No. 1688, Gaoke East Road, Pudong new district, Shanghai, China.
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The investigation of stable and radiogenic isotopes and of platinum-group (PGE) and rare earth elements (REE) in chromitites and associated ultramafic rocks of the Kempirsai Massif, southern Urals, gives strong evidence for a multistage formation of giant ophiolitic-podiform chromite deposits present in the southeastern part of the massif. The Kempirsai ophiolite massif is …
In the industrial scale study (Inal et al., 2014) grade and ratio problems of one chromite deposit (M-1) was solved by magnetic separation but the other chromite deposit's (M-2) plant concentrate ...
The United States imports 80 to 90 percent of its refractory-grade chromite from the Philippines, and its basic refractory technology has been designed upon the chemical and physical characteristics of Coto high-alumina chromite ore. ... Thus because nearly all known chromite deposits in the Zambales Complex lie in peridotite near the gabbro ...
The Zambales ophiolite is the major source of chromite ore in the Philippines. The chromitites are concordant cumulates and are associated with distinct chromitite-bearing sequences within the mantle peridotites. Refractory and metallurgical chromite deposits are spatially separated and related to different lithologic associations, which crystallized from different parental magmas ...
Chromite (Cr) occurs exclusively in mafic and ultramafic igneous rocks (Papp and Lipin, 2006).Although some Cr-based minerals such as crocoite (PbCrO 4), vauquelinite (Pb 2 Cu[CrO 4][PO 4]), uvarovite (Ca 3 Cr 2 [SiO 4] 3), and merumite (4(Cr,Al) 2 O 3 ·3H 2 O) are well known, chromite (FeCr 2 O 4) is the only one that is a commercially recoverable source of Cr …
three quarters of the world's viable chromite ore deposits [2], and has an aerial 2extent of 65000 km with thickness of about 7 to 8 km [3]. The BIC consist of western, eastern and the northern limbs. ... be due to depreciation of high-grade chromite seams. Chromite processing involves crushing, milling to less than 1mm and
deposits derived by erosion of such rocks are low in grade and of very minor importance. Extensive nickel-chromium laterites occur in Cuba and Papua New Guinea, but so far there has been no significant production from these deposits. Following Thayer (1960), chromite deposits associated with ultramafic-mafic
Although chromium is a metal, it does not occur naturally in metallic form. Chromium can be found in many minerals, but the only economically significant chromium-bearing mineral is chromite. Chromite has been mined from four different deposit types: stratiform chromite, podiform chromite, placer chromite, and laterite deposits. Most of the world's …
Chromitite is an igneous rock made of the mineral Chromite (FeCr 2 O 4). In this context, a reef is a rock layer enriched in PGE minerals, and is unrelated to sedimentary coral reefs. Principal Bushveld Reef-type deposits: The Merensky Reef …
Chromite is an oxide mineral that an iron chromium oxide with formula: FeCr2O4. It is belonging to the spinel group. Chromite is the most important ore of chromium. Crystals are uncommon, but when found they are octahedral. Chromite is usually massive or in the form of lenses and tabular bodies, or it may be disseminated as granules.
Introduction. Chromite segregations, known as podiform chromite deposits or chromitites, form an integral part of the ultramafic mantle sequence of many ophiolite complexes, particularly where a basal tectonised harzburgite is the dominant lithology (Leblanc & Violette Citation 1983; Roberts & Neary Citation 1993; Zhou et al. Citation 1996).We use the term …
The United States imports 80 to 90 percent of its refractory-grade chromite from the Philippines, and its basic refractory technology has been designed upon the chemical and physical …
The magmatic arc complexes of Indus suture zone includes Jijal complex, Sapat complex and Chilas complex of the Cretaceous age [6]. Chromite deposits in Balochistan are located at Bela ophiolites, Muslimbagh-Zhob, and Waziristan Ophiolites [7]. Figure 1: Location map of reported chromite deposits of Pakistan 2.
However, chromite deposits that are large enough for mining are generally found in: 1) stratiform deposits (large masses of igneous rock such as norite or peridotite that slowly crystallized from subsurface magma); 2) podiform …
The podiform chromite deposit is widely distributed and closely symbiotic with ophiolite, but the scale of this deposit is generally small. There are obvious differences in the occurrence, fabric, structure and paragenetic association of the two different chromite types. The podiform chromite is mainly formed in the Phanerozoic, with a small ...
Chromite, a mineral of the spinel group, is the only commercially viable source of chromium units. Geologically, commercial chromite deposits in the world are found in three forms, i.e. alluvial-, podiform-, and stratiform-type deposits (Murthy et al., 2011; Cramer et al., 2004). Alluvial deposits were formed by weathering of chromite ...
The chromiferous ultramafic rocks of Sukinda Valley (21°0'–21°5'N:85°43'–86°0'E) of Orissa are intrusive into the Iron-Ore Supergroup (2,950–3,200 Ma) at the eastern periphery of the Indian Precambrian shield. …
Exploration models for podiform chromite in the Medford-Coos Bay quadrangles must consider the facts that (1) one deposit occurs for every 5 km 2 of ultramafic outcrop; similarly for a 5 km …
Figure 3. Generalized stratigraphic column of an ophiolite sequence showing the zones with their lithologies and the distribution of podiform chromite (black blebs) (modified after Dickey, 1975; Laurent and Kacira, 1987; and Leblanc, 1987). - "Podiform chromite deposits--database and grade and tonnage models"
Chromite sands from ophiolite chromite deposits, normally used for the metallurgical-grade chromite market, were tested as an alternative starting raw material to produce chromite foundry sands. The study of the silicate impurities assemblage showed that its mineralogy strongly affects the result of the most crucial parameter, the Acid Demand.
Genesis of Low-Grade Chromite Ore Deposits in Lateritic Soils from the Philippines. In: Amstutz, G.C., et al. Ore Genesis. Special Publication of the Society for Geology Applied to Mineral Deposits, vol 2.
Chromite is the most important chromium ore mineral. It forms a complete solid solution series with many other members of the group, eg. in the Chromite-Hercynite Series, Chromite-Spinel Series, Chromite-Magnetite Series and the …
Stratiform chromite deposits are expressed as massive chromitite (greater than 90 percent chromite) bodies or seams of disseminated chromite in large, unmetamorphosed, repetitively …
We have identified 1,124 individual podiform chromite deposits, based on a 100-meter spatial rule, and have compiled them in a database. Of these, 619 deposits have been used to create …
The qualitative assessment used in this study relies on three key criteria: (1) the presence of known deposits, prospects, or mineral occurrences; (2) favourable geologic settings for having ...
The Cr/Fe ratio can thus be used as a proxy for the quality of chromite ore [22]. The lower grade deposits, with low Cr/Fe ratios (i.e., high iron content and low Cr2 O3 content) were as a result not mined. These low-grade deposits have however, been exploited and successfully upgraded using physical methods such as gravity separation [1,4].
the rarity of economic-grade chromite deposits in Ar- chean greenstone belts, though serpentine com- plexes are common. Most minor element concentra- tions are similar to those in the ophiolite cumulate ores, within the limits of compiled data (Fig. 12). Cr/(Cr. AI) 1 0.8 0.6 0.4 0.2 …
Fig. 3. Crudely banded chromite ore in grade 2 quarry (Q2), east of Tata's camp. White bands are altered silicate or serpentine and darker bands are chromite disseminations Fig. 4. Spotted or antiorbicular chromite ore in grade 2 quarry (Q2), east of Tata's camp. White rounded dots are serpentine or talc in the
Exceptionally, some chromite deposits have become a major source of precious metals, among which Pt is the most outstanding resource. Since the sixties, seminal experimental works have demonstrated how the …
This article reviews all the contributions made on genetic aspects of various Indian metallic ore deposits between the period 2020 and 2023. We cover ores of chromite, platinum group elements, gold, uranium-copper ores of Iron Oxide Copper Gold (IOCG) affiliation, rare earth metals (+ niobium + tantalum + yttrium), and lithium-tungsten, the last two being fresh …
