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 describe the interface of the reacting oxide. Adsorption of both S2O 4 2− (D) and complexant (L) generates three surface complexes that define the …

On the other hand, Joshi et al. demonstrated distinct anisotropic morphological changes in goethite crystals due to the preferential etching of tips (i.e., the (210) and (234) crystal …

Table 1 Relative abundances of Sc measured by ICP-AES and EDX/TEM.. Figure 1 X-ray diffractograms for goethite, ScOOH and Sc-doped goethite samples.. Figure 2 Top: Changes in cell parameters and in cell volume as a function of rate of substitution of Fe by Sc (numerical data for cell parameters and errors can be found in SI). Dashed lines …

The study of the extraction of Re% As(Ill) 100" 80" 60" 40 20 G---~ D Goethlto (oIL)r 0 I 3 5 9 11 13 pH Fig. 4. Sorption of As(III) on goethite (contact time 30 min), at two different sorbent concentrations. pollutants using novel inorganic ion exchangers (of synthetic or natural origin), is considered to be an innovative research field.

Dithionite as a Dissolving Reagent for Goethite in the Presence of Edta and Citrate. Application to Soil Analysis - Volume 40 Issue 5 ... Departamento de Química e Ingeniería Química, Universidad Nacional del Sur, Avenida Alem 1253, (8000) Bahía Blanca, Argentina ... 1991 Extraction of iron oxides from sediments using reductive dissolution ...

Goethite has weak saturation magnetization and very high coercivity (Hedley, 1971; Rochette and Fillion, 1989). It dehydrates to hematite at about 300°C. Goethite is an important product in low-temperature oxidation, particularly of iron sulfides, and is a constituent of manganese nodules and of the Pacific red clay facies, where it may ...

In this study, batch experiments were performed to quantify the Pb extraction from goethite by EDTA and EDDS, respectively, and attenuated total reflectance-Fourier transform infrared (ATR/FT-IR ...

Trans. Nonferrous Met. Soc. China 32(2022) 3077âˆ'3087 Enhanced conversion mechanism of Al-goethite in gibbsitic bauxite under reductive Bayer digestion process Guo-tao ZHOU, Yi-lin WANG, Tian-gui QI, Qiu-sheng ZHOU, Gui-hua LIU, Zhi-hong PENG, Xiao-bin LI School of Metallurgy and Environment, Central South University, Changsha …

The acetate extraction dissolved most of this high-coercivity phase as well as some pyrrhotite and goethite. The dithionite extraction effectively solubilized the remainder of these two phases although a small amount of pyrrhotite remained and was slightly dissolved during the oxalate extraction. See Figure 2 caption for abbreviations.

Goethite exhibits grey color and forms as an alteration product after magnetite and pyrite (Fig. 12 E). Goethite showing typically under oxidizing condition as a weathering product of iron bearing minerals, such as: magnetite, pyrite. Goethite most typical habits are as porous bands with radiating fibrous or as porous pseudomorphs after pyrite.

The aim of this study was to precipitate goethite from high-iron(II)-bearing atmospheric and heap leach solutions of lateritic nickel ore generated either by reductive leaching of the ore or by reducing Fe(III) of the leach solution to Fe(II) using a suitable reducing agent and to understand the Ni and Co losses during the iron precipitation. Removal of Fe was …

The conversion of Al-substituted goethite (Al-goethite) to hematite in gibbsitic bauxite is conducive to alumina extraction during the Bayer process and the enrichment of iron minerals in red mud. In this work, mineralogical characteristics of gibbsitic bauxite were identified by AMICS analysis, and …

A reactor model has been built to simulate the goethite process for iron removal. A three-factor designed set of boundary conditions was applied to determine the effect of stirring …

The current study aimed at investigating the sorption mechanisms of DPAA on ferrihydrite, goethite and hematite using both macroscopic sorption kinetics and sequential extraction procedure (SEP) as well as microscopic Fourier transformed infrared (FTIR) and extended X-ray absorption fine structure (EXAFS) spectroscopic techniques.

Request PDF | On Mar 1, 2019, Meng Zhu and others published Sorption mechanisms of diphenylarsinic acid on ferrihydrite, goethite and hematite using sequential extraction, FTIR measurement and ...

Scandium (Sc) is the lightest of REE. It has atomic number 21, thus being the neighbor of calcium (Ca). Unlike calcium, which is the fifth most abundant element in the Earth's crust, Scandium is scarce, but still more abundant than lead, tin, silver etc. Scandium has the electron configuration [Ar]3s 2 3d 1.This immediately indicates that the sole oxidation …

Request PDF | Selective extraction of amorphous iron oxide by EDTA from a mixture of amorphous iron oxide, goethite, and hematite | Iron (III) was extracted by EDTA and ammonium oxalate from a ...

Iron ore with significant goethite content can be processed to extract iron and used in the production of steel and other iron-based products. Catalysis: Goethite nanoparticles have shown promise as catalysts in various chemical reactions. Their high surface area and reactivity make them useful for catalyzing oxidation and reduction reactions ...

Goethite coated with aluminium on its surfaces is known to reduce adsorption ... González F. Mercury extraction from cinnabar ores using hydrobromic acid: previous studies. …

Goethite (FeO2H) can also occur in iron ore formations due to the hydration of other ironbearing species. In flotation and pelletization, goethite behaves well if accounted for as it has good ...

The ideal case of P-extraction from goethite ore by these naturally existed alkaline-tolerant microorganism was expected to be: microorganisms can extract phosphorus for its own use, meanwhile, alkaline medium can dissolved some phosphorus and those dissolved phosphorus would not be absorbed back to goethite under the slightly alkaline ...

The conversion of Al-substituted goethite (Al-goethite) to hematite in gibbsitic bauxite is conducive to alumina extraction during the Bayer process and the enrichment of iron …

Dithionite-citrate-bicarbonate (DCB) treatment is a classical method for removing iron oxides from soil. The DCB-induced dissolution effects on iron oxides are controversial. In this paper ...

1 Introduction. The dissolution of (nano)materials is of great interest to investigate to a wide range of research fields, including climate and atmospheric CO 2 storage associated with rock erosion, [1-3] agricultural nutrient release strategies, [] bioweathering in ecology, [] energy storage in batteries, [] and corrosion science [] involving biomaterials, [] but also …

FT-IR spectra of the synthesized goethite mineral (Fig. 2) show very broad IR band at 3174.1 cm −1, which can be attributed to the stretching vibration of surface H 2 O molecules.The characteristic sharp bands at 798.0 cm −1 and 892.4 cm −1 can be …

Goethite [FeO(OH)], the surface of which we modified by thin coatings of hydrophobic quaternary amines, has been used to extract the perrhenate anion (ReO 4)- from alkaline aqueous solutions (pH 11.3).The quaternary amines were bound to the surface of the goethite by ionic association between the negatively charged inorganic surface and the …

maximum alumina extraction Guotao Zhou, Yilin Wang,* Tiangui Qi, Qiusheng Zhou, Guihua Liu, Zhihong Peng and Xiaobin Li* The conversion of Al-substituted goethite (Al-goethite) to hematite in gibbsitic bauxite is conducive to alumina extraction during the Bayer process and the enrichment of iron minerals in red mud. In this

The results showed that after precipitation of iron, Zn extraction of 88.5% was obtained with the 2 stages extraction system composed of 30 vol% D2EHPA as extractant. The overall Zn recovery from ...

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The effect of mineralogy and texture on the beneficiation of goethitic ores from two different origins is highlighted. Sample A having 54.47% Fe with 8.57% loss of ignition (LOI) …

Cela nous a permis de proposer trois hypothèses probables de transformation topotactique : GR→l e ́ pidocrocite; WR→goethite et l e ́ pidocrocite→goethite Ces hypothèses de transformation sont en bon accord avec les résultats expérimentaux concernant la préparation des oxy-hydroxydes de fer.

a 24-h extraction with 1 N HCl at room tem- perature and extraction with dithionite leach comparable amounts of Fe, even though lep- idocrocite, goethite, and hematite are dis- solved with dithionite and are not attacked by 1 N HCl (Table 1). Acknowledgments

Extraction of arsenic (As) from adsorbed (ad) and coprecipitated (cpt) As-Fe(OH) 3, As-Fe 3 O 4 using phosphate buffer, sodium hydroxide (NaOH), hydrochloric acid (HCl), and oxalate buffer was studied. In addition, the effects of the solution concentrations, sample drying, aging time, and goethite and fresh As-Fe(OH) 3 (cpt) mixture on the extraction …

Preparation and evaluation of functionalized goethite nanorods coated by molecularly imprinted polymer for selective extraction of bisphenol A in aqueous medium. ... Goethite is one of the most common and thermodynamically stable iron oxide in sediments and natural systems. This mineral due to their rode-like morphology provide high surface-to ...

Abstract. The sorption kinetics of antimony(V) on synthetic goethite is very fast compared to the sorption of other metals on goethite (e.g. arsenic and selenium) and depends on temperature, with an activation energy of 49±9 kJ · mol −1 in the temperature range 15–35°C. Sorption isotherms have been developed at different temperatures and ionic …

Sometimes, goethite contains a high content of phosphorus (P) and the existing phosphorus removal techniques is to thermally roasted the ore with or without alkaline additives followed by chemical ...