low degre...
The Interaction of Water with Goethite (α-FeOOH) and Amorphous Hydrated Ferric Oxide Surfaces
Goethite (α-FeOOH) Amorphous Hydrated Ferric Oxide Surfaces
2011/11/18
Abstract: The interaction of water with synthetically prepared goethite (α-FeOOH) and amorphous hydrated ferric oxide surfaces was studied using i.r. absorption and water vapor adsorption measurements...
The Influence of Silicate on the Transformation of Lepidocrocite to Goethite
Silicate Transformation Lepidocrocite Goethite
2012/2/17
The mechanism of the transformation of lepidocrocite (γFeOOH) to goethite (αFeOOH) has previously been established and the effect of silicate on the transformation was investigated. Rather than comple...
The conversion of lepidocrocite (γFeOOH) to its more stable polymorph, goethite (αFeOOH) was followed by observing changes in crystal morphology, oxalate solubility, surface area and X-ray diffraction...