نتایج جستجو برای: pyrite polymetallic

تعداد نتایج: 4006  

2010
Corey A Cohn Shawn C Fisher Bruce J Brownawell Martin AA Schoonen

Cellular exposure to particulate matter with concomitant formation of reactive oxygen species (ROS) and oxidization of biomolecules may lead to negative health outcomes. Evaluating the particle-induced formation of ROS and the oxidation products from reaction of ROS with biomolecules is useful for gaining a mechanistic understanding of particle-induced oxidative stress. Aqueous suspensions of p...

2011
Huayong Chen T. Kurtis Kyser Alan H. Clark

TheMarcona–Mina Justa deposit cluster, hosted by Lower Paleozoic metaclastic rocks and Middle Jurassic shallow marine andesites, incorporates the most important known magnetite mineralization in the Andes at Marcona (1.9 Gt at 55.4% Fe and 0.12% Cu) and one of the few major iron oxide–copper–gold (IOCG) deposits with economic Cu grades (346.6 Mt at 0.71% Cu, 3.8 g/t Ag and 0.03 g/t Au) at Mina ...

Journal: :Geochemical Transactions 2007
Stefan Hunger Liane G Benning

The formation of pyrite (FeS2) from iron monosulfide precursors in anoxic sediments has been suggested to proceed via mackinawite (FeS) and greigite (Fe3S4). Despite decades of research, the mechanisms of pyrite formation are not sufficiently understood because solid and dissolved intermediates are oxygen-sensitive and poorly crystalline and therefore notoriously difficult to characterize and q...

Journal: :Ore Geology Reviews 2023

With >90 known deposits containing original reserves of >2400 Mt sulfide ore, the Iberian Pyrite Belt (IPB) is largest volcanogenic massive (VMS) province on Earth. In these evolving mineral systems, texturally different pyrite exhibits characteristic mineralogy and trace element fingerprints. (Py-1), which well preserved in polymetallic ores that crystallized at earliest stage VMS deposit form...

Journal: :Biochemical Society transactions 2012
Julian Bosch Rainer U Meckenstock

Pyrite (FeS2) is a major iron- and sulfur-containing mineral phase in the environment. Oxidation of pyrite by aerobic micro-organisms has been well investigated. However, the reactivity of pyrite under anoxic conditions is still an open question. In the present paper, we summarize field and laboratory data on this chemolithotrophic respiration process with nitrate as terminal electron acceptor....

2013
Ruoshi Sun Gerbrand Ceder R. P. Simmons

Despite its exceptional optical absorptivity, suitable band gap, and earth abundance, the low open-circuit voltage of pyrite FeS2 has remained the biggest challenge preventing its use in photovoltaic devices. Two widely-accepted causes are: (i) Fermi level pinning caused by intrinsic surface states that appear as gap states; (ii) presence of the polymorph marcasite. Based on density-functional ...

2013
A. K. Vardanyan

Leptospirillum sp. str. ZC isolated from bioleaching pulp of zinc concentrate is capable of oxidizing Fe (II) with the optimal temperature of 37oC. In pure culture bacteria is unable to oxidize pyrite, however, its growth together with sulfur oxidizing A.albertensis str.SO-2 significantly enhances the efficiency of pyrite bioleaching. The correlation between pyrite biooxidation and adhesion of ...

2016
Liangqian Fan Xi Zhou Hongbing Luo Jie Deng Li Dai Zhengfu Ju Zhiming Zhu Likou Zou Lin Ji Bei Li Lin Cheng Marc A. Rosen

To provide the basic information about the release of heavy metals from the pyrite tailings of Huangjiagou pyrite mine, the pyrite tailings were investigated through a series of batch experiments under different initial pH of extractant, temperature, liquid-solid (LS) ratio, and soaking time conditions. Moreover, calcium carbonate was added in the pyrite tailings to determine the reduction effe...

Journal: :Geochemical Transactions 2003
Xiang Zhang Michael J Borda Martin AA Schoonen Daniel R Strongin

The effect of a diacetylene-containing phospholipid on the oxidation of pyrite, FeS2, was investigated. Earlier work reported by our research group showed that the adsorption of 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3phosphocholine on pyrite suppressed the extent of its oxidation by about 75% over a specific time period. Results presented here show that the pre-exposure to UV radiation of th...

2011
Paula Lindgren John Parnell Nils G Holm Curt Broman

One of the key-principles of the iron-sulphur world theory is to bring organic molecules close enough to interact with each other, using the surface of pyrite as a substrate in a hydrothermal setting. The present paper explores the relationship of pyrite and organic matter in a hydrothermal setting from the geological record; in hydrothermal calcite veins from Carboniferous limestones in centra...

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