Detailed gravity surveys were made in Camaguey Province, Cuba, as part of a systematic exploration program conducted by the U. S. Geological Survey on behalf of the General Services Administration to locate deposits of refractory-grade chromite. During the period August 4, 1954, to April 5, 1956, a total of 41,921 gravity stations were established in nine areas …
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 …
This paper reviews the ~ajor deposits of lower-grade chromite in the world, and a wide variety of methods used for the recovery of ch.romlum f~om them. Ga~gue materials in more coarsely sized ores can be separated by gravity ~ean~, whereas flotation techniques are required for finer-grained materials. However, unless there is considerable
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Most deposits contain a range of chromite grades, including: Metallurgical grade (high chromium chromite, minimum 40% Cr2O3) ... Chemical grade chromite is used in leather tanning, metal finishing, wood preservatives, light-stable and corrosion-inhibiting pigments, paints, coloured glass and ceramic glazes. ...
Chromite Deposits Along the Border Ranges Fault, Southern Alaska (In Two Parts) 1. Field Investigations and Descriptions of Chromite Deposits ... roads and all deposits containing only chemical- or refractory-grade chromite, about 2,200,000 tons of Cr203 are contained in 41 hard-rock deposits. A placer deposit contains an additional 556,000 tons.
Chromite : FeCr 2 O 4; Types of chromite deposits :-High grade ore with very low iron-oxide. Ex- Sukinda-Nausahi (Cr :Fe =3:1) Aluminous chromite with Fe 2 O 3 more than 20% but less than 30%. Ex- Kondapalli (AP) (Cr :Fe =2:1) Ferriferous chromite with Fe 2 O 3 more than 30% . Ex- Jojohatu (Bihar) Siliceous chromite with high SiO 2 content
Of these, 619 deposits have been used to create three new grade and tonnage models for podiform chromite deposits. The major podiform chromite model has a median tonnage of 11,000 metric tons and a mean …
Location and characteristics of 1,124 individual mineral deposits of this type, with grade and tonnage models for chromium as well as several related elements. Search Search. Mineral …
Units are thousand metric tons, gross weight, of marketable chromite ore. 15. See Appendix C for resource and reserve definitions and information concerning data sources. 16. Units are thousand metric tons of shipping-grade chromite ore, which is deposit quantity and grade normalized to 45% Cr. 2. O. 3, except for the
sible deposits of high-grade chromite have been worked out, and future production will be predominantly from low-grade concen trating ore containing from 15 to 30 percent of chromic oxide (CrgOj). The known reserve in the explored deposits is about
Chromite ((Mg, Fe++)(Cr, Al, Fe+++)2O4) 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. These deposits have been found in midoceanic ridge, off-ridge, …
higher metamorphic grade. SEIAD CREEK CHROMITE DEPOSITS LOCAL GEOLOGY The Seiad Creek chromite deposits in the northwest quarter of the Seiad Valley quadrangle occur in two tabular ultramafic bodies, one a dunite, the other an harzburgite. The two bodies are ...
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 …
COMMENTS All deposits in this grade-tonnage compilation are from California and Oregon. The two ... based on reported analyses of samples from the deposits. chromite grade (r = 0.76, n = 12) and iridium grade (r = 0.71, n iridium grade (r = 0.88, n = 7).See figs. 24-26. Name Bagin Bagirsakdire Balcicakiri Batikef
The chromite deposits in the ultramafic tectonites of the Dinagat Ophiolite Suite generally occur as massive, irregular-shaped and podiform bodies, as alternating banded masses within a 5 …
comment (deposit): chromite deposits alined in 3 mian ore-bearing zones, which strike n40w. in 1942, lowgrade ore was exposed to a depth of 4 ft. ... comment (development): b. newman leased 2000 acres of the meeker ranch in 1942 in order to clean out old chromite workings and develop low grade ore. references. reference (deposit): logan, c.a ...
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 and the …
the dunite; the ore deposits are parts of the dunite and serpen tine masses in which chromite has been concentrated'by magmatic segregation. These deposits are tabular, strongly banded bod ies, which range in size from stringers to bodies containing more than 50,000 tons, and in grade from a few percent to 50 percent of chromic oxide (CroOj).
The important world-class stratiform deposits include the Bushveld Complex (South Africa), the Great Dyke (Zimbabwe), the Stillwater Complex (United States), and the Kemi deposit (Finland).
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 …
Figures refer to shipping-grade chromite ore, which is deposit quantity and grade normalized to 45% Cr2O3, except for the United States where the grade is normalized to 7% Cr2O3. Citation formats
CHROMITE DEPOSITS IN THE CENTRAL PART OF THE STILLWATER COMPLEX, MONTANA BY A. L. HOWLAND ABSTRACT The chromite deposits of the central part of the Stillwater complex lie in a belt 9 miles long between the valleys of Boulder River and the West Fork of the Stillwater River in Sweet Grass County, Mont. The chromite occurs as layers
Significant producers like Kempersai in the Southern Ural Mountains have large deposits of metallurgical-grade chromite. Podiform deposits, though small, were historically preferred over the vast reserves in stratiform deposits like the Bushveld Complex.
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
This suggests that higher grade chromite deposits in the major podiform chromite subtype tend to be richer in iron and refractory poor. Among the PGE, Rh is positively correlated with Ir and …
of chromite has resulted in such deposits being close to exhaus-tion. The present scenario requires utilization of the indige-nous low-grade chromite for the production of value-added chromium-based chemicals to replace their imports (R & D-PCSIR, 1988). The gravity concentration of low-grade chromite ore is uneco-
In the Koh Safi area, structural discontinuities (mostly faults) trending from the northwest to southeast and east to west are primarily linked to high-grade chromite deposits (Fig. 1a). The slope of the serpentinite units and the chromite lenses within them is also toward the east to northeast, as is the slope of the structural units governing the serpentinites and the …
In contrast, ophiolite-related chromite deposits, although limited and dispersed, contain high-grade ores, leading to their extensive use in industries [2]. Unlike the global predominance of layered intrusion-related chromite deposits, China is dominated by ophiolite-related chromite deposits.
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 …