magnetite iron extractable

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magnetite iron extractable

Iron mineral dissolution releases iron and associated organic …

The amount of reactive iron minerals in the transition zone then decreased to 11.1% of the total extractable iron in the bog (2.1 ± 0.1 mg reactive Fe per g soil in comparison to 18.7 ± ...

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Selective dissolution of Fe–Ti oxides — Extractable iron as a …

Few studies (Rhoton et al., 1981, van Oorschot and Dekkers, 2001, van Oorschot et al., 2002, Walker, 1983) assessed the effects of magnetite on oxalate and DCB extractable iron. It was demonstrated that oxalate extraction preferentially dissolved fine grained magnetic Fe oxides from both, synthetic and natural samples.

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Magnetite accelerates syntrophic acetate oxidation in …

These results implied that (i) the re-suspension pretreatment had almost removed the endogenous methanogenic substrate in the sludge; (ii) magnetite did not facilitate methanogenesis from acetate as an …

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Formation of magnetite-(apatite) systems by crystallizing …

High fluid-phase pressures produced during massive crystallization of magnetite from the melt further facilitate the exsolution of magmatic-hydrothermal fluids responsible for the formation of aureoles of alkali-calcic-iron alteration with …

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Selective dissolution of Fe–Ti oxides — Extractable iron as a …

Oxalate extractable iron (Fe o ) content reaches 4e5% of the total iron for samples from the uppermost level (2 cm depth) and at an 82-cm depth. ... (Table S5); this is much lower than the 0.08 to ...

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To determine the effects of extraction conditions on the redox and electron-shuttling properties of SOM extracts, we prepared HA, FA, and water-extractable organic matter (OM) extracts, applying either a combination of 0.1 M NaOH and 6 M HCl or ultrapure water (pH 7), from soil samples collected from the subsoil (0–15 cm, A horizon, pH 6.5 ...

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Weathering of Iron-Bearing Minerals in Soils and Saprolite

The weathering products of primary biotite, chlorite, magnetite, and almandine in mica gneiss and schist in the North Carolina Blue Ridge Front were determined. Sand-size grains of biotite, the most abundant, readily weathered mineral in the parent rock, have altered to interstratified biotite/vermiculite, vermiculite, kaolinite, and gibbsite in the …

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Frontiers | Intrinsically Magnetic Cells: A Review on Their Natural

A schematic depiction of SQUID graphs and their extractable magnetic information is given in Figure 2E. For example, variation in temperature allows ... of the loop match the distance between iron cations in magnetite (Nudelman et al., 2016) and in vitro studies on MamC and protein constructs that contained the helical MamC loop resulted ...

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Geochemical and mineralogical constraints in iron ore tailings limit

The present study aimed to characterize key physico-chemical and mineralogical attributes of magnetite iron (Fe) ore tailings to identify potential constraints limiting in situ soil formation and direct phytostabilization. ... CBD-extractable Fe/Al should include oxides and hydroxides of Fe (e.g., hematite, goethite, lepidocrocite and maghemite

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Magnetite | Magnetic Properties, Iron Oxide, Magnetism

For detailed physical properties, see oxide mineral (table). This article was most recently revised and updated by Amy Tikkanen. Magnetite, iron oxide mineral (FeFe2O4, or Fe3O4) that is the chief …

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Sorption of Bioavailable Arsenic on Clay and Iron Oxides

In this study, the effects of As-contaminated groundwater by various minerals in the soil were evaluated. The influence of As on microbial inhibition and activities influenced by soil minerals such as clay minerals (bentonite and kaolinite) and iron oxides (hematite, goethite, and magnetite) were investigated. The method used to evaluate the …

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Siderite-based anaerobic iron cycle driven by autotrophic

Growth of thermophilic bacteria based on two low-energy reactions of siderite oxidation and magnetite reduction makes the fugacity of CO 2 a master switch of this short iron cycle, either ...

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Magnetite: South Australia's potential | Energy & Mining

The iron oxide mineral magnetite as Fe 3 O 4 has a mass percent of 72.36% Fe and 27.64% O and typically occurs as a natural ore containing 15–40% Fe. Historically hematite direct shipping ore (DSO) has been the preferred source of iron ore globally, with significant resources located on several continents, including Australia in the Hamersley Range, …

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chapter 15 planet earth Flashcards | Quizlet

phosphate, pumice, gypsum, slate, limestone. Which of the following metals is both a precious metal and a strategic mineral? platinum. Which characteristics are essential to defining a geologic occurrence as an ore deposit? It has a high concentration of a metal. It contains enough ore to make mining economical.

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Magnetite & Lodestone | Mineral Photos, Uses, Properties

Pyrrhotite is the second most common magnetic mineral. It can easily be identified by its magnetic properties, lower hardness, and bronze color. Lodestone: A specimen of lodestone that has attracted numerous tiny particles of iron. This specimen is approximately 10 centimeters across. Magnetite Crystals: Octahedral crystals are a common crystal ...

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Humic acid impacts antimony partitioning and speciation during iron…

The observed decrease in the PO 4 3−-extractable fraction of solid-phase Sb in these treatments (Fig. 5) suggest gradual desorption of Sb from the surface sites of ferrihydrite. At pH 8, Fe(II) prompted the transformation of Sb(V)-coprecipitated ferrihydrite to goethite, magnetite and lepidocrocite under both HA-free and HA-rich conditions.

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Magnetite biomineralization in ferruginous waters and early Earth

Magnetite forms raspberry-like, framboidal grains through microbial iron reduction in the water column of two ferruginous lakes. ... (Fe HCl, 0.5 N HCl extractable Fe), ferric (oxyhydr)oxides including hematite and goethite (Fe Dith, dithionite extractable Fe), and magnetite (Fe Oxa, oxalate extractable Fe). The non-reactive, ...

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Prediction of reducible soil iron from iron extraction data

Dithionite extractable Fe was determined by adding 4.8 ml 50 g/l sodium dithionite. in 0.35 M acetic acid/0.2 M sodium citrate at pH = 4.8 to 0.2 ml slurry sample. Total Fe extraction was done by ...

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Magnetite | Common Minerals

Magnetite is a black, opaque, magnetic mineral that leaves a black streak when rubbed across a hard rough surface. It is one of the most abundant metal oxides, and its crystal structure contains both the ferrous (Fe+2) and ferric (Fe+3) forms of iron ions. A complex pattern of electrons between the two forms of iron is the source of its ...

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Selectivity of reagents used to extract iron from soil

The selectivity of the Tamm and Mehra-Jackson reagents to iron (hydr)oxides was verified chemically by comparing the efficiencies of the two methods of iro ... L. D. Norton, and N. T. Smeck, "Contribution of Magnetite to Oxalate-Extractable Iron in Soils and Sediments from the Maumee River Basin of Ohio," Soil Sci. Soc. Am. J. 45(3), 645 ...

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The Effects of Magnetite on Oxalate‐ and Dithionite‐Extractable Iron

Magnetite should be left in the samples to be treated by the dithionite extraction, but the concentration of magnetite in the soils should be noted. In order to get the best possible estimation of relative age using free Fe concentrations, the ratio of magnetite-free oxalate to dithionite-extractable Fe should be used.

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University of Nebraska

encing microbial reduction of iron oxides through formation of (1) aqueous complexes and/or (2) ferrous solids that suppress sorption and act as alternative Fe(II) sinks to the oxide or organism surface. Scientiﬁc information supporting such spec-ulation, however, is limited. Magnetite and siderite are frequently observed products of

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(PDF) Iron reduction in the sediments of a hydrocarbon …

Fines were removed the Fe in magnetite was removed. Iron removal from by ultrasonic cleaning and rinsing with deionized nontronite was similar to the 0.5 M HCl extraction. water. ... (1999) 655±667 Mean concentrations for Ti-CEB-extractable iron lations by Bennett et al. (1993) that Fe(III) is precipi- (FeTi-CEB) support the measured depletion ...

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DCB dissolution of iron oxides in aeolian dust deposits

DCB dissolution of iron oxides in aeolian dust deposits controlled by particle size rather than mineral species | Scientific Reports. Dithionite-citrate-bicarbonate (DCB) treatment is a...

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Richard P. Blakemore's research works | University of New Hampshire

Redox Cycling of Iron Supports Growth and Magnetite Synthesis by Aquaspirillum magnetotacticum ... The fluid contained ادامه مطلب

Mineral and Technological Features of …

The main Fe-bearing mineral in the samples is hematite, which contains 65.09% of the iron in the samples. The share of …

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Phosphate modified magnetite@ferrihydrite as an

The morphological properties of the samples were analyzed using SEM and STEM. The SEM image showed that the magnetite particles have irregular shape and smooth surface (Fig. 1 B).After reacting with HCl, corrosion of magnetite caused many observable cracks on the surface (Fig. 1 C).As for Mag@Fh-P, a layer of nano-sized …

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Effect of citrate-bicarbonate-dithionite treatment on fine-grained

In general, little additional iron is removed by additional extractions or washings [10]. In order to monitor the progress of the CBD procedure, we subdivided the extraction procedure used in this study. Initially, 200 mg samples of the sized magnetite grains were dispersed by hand in 4.0 g of acid-washed sand (0.1-0.5 mm grain size).

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Assessing poorly crystalline and mineral-organic

Iron extraction from the minerals, apart from pyrite, by citrate was negligible (≤2% of total Fe), like from Fe oxides (≤1.5% of total Fe), while oxalate-extractable Al, Fe, and Mn contents were larger than those extracted by CA, the relative fraction of which was below 9%, except for allophane.

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Microbial interspecies electron transfer via electric currents

this, concentrations of 0.5 N HCl-extractable iron were measured throughout the incubations (Fig. S1). This analysis revealed that 2–2.5 mM acid-extractable iron was present in the hematite- and magnetite-supplemented cocultures and in the G. sulfurreducens single cultures. In the cocultures, most of acid-extractable iron

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