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Dehydroxylation of Aluminous Goethite: Unit Cell Dimensions, Crystal Size and Surface Area
Al-substitution Crystal size Dehydroxylation Goethite Hematite Specific surface area Unit cell
2011/12/27
This work investigates unit cell dimensions, crystal size and specific surface area of aluminous goethite that was progressively dehydroxylated to form hematite. Goethite synthesized from the ferrous ...
The Use of Color to Quantify the Effects of pH and Temperature on the Crystallization Kinetics of Goethite Under Highly Alkaline Conditions
Color Colorimetry Crystallization Goethite Hematite Kinetics L*a*b* color space
2011/12/28
The crystallization kinetics of goethite were studied colorimetrically under highly alkaline conditions (pH 10.1–12.2) at temperatures from 40° to 85°C. Color changes during crystallization from fresh...
Fast and Slow Phosphate Sorption by Goethite-Rich Natural Materials
Adsorption Ferrihydrite Goethite Iron oxides Phosphate Porosity Silicate Sorption
2011/11/30
Abstract: Although phosphate sorption by goethite and other less-abundant Fe oxides strongly influences the concentration of this anion in the soil solution and aquatic environments, relatively little...
Color Variations Associated with Rapid Formation of Goethite from Proto-Ferrihydrite at pH 13 and 40°C
Crystallization Colorimetry Goethite Infrared spectroscopy L*a*b* color space UV-VIS-NIR spectroscopy X-ray diffractometry
2011/12/31
Color variations from brown to yellow of synthesized goethite have been studied colorimetrically and spectroscopically. Goethite with various colors was synthesized at pH 13 and 40°C by varying the in...
Dithionite as a Dissolving Reagent for Goethite in the Presence of EDTA and Citrate. Application to Soil Analysis
Dithionite Goethite Iron analysis Iron dissolution
2011/12/31
A synergistic effect of reductant and complexant is observed in the dissolution of goethite by dithionite and citrate or EDTA. The rate data are interpreted using the surface complexation approach to ...
X-ray Powder Diffraction Rietveld Characterization of Synthetic Aluminum-Substituted Goethite
Aluminum Crystallinity Goethite Rietveld refinement X-ray powder diffraction
2011/12/31
Rietveld X-ray powder diffraction (XRD) analysis has been evaluated as a procedure for characterizing Al-substituted goethite according to the Rietveld scale factor, unit-cell parameters, and atom pos...
Transformation of Akaganeite into Goethite and Hematite in the Presence of Mn
Akaganeite Goethite Hematite Manganese Transmission electron microscopy X-ray powder diffraction
2011/12/31
The interaction of Mn and akaganéite in neutral to alkaline media has been investigated using X-ray powder diffraction and transmission electron microscopy. Akaganéite transformed into goethite and/or...
Mn-Substituted Goethite and Fe-Substituted Groutite Synthesized at Acid pH
Goethite Groutite Iron Manganese Solid solution Synthesis Vegard's law X-ray powder diffraction
2012/1/5
Mn-substituted iron oxides were synthesized by coprecipitating Fe(NO3)3 and Mn(SO4) solutions with NH4OH, adjusting the suspensions to pH 4 or 6, and then keeping the suspensions at 55°C for 62 days. ...
Quantitative Determination of Hematite and Goethite in Lateritic Bauxites by Thermodifferential X-ray Powder Diffraction
Bauxite Goethite Hematite Iron Mineral analysis Thermal treatment X-ray powder diffraction
2012/1/9
An X-ray thermodifferential powder diffraction method for the quantitative determination of goethite and hematite in lateritic bauxites has been developed and consists of measuring the integrated inte...
Influence of Silicon and Phosphorus on Structural and Magnetic Properties of Synthetic Goethite and Related Oxides
Electron diffraction Ferrihydrite Goethite Mossbauer spectroscopy Phosphorus Silicon X-ray powder diffraction
2012/1/9
A series of synthetic goethites containing varying amounts of Si and P dopants were characterized by X-ray powder diffraction, electron diffraction, microbeam electron diffraction, and M鰏sbauer spectr...
Effect of Silicate Species on the Transformation of Ferrihydrite into Goethite and Hematite in Alkaline Media
Ferrihydrite Goethite Hematite Morphology Silicate Transmission electron microscopy
2011/11/25
Abstract: The transformation of ferrihydrite to goethite and/or hematite in alkaline media is strongly retarded by the presence of silicate species. These species probably stabilize ferrihydrite by ad...
Effect of Manganese on the Transformation of Ferrihydrite into Goethite and Jacobsite in Alkaline Media
Ferrihydrite Goethite Jacobsite Manganese Phyllomanganate Synthesis Transmission electron microscopy
2011/11/25
Abstract: In the presence of Mn(II), ferrihydrite transforms into Mn-goethite and/or jacobsite. Chemical analysis showed that as much as 15 mole % Mn replaced Fe in the goethite structure. If Mn(III) ...
Photochemical Dissolution of Goethite in Acid/Oxalate Solution
Goethite Iron Lepidocrocite Photochemical dissolution Oxalate
2012/1/11
During photochemical dissolution of goethite in acid/oxalate solution, Fe3+, Fe2+, and CO2 were released and towards the end of the reaction ferrous oxalate precipitated. The dissolution process invol...
Effect of Heating on Microcrystalline Synthetic Goethite
Crystallite size Goethite Microstrain Mossbauer spectroscopy Thermal treatment X-ray powder diffraction
2011/11/25
Abstract: The effect of heating synthetic microcrystalline goethite at 60°, 80°, and 105°C was studied by X-ray powder diffraction, electron microscopy, weight-loss measurements, and Mössbauer sp...
Characterization of Goethite and Hematite in a Tunisian Soil Profile by Mossbauer Spectroscopy
Aluminum Goethite Hematite Iron Manganese Mossbauer spectroscopy Soil
2012/1/12
As part of the characterization of a Tunisian red soil profile, six samples, taken at different depths, were investigated by M鰏sbauer spectroscopy at room temperature and at 80 K to obtain information...