(PDF) Concentrations of critical metals in the Carnmenellis biotite …
In this work, amorphous germanium thin films with different doping elements and concentrations have been investigated by EXAFS spectroscopy. These preliminary results constitute a first answer to ...
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Batch dissolution of granite and biotite in water: …
We performed batch dissolution experiments on different sized granite and biotite in pure water, in order to better understand the source and geochemical behavior of fluoride in groundwater. …
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Eco-friendly natural mineral biotite as a cesium adsorbent: …
DOI: 10.1016/j.chemosphere.2024.141510 Corpus ID: 267889438; Eco-friendly natural mineral biotite as a cesium adsorbent: Utilizing low-concentration acid and hydrogen peroxide. @article{Kwon2024EcofriendlyNM, title={Eco-friendly natural mineral biotite as a cesium adsorbent: Utilizing low-concentration acid and hydrogen peroxide.}, author={Sunki Kwon and …
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In situ observation of biotite (001) surface dissolution at pH …
In this study we investigate the reactivity of the cleaved biotite (001) surface, at pH 1 and pH ca. 9.5, by using in situ flow-through LCM-DIM experiments, combined with phase shifting interferometry (PSI).
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Biotite composition as a tracer of fluid evolution and …
Within the cross-section, the median concentration of Co in biotite located at approximately 2200 m from the deposit center along the westward direction is 5 ppm, whereas adjacent to the center, the median concentration increases to 70 ppm (Fig. 13d). The median concentration of Co in biotite away from the deposit center towards the east ...
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(PDF) pH Effects on Biotite Dissolution Kinetics at Low …
Biotite dissolution rates increased inversely as a linear function of pH in the pH range 3-1, where the rate order n = -0.34. Biotite dissolved incongruently over this pH range, with preferential release of magnesium and iron from the octahedral layer. Release of tetrahedral silicon was much greater at pH 3 than at higher pH.
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Biotite Group – WGNHS – UW–Madison
Biotite refers to a group of common rock-forming minerals forming a series between phlogopite and annite. The name is best used as a field name for dark micas for which the exact composition has not been determined. It is found in a variety of occurrences. It occurs in plutonic igneous rocks ranging from granites to gabbronorite to syenites. Large crystals may form in pegmatites. …
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Insights into the synergistic adsorption mechanism of mixed …
Micro-flotation experiments showed that the recovery of biotite increased to above 90 % upon adding mixed SDS/DDA collectors under the concentration of 5 × 10 −4 mol/L with a molar ratio of 5:1 at alkaline pH (10–11), while that of quartz was below 10 %. The surface tension tests showed that the mixed collectors were easier to absorb on ...
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Arsenic release from biotite into a Holocene groundwater …
Samples were immediately vacuum-packed in O2-impermeable film bags (Escal film, Mitsubishi Gas Chemical Co.) with deoxidizer. After arriving in Japan these were kept in a laboratory freezer ( 18 °C) until analysis. ... As is hosted primarily by biotite or organic matter (>90%) in all of the samples. Lower As concentration in smaller size ...
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Distribution of Minor Elements in Biotite Samples From …
minor element whose concentration in biotite appears to be related to the age of the rock from which it was taken. Biotite from the Precambrian intrusive rock samples generally contains 1 percent or less of this element; biotite from samples of Tertiary intrusives commonly contains 1.5 percent or more. ...
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Potassium at the Origins of Life: Did Biology Emerge from Biotite …
[K +] between mica sheets.Structure of the black mica, biotite. (A) Side view of three biotite sheets, labeled '1', '2' and '3'.(B) Top view of 1 nm 2 biotite, with K + highlighted in the right-hand image, showing that there are six K + per nm 2 between mica sheets.(C) Side view of six mica sheets that are not separated and separated at a distance of 1 nm, where [K +] = 10 M ...
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Adsorption of U(VI) ions on biotite from aqueous solutions
Amounts of 0.4 g of biotite were dispersed in 40 mL NaCl or CaCl 2 (1–100 mM) solutions. A U(VI) concentration of 2 × 10 − 4 M and a size fraction of < 3 mm of biotite were used. Although there is a possibility that U(VI) precipitates at near-neutral pH, higher U concentrations were used for the purpose of U(VI) interlayer adsorption.
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Crystal structures of biotite and muscovite. a) …
Fig. 10 shows the value of the left-hand side of stability conditions Eqs. 8-12, each normalized to the corresponding value at lowest Fe concentration, as a function of Fe concentration.
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Potential of a Nigerian biotite-rich kaolinite ore to …
phosphoric acid concentration increases the fraction of the ore reacted. Fig. 1. X-ray diffraction spectrum of the biotite-rich kaolinite sample. Table 1. Composition of raw biotite-rich kaolinite ...
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Biotite surface chemistry as a function of aqueous fluid …
Taken together, our results indicate that the composition of the biotite surface varies dramatically as a function of pH. At basic conditions, the biotite near-surface is K depleted and likely …
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Les meilleurs films sur les camps de concentration
Liste de 31 films par nouay68. Avec Hamsun, Shoah, Nuit et Brouillard, La Grande Évasion, etc. Découvrez, notez et partagez sur SensCritique. films. ... Actualité. Streaming. Bientôt. Films 2024. Tops. Listes. SensCritique > Nouay68 > Listes > Les meilleurs films sur les camps de concentration. Les meilleurs films sur les camps de ...
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Transformation of carbon tetrachloride in the presence of …
Carbon tetrachloride is transformed in aqueous solutions containing dissolved hydrogen sulfide more rapidly in the presence of the minerals biotite and vermiculite than in homogeneous systems. Approximately 80-85% of the CCl4 was transformed to CO2 via the measured intermediate, CS2. Chloroform comprised 5-15% of the products. The remaining 5% …
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Biotite Mineral Data
Biotite is now a group name for phlogopite, siderophyllite and eastonite. Common world wide. Link to MinDat Location Data. Named in 1847 after the French physicist, Jean Baptiste Biot …
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Biotite as a petrogenetic discriminator: Chemical insights from …
Although biotite Ti concentration has been used as a potential geothermometer for metamorphic rocks (e.g., Henry and Guidotti, 2002; Henry et al., 2005; Chambers and Kohn, 2012), in igneous rocks biotite Ti concentrations are also known to decrease during magmatic fractionation, as Ti-bearing precursor minerals form (Zhang et al., 2016).
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Geochimica et Cosmochimica Acta
concentrations of N will favor N2 stability, while systems with low concentrations of N will favor reduced, single N atom species, for any given PT or ƒO2 condition (Li and Keppler, 2014). This can be demon-strated by expressing the mass action statement for Reaction (1) and rearranging to solve for the NH4 +/N 2 concentration ratio: γ N 2 ...
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Investigation of Biotite with Polarization-resolved White …
In this investigation we combine both methods and semiquantitative approaches to identify two diferent formation stages of the mineral biotite based on its geometrical alignment in the …
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Effect of particle size on leaching of uranium
Effect of three important variables (i.e. pH, pulp concentration, Fe2+ concentration) on uranium leaching was investigated with response surface methodology based on central composite design.
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Insights from mineral trace chemistry on the origin of NYF …
Geology of the Mangodara district. The Mangodara district is situated in the 100 km wide and 500 km long Sideradougou Gneiss and Granitoid Complex (SGGC), located between the Banfora and the Houndé/Ouango Fitini greenstone belt (Fig. 1).The SGGC is dominantly composed of hornblende and biotite-bearing gneiss and granitoids, which contain rafts of amphibolite and …
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Insights into the synergistic adsorption mechanism of mixed …
Effect of pH and collector concentration on the biotite and quartz in the presence of the single collector. ... As shown in the results above-mentioned, a compact and rigid adsorption film was generated when DDA or the mixed SDS/DDA collectors reacted with biotite owning to a lower ΔD value than 1 × 10 −6. Hence, the Sauerbrey model (Equation.
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Biotite dissolution rate data from all closed- and …
Biotite dissolution rates were determined at 25 °C, at pH 2 to 6, and as a function of mineral composition, grain size, and aqueous organic ligand concentration. Rates were measured using both...
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Effects of Na+ and K+ Exchange in Interlayers on Biotite …
Cations in formation brine can affect CO 2-induced dissolution of minerals during geologic CO 2 sequestration (GCS), affecting the GCS performance. This study investigated the dissolution of biotite with 0–4 M Na + and 0–10 mM K + under high temperature and high CO 2 pressure (i.e., 95 °C and 100 bar CO 2).At <0.5 M Na + concentration, Na + replaced K + in the …
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Concentrations
Film Concentration Electives. Students must dedicate three (3) of their MDST electives at the 3000-level or above to courses in which film is the main object of study. These may be chosen flexibly from offerings in Media Studies and the other UVa Departments that offer film courses. The following courses are pre-approved for this requirement.
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Kinetics and Mechanism of Leaching Potassium from Biotite …
The leaching experiments show that leached fractions of K2O increase with the increasing of temperatures and H2SO4 concentrations, and yet with the decreasing of biotite particle sizes.
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Effect of metal ions on the flotation separation of biotite …
As depicted in Fig. 2 (b), as the total collector concentration increased, the flotation recovery of biotite rose before decreasing, and reached the peak of 82.51% at the total collector concentration of 4 × 10-4 mol/L. However, the quartz recovery witnessed a slight increase, plateauing at about 10% as the rise of collector concentration.
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Biotite dissolution at 25°C: The pH dependence of
The rate and stoichiometry of biotite dissolution were studied in the pH range 2–10 using thin-film continuous flow reactors. The release of interlayer K is relatively fast and becomes diffusion-controlled within a few days. The release rates of framework ions (Mg, Al, Fe, Si) are much slower and reach an apparent steady-state within ten days.
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