Chromite is found as orthocumulate lenses of chromitite in peridotite from the Earth's mantle.It also occurs in layered ultramafic intrusive rocks. In addition, it is found in metamorphic rocks such as some serpentinites. Ore deposits of chromite form as early magmatic differentiates. It is commonly associated with olivine, magnetite, serpentine, and corundum.
Chromite Deposits Allthe chromite deposits inthe U.S.A. arerelatively ~mall and most are of lower grade. Being generally located inAlaska, Montana, Oregon, and California, a further complication istheir distance from consuming plants. Asmost ofthe podiform deposits inAlaska and California contain metallurgical-grade chromite, these ...
An ore is a natural occurrence of rock or sediment that contains sufficient minerals with economically important elements, typically metals, that can be economically extracted from the deposit. The ores are extracted at a profit from the earth through mining; they are then refined (often via smelting) to extract the valuable element, or elements.. The ore grade, or concentration of an ore ...
Box plots of deposit tonnages by podiform chromite deposit subtypes. Dots are values for individual deposits. Median value is the center line of box, 25th and 75th quartiles are top and bottom of ...
grade deposits of the 1970s to lower grade deposits as the demand volume has increased. Traditionally those mined deposits were sourced from thick chromite seams (preferably 2 metres) to reduce the unit mining costs. In addition, a high Cr/Fe ratio in the basic chromitite mineral (3 at the highest) was sought in order to reduce the unit cost of
Both high-grade massive chromite and lower grade disseminated chromite occur in very irregular and unpredictable form in the serpentine, and placer deposits of chromite are in and near streams that drain areas underlain by serpentine.
Chromite. A mineral deposit is defined as a mineral occurrence of sufficient size and grade that might, under the most favorable circumstances, be considered to have economic potential. Deposits sharing a relatively wide variety and large number of attributes are characterized as a "type," and a model representing that type can be developed.
High purity deposits are rare owing to replacement by certain elements. In nature, ferrous iron tends to be partially replaced by magnesium, while chromium may be partially replaced by aluminium or ferric iron. As a result, a range of chromite grades can occur in any deposit, with each grade suitable for a …
Chromite is used as a refractory in the production of steel, copper, glass and cement. Chromite occurs as a primary accessory mineral in basic and ultrabasic igneous rocks. Economic deposits form by crystallisation of chromite from a cooling magma, resulting in large stratiform deposits or smaller pod-like deposits.
What they found instead were the presence of copper and zinc deposits. In 2007, Noront Resources Ltd found high-grade nickel with copper and palladium. This excited mine operators and talk about the Ring of Fire began. Noront and Freewest each discovered notable deposits of chromite as well.
Another major groups of deposits in the mafic layered complexes are platinum group elements and chrome deposits but unlike copper nickel massive sulfides they don't form as puddles on the floor of the intrusions they form in discrete layers well up in the magma chamber. The PGE's that's platinum palladium, rhodium with less amounts of osmium, ruthenium and iridium are often but not ...
near surface location, extensive thicknesses, high grade chrome values and excellent Cr:Fe ratios make these deposits truly world class. Together, these chromite deposits, which are located in the highly prospective Ring of Fire region, total over 200 million tonnes of measured and indicated resources and roughly 50 million tonnes of inferred
In Aladag (Adana, South Turkey) a low-grade chromite deposit (5.42% Cr 2 O 3 grade) with 200 metric tons reserve has yet to be exploited. Chromite demand in Turkey is mostly met by metallurgic-type ores. Chromite ore is one of Turkey's major income sources in primary mineral exports.
As a result, a range of chromite grades can occur in any deposit, with each grade suitable for a specific application. Grades produced include metallurgical and non-metallurgical applications: · Metallurgical grade (high chromium chromite, minimum 40% Cr 2 O 3) · Chemical grade (high iron chromite…
Chromite ((Mg, Fe ++)(Cr, Al, Fe +++) 2 O 4) is the only source for the metallic element chromium, which is used in the metallurgical, chemical, and refractory industries.Podiform chromite deposits are small magmatic chromite bodies formed in the ultramafic section of an ophiolite complex in the oceanic crust.
As you can see in the example above, the deposit does not have to be enormous in size (only 500 meters long by 100 meters wide) to contain a valuable deposit (approximately $6 billion worth of minerals). However, in order to be as realistic as possible about this valuation, you can not assume that the complete ore body contains the same grade (i.e. 2% copper and 1.5 gram per tonne gold).
The largest chromite deposit reported was between 5 to 25 feet wide and 250 to 300 feet long. The chromite of the Sheridan deposits is somewhat lower in grade than those of the Red Lodge area; reported Cr 2 O 3 content of clean chromite ranges from 38 to 45 percent, and Cr:Fe ratios range between 0.8:1 and 1.3:1.
Subtype of podiform chromite deposit as determined by the grade and tonnage models. Textual values of no more than 15 characters. tectset Paleotectonic setting. Paleotectonic setting, a preliminary categorization of the deposit according to the tectonic setting in which the deposit formed, midocean ridge, off-ridge, or suprasubduction.
Their near surface location, extensive thicknesses, high grade chrome values and excellent Cr:Fe ratios make these deposits truly world class. Together, these chromite deposits, which are located in the highly prospective Ring of Fire region, total over 200 million tonnes of measured and indicated resources and roughly 50 million tonnes
2 Podiform Chromite Deposits—Database and Grade and Tonnage Models selected are considered well studied, with detailed deposit . descriptions, maps and sections of ore bodies, and production or reserve data for most of the podiform chromite deposits.
Chromite within both the Upper and Lower zones averages less than 5 pct Cr2O3 across the total width; however, most of the chromite is concentrated in the discrete layers and schlieren. These schlieren consist of subparallel high-grade bands of chromite (45 to 50 pct Cr2O3) bounded by nearly barren dunite (1 to 2 pct Cr2O3).
Chromium (Cr) has a wide range of uses in metals, chemicals, and refractories. It is one of the Nation's most important strategic and critical materials. Chromium use in iron, steel, and nonferrous alloys enhances hardenability and resistance to corrosion and oxidation. The use of chromium to produce stainless steel and nonferrous alloys are two of its more important
Where are the world's top nickel deposits located? ... In terms of high-grade resources, Indonesia's in-situ nickel laterite inventory is the largest globally, and the second highest grade after New Caledonia, according to information published on Direct Nickel's website. The laterites are mostly present in Sulawesi and Halmahera.
Chromite is the only commercial source of chromium. It occurs as a primary mineral of ultrabasic igneous rocks and is normally associated with peridotite, pyroxenite, dunite and serpentinite. Worldwide, high-alumina chromite, lar gely from podiform deposits, is used in refractory applications while iron-rich ores, largely from stratiform deposits,
The Fe-dominant species - chromite itself - can be FOUND, although uncommonly, in many "chromite" deposits, chromitite (rock name), and other "chromite"-bearing occurrences connected with hyperbasic rocks. As a rule of thumb, a member of the chromite-magnesiochromite series is twice as likely to be a magnesiochromite instead of a chromite.
Start studying Economic Minerals/Ore Deposits. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Search. ... Lowest grade ever mined (0.5% Cu) only worked at times of high metal prices ... Chromite deposits. Chromite. One of the first minerals to form
Oct 16, 2016· CHROMITE ORE DEPOSITS IN EGYPT 1. LECTURE 2: Hassan Z. Harraz [email protected] 2016- 2017 @ Hassan Harraz 2017 2. Outline of Lecture 2 We will explore all of the above in Lecture 2. Introduction Tectonic evolution of the CED Distribution of the ophiolite in Egypt Chromite Host Rocks Chemistry Ore Types Mineralogy Origin
possibility of larger cumulate-style chromite deposit being present. Using a cut-off grade of 2.5% chromite, an indicated lateritic resource of almost 6.9 Mt at 4.31% chromite has been defined, although the feasibility of extracting chromite ore and other metals is unknown (Noble Resources NL 1994). Mapping by the Geological Survey of New South