Chromium (Cr) Ore | Minerals, Formation, Deposits
Chromite is a dark, opaque mineral with a high specific gravity and metallic luster. It is typically found in the form of euhedral crystals, irregular grains, or as interstitial material between other minerals in the host rock. Chromite is composed of chromium, iron, and oxygen, with variable amounts of magnesium, aluminum, and other elements.
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Chromite | Ores, Mining, Processing | Britannica
Chromite, relatively hard, metallic, black oxide mineral of chromium and iron (FeCr2O4) that is the chief commercial source of …
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Chromosome
The end result is organisms that function and behave in different ways. This variation allows populations to evolve over time, in response to changing environments. Function of a Chromosome. The …
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Determination of Breakage Distribution Function of fine chromite …
PDF | On Oct 10, 2012, H. Hosseinzadeh and others published Determination of Breakage Distribution Function of fine chromite ores with Bed Breakage Method | Find, read and cite all the research ...
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Application of chromite sand in foundry industry
CHROMITE SAND. Application of chromite sand in foundry. 1. Chromite sand has excellent cooling performance. It does not reduce hot cracks, but can affect the temperature gradient and promote directional solidification without using cold iron. 2. Chromite sand is inert, so it does not react with other metal oxides. It will not be wetted …
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Thermodynamics of chromite ore oxidative roasting process
To explicate the thermodynamics of the chromite ore lime-free roasting process, the thermodynamics of reactions involved in this process was calculated and the phrases of sinter with different roasting times were studied. The thermodynamics calculation shows that all the standard Gibbs free energy changes of the reactions to form …
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Chromite: The only mineral ore of chromium …
Chromite is the only ore of chromium, a metal essential for making stainless steel, nichrome, chrome plating, pigments, refractories, chemicals and pharmaceuticals.
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Flotation recovery of chromite (using SO, SDS and CTMAB …
Chromite is an important strategic mineral usually associated with other gangue minerals, mainly silicates. A good knowledge of the flotation behaviour of chromite and the establishment of ...
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Reduction of roast Movat chromite ore with carbon
Solid-state reduction of roast Movat chromite ore with carbon was carried out as a function of the C/FeO ratio at temperatures ranging from 800 °C to 900°C. The reduction was studied using thermogravimetric analysis (TGA). A two-stage mechanism consisting of the reduction of FeO with carbon monoxide and the regeneration of CO by …
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Chromite Flotation
Flotation recovery of chromite as a function of pH at constant SDS concentration 1 x 10 -4 M is shown in figure 2. The four separate curves of the figure demonstrate the effect of aging of dry chromite that had been ground to flotation size (100/150 mesh) on subsequent flotation behavior. The fresh
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Photocatalytic degradation and photo-Fenton oxidation of …
Refined natural Fe-chromite was characterized by XRD, FT-IR, reflected polarized microscope, XRF and UV spectrophotometer. Photocatalytic degradation and photo-Fenton oxidation of Congo red dye by Fe-chromite was investigated using 1 mL H2O2. The degradation of dye was studied as a function of illumination time, chromite …
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Determination of Breakage Distribution Function of fine …
1 Determination of Breakage Distribution Function of fine chromite ores with Bed Breakage Method H. Hosseinzadeh1,*, L. Ergün2, 1 Mining Engineering Department, Hacettepe University, Beytepe ...
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The Mineral chromite
Chromite, the principle ore of the element chromium, is a commercially valuable mineral. However, due to mining restrictions and the fact that Chromite is not commonly found in …
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Thermodynamic Modeling of the Solid State …
Chromite ore is added along with a carbon-containing reducing agent and a flux, typically silica and then smelted in the SAF. This process is very energy intensive, ... carbide phase is a function of the availability of carbon during reduction. For carbon-rich conditions, Cr 7C 3 is formed, while for carbon-poor conditions, Cr 23C 6
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21.7A: Chromium Metal
Chromite ((ce{FeCr2O4})) is the most commercially useful ore, and is extensively used for extraction of chromium. Chromium is produced in two forms: Ferrochrome by the reduction of chromite with coke in an electric arc furnace. A low-carbon ferrochrome can be produced by using ferrosilicon instead of coke as the reductant.
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Minerals | Free Full-Text | An Overview of Currently Applied …
Compared to raw chromite, oxidized chromite consumes less energy during smelting as the chromite spinel has been altered during exposure to elevated temperatures . Additionally, the partial oxidation of chromite pellets improves the extent of pre-reduction that can be achieved in the upper section of an SAF before liquid …
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Fractal evaluation of particle size distributions of chromites …
The D F for each chromite ore was obtained by first developing an M(X < x)/M T versus x/X L on log–log plots and determining the slope of the best-fit line through the data points using linear regression. The measured data points showed an appropriate pattern of linearity on the M(X < x)/M T versus x/X L plots as seen in Fig. 2, Fig. 3, Fig. …
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New model of chromite and magnesiochromite
The chromite fraction was then separated from secondary silicates (e.g., serpentine) manually. After extraction of the chromite fraction, the chromite grains were leached using 6.2 N HCl and 5% HF, following the method of Snow et al. (1994). First, chromite was maintained in the leaching solution for 10 minutes, then the solution was removed.
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A Comparative Study on PSD Models for Chromite Ores Comminuted …
The objective of this study was to characterize the particle size distributions (PSDs) of chromite ores comminuted by different devices, i.e., subjected to different breakage modes and to compare ...
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Chromite | Earth Sciences Museum
Chromite is the main source of the metal chromium, a metal used to induce hardness, toughness and chemical resistance in steel. It was named after its chemical …
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Flotation of chromite and serpentine
Following the same rationale, the modifying action of fluorosilic acid as function of pH, as well as the effect of its concentration during chromite and serpentine flotation using sodium oleate as collector are presented in Fig. 6, respectively. FSA seems to be an effective medium for selective separation of chromite from serpentine.
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THERMODYNAMIC EFFECTS OF TEMPERATURE DURING ROASTING OF CHROMITE …
chromite roasting as a function of temperature increase. Thus far, the formation of NaCrO 4 2-ions remain hy-pothetical, however performing the leaching experi-
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Thermodynamic Modeling of the Solid State Carbothermic Reduction …
Reduction of chromite by carbon has been studied by several researchers [19,20,21,22,23,24]. It appears that the composition of the carbide phase is a function of the availability of carbon during reduction . For carbon-rich conditions, Cr 7 C 3 is formed, while for carbon-poor conditions, Cr 23 C 6 will be formed.
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Isothermal oxidation kinetics of industrial South African chromite …
The rate of a solid-state reaction can then be defined by the following general equation: (2) d α dt = A exp-E RT f (α) where f(α) is a function describing the reaction model that depends on the reaction mechanism (Gotor et al., 2000), E the activation energy, A the pre-exponential Arrhenius factor, R the universal gas constant and T the …
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Chrome ore beneficiation challenges & opportunities – A …
In the current research, the permittivities of various mixtures of several pyrometallurgical raw materials plus carbonaceous reducing agents were determined as a function of both temperature and frequency, using the cavity perturbation technique. The raw materials investigated were an oolitic iron ore, an electric furnace dust and a …
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Flocculation-dispersion behavior of chromite and serpentine …
Download scientific diagram | Flocculation-dispersion behavior of chromite and serpentine as a function of pH from publication: Selective flocculation behavior of chromite and serpentine ...
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The entropy of zinc chromite (ZnCr2O4) | Semantic Scholar
Abstract The low-temperature heat capacity of zinc chromite (ZnCr2O4) was measured between 6.5 K and 400 K using adiabatic calorimetry, and some thermochemical functions (CP(T), S(T), Sº298, H(T)-H(0)) were derived from the results. The standard entropy (Sº298 = 128.6±0.3 J mol-1 K-1) for zinc chromite was calculated from the …
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Reduction degree of mixture "chromite ore
Download scientific diagram | Reduction degree of mixture "chromite ore + mill scale + carbon" as a function of time: a comparison among the completely reduced powder samples and the disc ...
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