A new indicator mineral methodology based on a generic Bi …
Porphyry-epithermal and orogenic gold are two of the most important styles of gold-bearing mineralization within orogenic belts. Populations of detrital gold resulting from bulk erosion of such regions may exhibit a compositional continuum wherein Ag, Cu, and Hg in the gold alloy may vary across the full range exhibited by natural gold. This …
Major Mines & Projects | Boddington Mine
The earliest phase consists of widespread silica–biotite alteration and complex quartz + albite + molybdenite ± muscovite ± clinozoisite ± chalcopyrite veins, all of which are variably deformed by ductile shear zones. ... Gold in the laterite zones occurs in association with iron and aluminum hydroxides. Gold in the saprolite is hosted in ...
Molybdenite Saturation in Silicic Magmas: Occurrence and …
Molybdenite (60 wt % Mo) contains about 100 000 times more Mo than the coexisting melt. Once molybdenite saturation has been attained the Mo concentration of the melt is capped and cannot increase unless conditions of higher MoS 2 solubility are …
Zircon U-Pb and molybdenite Re-Os dating for the Beiya gold
Therefore, the molybdenite Re-Os isochron ages (38.1-34.7 Ma) may not correspond to the gold deposition although the molybdenite results have been widely regarded as the best ages for the Beiya ...
Zircon U–Pb–Hf–O and molybdenite Re–Os isotopic
The porphyry gold-only deposit represents a relatively new type of economic gold ore devoid of economically mineable copper and molybdenum and is commonly formed in subduction-related volcano-plutonic arcs (Sillitoe, 1979, Sillitoe, 2010).So far, only tens of porphyry gold deposit have been found and reported worldwide (Fig. 1), e.g., the …
Absolute timing of sulfide and gold mineralization: A
An Re-Os age of 92.6 ± 0.9 Ma from molybdenite intergrown with gold in the Fort Knox ore (Selby et al., 2002) is similar to the U-Pb zircon age (in Bakke, 1995) of 92.5 ± 0.2 Ma for the ...
Molybdenite: Mineral properties, uses, geologic occurrence
Molybdenite is a rare mineral composed of molybdenum and sulfur, with a chemical composition of MoS 2. It occurs in igneous and metamorphic rocks as gray hexagonal crystals and foliated masses with a metallic luster. Molybdenite is the most important ore of molybdenum and often contains minor amounts of rhenium which are often produced as …
Effects of sulphide minerals and dissolved oxygen on the …
The relative rates of gold and silver dissolution in the presence of the sulphide mir~erals are summarized below. Minerals that produce dissolution rates …
Molybdenite
Molybdenite was previously known as molybdena and molybdena was confused with and ... alumina, boron nitride, carbon nanotubes, graphene; (3) surface property modifiers such as silica, molybdenite, graphite, boron nitride; (4) fire retardants, for example, metal hydroxides; and (5) processing aids and stabilizers such as fumed silica and ...
Mineral Resources – Department of Mining and Geology
In view of the gap in technology for mining of gold placers in the country, a program for exploration and pilot scale mining was taken up during 1994-'96 through French Assistance (BRGM). The studies confirmed the incidence of gold on the present day river channel with an average grade of 0.1 g/m3.
Structural and hydrothermal alteration mapping related to orogenic gold
The Gurara area (Fig. 1), situated in the Kushaka schist belt of north-central Nigeria, has been reported to be associated with gold mineralization in stream sediments (alluvial), soil sediments (eluvial), and within geologic structures and quartz veins [].Although approximately 90% of Nigeria's total gold production is from alluvial and …
Ore Genesis and Hydrothermal Evolution of the
Molybdenite samples from stages II and III record a narrow range of δ 34 S values between 3.3 and 5.0‰, whereas pyrite samples from stages I to IV show decreasing δ 34 S values between 2.1 and 5.0‰. Molybdenite also has 206 Pb/ 204 Pb, 207 Pb/ 204 Pb, and 208 Pb/ 204 Pb ratios similar to those of granitic
Selective flotation of chalcopyrite and molybdenite with H
The floatability of untreated chalcopyrite and molybdenite was ∼85% and ∼73%, respectively, and decreased with increasing the ozone oxidation treatment time (Fig. 1 A).A sudden drop in the floatability of both minerals was observed within 2 min of the ozone oxidation treatment.After the ozone oxidation treatment, the floatability of …
gold and molybdenite in silica
The silica coating increases the photothermal stability of gold nanorods, thus helping retain their superior optical properties under high continuous and pulsed laser fluencies. 1,3,6 Silica-coated gold nanorods have also been shown to significantly increase cellular uptake over PEG-coated gold nanorods, which in turn translates into a better ...
Absolute timing of sulfide and gold mineralization: A …
New Re-Os molybdenite dates from two lode gold deposits of the Tintina Gold Belt, Alaska, provide direct timing constraints for sulfide and gold mineralization. At Fort Knox, the Re-Os molybdenite date is identical to the U-Pb zircon age for the host intrusion, supporting an intrusive-related origin for the deposit. ...
Extremely Re-Rich Molybdenite from Porphyry Cu-Mo-Au …
Magmatic vapors resulted in the formation of high-sulfidation Cu–Au–Te mineralization within advanced argillic alteration lithocaps and fluid inclusion evidence suggests that rheniite, Re-rich molybdenite, chalcopyrite and native gold at Pagoni Rachi and Konos prospects may have precipitated as temperatures fell below 400 °C during phase ...
Molybdenite Saturation in Silicic Magmas: Occurrence and …
Corpus ID: 129398030. Molybdenite Saturation in Silicic Magmas: Occurrence and Petrological Implications. A. Audétat, D. Dolejš, J. Lowenstern. …
Scroll-like and platy molybdenite-3R from the Ufaley …
Scroll-like crystals of molybdenite, 2–5 mm in size, were found in phengite rock from the outer contact of the granular quartz vein of the Kyshtym quartz deposit. Platy and partly scrolled molybdenite occur in the same phengite rock from the outer contact of the quartz–feldspar pegmatite of the Slyudyanogorsk mica deposit.
Recent progress on research of molybdenite flotation: A …
In this manuscript, recent progress on molybdenite flotation and the corresponding mechanisms are discussed. 2. Commercial production and process flowsheets for molybdenite flotation. The output of molybdenum concentrates from mines all over the world is 297,000 ton in 2017, as shown in Table 1 [ 20 ].
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Gaseous transport and deposition of gold in magmatic fluid …
Abstract. The distribution of gold in high-temperature fumarole gases of the Kudryavy volcano (Kurile Islands) was measured for gas, gas condensate, natural …
Molybdenite saturation in silicic magmas: Occurrence and …
January 1, 2011. We identified molybdenite (MoS 2) as an accessory magmatic phase in 13 out of 27 felsic magma systems examined worldwide. The molybdenite occurs as small …
Recent progress on research of molybdenite flotation: A review
Commercial production and process flowsheets for molybdenite flotation are reviewed. Mineralogy, microstructure, and surface properties of molybdenite are …
A novel copper depressant for selective flotation of chalcopyrite …
Chalcopyrite (CuFeS 2) and molybdenite (MoS 2) as typical sulfide minerals are very easy for co-flotation in practice, but their mutual separation consumes a large quantity of flotation reagents, particularly for superfinely associated chalcopyrite and molybdenite as encountered in most porphyry copper deposits.Pulsating high gradient …
9.2.2: Sulfides and Sulfosalts
The most common gold and goldish sulfides are pyrite, chalcopyrite, and pyrrhotite (shown in Figures below). They can be very hard to tell apart. ... The photos below show examples of galena (Figure 9.34), molybdenite (Figure 9.35), and stibnite (Figure 9.36). The lusters of the samples in these photos are not particularly metallic, but …
Purification of an Indigenous Molybdenite for Enhanced …
In this study, molybdenum-cum-silica compound preparation from indigenous molybdenite was examined via oxidative roasting and chemical leaching. The influence of pertinent parameters such as leachant concentration, reaction temperature, and particle size on the extent of molybdenite ore reacted was thoroughly investigated.
Dissecting the Re-Os molybdenite geochronometer
However, molybdenite (MoS 2) the most common molybdenum ore mineral constitutes a particular case within sulphide minerals because it contains high Re (in the ppm range) and 187 Os (at ppb levels ...
Gaseous transport and deposition of gold in magmatic fluid …
The distribution of gold in high-temperature fumarole gases of the Kudryavy volcano (Kurile Islands) was measured for gas, gas condensate, natural fumarolic sublimates, and precipitates in silica tubes from vents with outlet temperatures ranging from 380 to 870°C. Gold abundance in condensates ranges from 0.3 to 2.4 ppb, which is …
Evidence for a genetic link between gold-silver telluride and …
Abstract. The Golden Sunlight gold-silver telluride deposit, hosted primarily within the Mineral Hill breccia pipe, is spatially related to a high-level, Late Cretaceous …