magnetite crystals show variations of the order of 10 to 15 grey levels, while anisotropic sections of hematite reach bireflectance intensities up to 40 grey levels. Fig. 3a. Fisher Linear Likelihood classification of hematite (grey); magnetite (black) and pore (white) pixels based on a stack of five spectral and four polarized images. Fig. 3b.Web
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Magnetite (Fe 3 O 4) shows strong ferromagnetism, and hematite (α-Fe 2 O 3) shows antiferromagnetism with superimposed weak ferromagnetism . Ilmenite (FeTiO 3) is a common mineral in nature and …Web
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Ternary plot of the hematite-ilmenite-magnetite composition of oxide grains based on assumptions and field-cooled remanence experiments. Group 1 (blue squares) has the least variability and is dominated by hematite. Groups 2 (green triangles) and 3 (red circles) have greater variability, with more magnetite than group 1. ...Web
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Here we investigated ilmenite-hematite solid solution (Ilm ss) relationships evident in preserved intergrowths of magnetite-rutile and ilmenite-hematite in the gabbro of the Xinjie layered intrusion. The crystallographic orientation and 3D morphology of the two intergrowth types constrain the transformation mechanism of the exsolution textures ...Web
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hematite and ilmenite belong to the trigonal system, they tend to form a coherent interface in solid transformation (Robinson et al. 2002); in contrast, rutile is tetragonal and magnetite cubic, soWeb
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It is more difficult to distinguish cases where magnetite is mixed with other dark colored minerals, such as hematite and ilmenite. If enough …Web
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The estimated temperature and oxygen fugacity from the magnetite-ilmenite exsolution range from 547.6 to 558.2 °C and from 10−21.4 to 10−21.7, respectively. The data are also consistent with hematite-ilmenite temperature (between 537 and 540 °C) and oxygen fugacity (10−21.7 to 10−21.9) measurements in Cox's Bazar beach placers.Web
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A unique symplectitic intergrowth of magnetite + rutile is hosted by ilmenite in the gabbro of the Xinjie Fe-Ti oxide-bearing, mafic-ultramafic layered intrusion. The …Web
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The ilmenite fraction was composed of three main grain types: homogeneous ilmenite; grains exhibiting complex exsolution of ilmenite in Ti-Hem ss hosts and of hematite or Ti-Hem ss exsolution in ilmenite hosts and hematite. There is a need to refine the beneficiation procedure to separate these three grain types.Web
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Hematite will leave a red to red-brown streak on the plate, while magnetite will leave a black streak. Ilmenite: Ilmenite is a dense, black metallic mineral that can be confused with metallic hematite, but again the two mineral's streak should serve to distinguish them.Web
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Ilmenite and hematite, but no magnetite, are also present in the apatite-actinolite caps at the Maria Ignacia and California apatite mines in the Coastal Cordillera of the Andes in Chile (Tornos et al. 2021). The magnetite in the alkali-calcic-iron alteration also has relatively high TiO 2 contents (see Velasco et al. 2016).Web
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Ilmenite has the ideal composition of FeTiO 3 and a trigonal corundum-type crystal structure [9]. Massive ilmenite is found in lenses and layers, as well as disseminated patterns within igneous anorthosite and gabbro rock complexes. At temperatures higher than about 700°C, ilmenite becomes miscible with hematite (Fe 2 O 3) and vice versa [9].Web
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The most important substitution reactions in upper mantle-derived ilmenite-group minerals exist between ilmenite and geikielite and between ilmenite and hematite (Haggerty 1991). The relations between these end-members are expressed by the simple substitution Fe 2+ ⇔ Mg 2+ (ilmenite ⇔ geikielite) and by the coupled substitution Ti 4+ …Web
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The textural observations of ilmenite–sulfide and ilmenite–titanite–sulfide relationships indicate that Ti-magnetite, in contrast to ilmenite, is an unstable phase in the presence of sulfur ...Web
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Some replacement of magnetite by hematite is noted, but only a minor percentage of the total hematite present has formed in this manner. Ilmenite of one age often exsolves …Web
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Three-dimensional morphologies of magnetite - rutile symplectite in ilmenite. ( a) Typical occurrence of rutile, magnetite, and hematite in ilmenite. ( b) Dendritic rutile and isolated rutile grains, note that the dendritic rutile is interconnected. ( c) Magnetite …Web
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The mineralogical studies point that the ore minerals are represented by hemo-ilmenite, titanomagnetite, ilmenite, magnetite, hematite, and goethite, as well as some specks of pyrite. They usually ...Web
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Ilmenite is an opaque accessory mineral in a wide range of igneous and metamorphic rocks, especially gabbroic varieties, where it is associated with hematite and magnetite as lattice-type intergrowths, and other minerals such as plagioclase and hornblende. Masses of ilmenite were found in several emery mines in the USA, Norway, Canada and Russia.Web
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The solid–solid solution of hematite-ilmenite (1−x)Fe 2 O 3 ·xFeTiO 3 has long been known for its interesting magnetic [1, 2] and semiconducting properties with wide band gaps (2–3 eV) and a change from n- to p-type conduction at x > 0.73 [].Owing to its multifunctional character, the system has attracted a lot of interest for possible spintronic …Web
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Ilmenite, iron-black, heavy, metallic oxide mineral, composed of iron and titanium oxide (FeTiO3), that is used as the major source of titanium. It forms solid-solution series with geikielite and pyrophanite in which …Web
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We performed deformation experiments on dry natural single crystals of magnetite and ilmenite to determine the rheological behavior of these oxide minerals as …Web
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magnetite and hematite with oversize product will be less than 2%. Fig. 2. Fe distribution in size fractions. According to the results of x-ray phase analysis most part of the material is presented by quartz (42.4%) and feldspar (14.6%); valuable minerals were identified as magnetite (14.0%) and hematite (7.8%) as shown in figure 3.Web
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M s of maghemite is therefore somewhat lower than that of magnetite although T C is higher, intermediate between those of magnetite and rhombohedral hematite (αFe 2 O 3). ... Layers of apatite, magnetite, and ilmenite-rich gabbro also occur in the Sept Iles intrusion in Quebec (Namur et al., 2010, 2012). Other ilmenite-rich deposits may be ...Web
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Ilmenite and magnetite are generally termed as Fe–Ti oxides with the idealised formula of FeTiO 3 and Fe 3 O 4, respectively. Two major solid-solution series occur as 'ulvöspinel–magnetite' and …Web
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The titanite-rutile-ilmenite-magnetite symplectites originated between 475 and 700 °C and oxygen fugacities 1.6–1.9 logfO 2 units below the hematite-magnetite buffer. Fluorotremolite associated with diopside and fluorapatite crystallized at temperatures between 710 and 780 °C, and high oxygen fugacities, up to 6 log f O 2 units above NNO ...Web
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The lines denote high temperature solid solutions (ulvöspinel-magnetite, hematite-ilmenite, pseudobrookite-ferropseudobrookite, geikielite-ilmenite, and karooite-armalcolite). The boldened mineral species and highlighted solid solutions are the focus of this study. ... (Fe on ASTIMEX magnetite, Ti on Smithsonian ilmenite) and data …Web
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Haemo-ilmenite samples without coexisting magnetite have natural remanent magnetization to magnetic saturation ratios of only ∼ 2.5%, showing that the …Web
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Ilmenite has an antiferromagnetic (AF) structure with spins parallel and antiparallel to [001] and a Néel temperature of 55–58 K. Note that the periodicity of the …Web
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The hematite formed by the oxidation of magnetite concentrate, which recrystallizes during the roasting process, strengthens pellet consolidation. A long roasting time is required to form and recrystallize a large amount of hematite to prepare high-compressive-strength pellets for low roasting temperature ilmenite concentrate pellet, …Web
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Sri Lanka does not possess massive hard-rock deposits, which typically contain ilmenite, magnetite and hematite. However, such deposits exist in other locations worldwide, including the Allard Lake …Web
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Here we investigated ilmenite-hematite solid solution (Ilm ss) relationships evident in preserved intergrowths of magnetite-rutile and ilmenite-hematite in the gabbro of the Xinjie layered intrusion. The crystallographic orientation and 3D morphology of the two intergrowth types constrain the transformation mechanism of the exsolutionWeb
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In this section, several cases of magnetic techniques for the treatment of typically magnetic ores are introduced, and they are magnetite, hematite, ilmenite, limonite, and nonmetallic ores. In the processing of these magnetic ores, magnetic techniques are applied and their advantages over gravity and flotation methods are well …Web
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Hematite concretion, Two Medicine Formation. Distinctive hematite concretions and titaniferous magnetite mark the transition from the underlying Virgelle Formation to the dinosaur-rich Two Medicine Formation near Bynum, Montana. – Hematite concretion, Two Medicine Formation – Download Free 3D model by callanbentley (@callanbentley) …Web
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Ilmenite, hematite, and a rutile concentrate (LR Rutile) produced from the oil sands tailings (containing mainly leucoxene and rutile), were used in the study. ... (1953) identified four phases (iron, wustite, magnetite and hematite) in samples partially reduced in hydrogen at 650 and 850 °C, and three phases (iron, magnetite, ...Web
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The interactions between magnetite and other iron-rich oxide minerals—such as ilmenite, hematite, and ulvospinel—have been studied extensively, as the complicated reactions between these minerals and oxygen influence how magnetite preserves records of the Earth's magnetic field. Uses. Magnetite is an important ore of ironWeb
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This chapter describes the important iron ore Hematite (abbrv ht), as seen with optical, reflected light microscopy. ... gg—gangue, gth—goethite, il—ilmenite, lpc—lepidocrocite, mt—magnetite, py—pyrite, q—quartz, rt—rutile, tn—tennantite, td—tetrahedrite; 1 General. Important iron ore and, therefore, one of the most ...Web
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Magnetite and ilmenite often occur together in oxide-rich zones of highly differentiated igneous rocks (Ashwal 1982), while magnetite and hematite may occur together in banded iron formations where fluid-present deformation facilitates oxidative transformation of magnetite to secondary hematite (Lagoeiro 1998). At oxidizing …Web
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A unique symplectitic intergrowth of magnetite + rutile is hosted by ilmenite in the gabbro of the Xinjie Fe-Ti oxide-bearing, mafic-ultramafic layered intrusion. The crystallization of rutile in the symplectite is probably formed by oxidation of ilmenite-hematite solid solution (Ilm-Hem ss ). Segregation of Fe 3+ in the Ilm-Hem ss at the …Web
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