نتایج جستجو برای: pyrite polymetallic
تعداد نتایج: 4006 فیلتر نتایج به سال:
Pyrite ash (PA) is created by burning pyrite in the chemical production of sulphuric acid. The high concentration of iron oxide, mostly hematite, present in pyrite ash, gives the basis for its application as a source of catalytic iron in a modified Fenton process for anthraquinone dye reactive blue 4 (RB4) degradation. The effect of various operating variables such as catalyst and oxidant conce...
The initial transgressive phase at the Leg 144 Guyots is characterized by a typical association of sedimentary facies (from bottom to top): in situ weathered volcanic rocks; variegated clays, partly pyritic; gray clay, pyritic, homogeneous, or mottled; black clay, peaty, laminated, or bioturbated; and marine argillaceous limestone. Site 877 at Wodejebato Guyot represents the typical development...
The sulfur biogeochemical cycle plays a key role in regulating Earth's surface redox through diverse abiotic and biological reactions that have distinctive stable isotopic fractionations. As such, variations in the sulfur isotopic composition (δ34S) of sedimentary sulfate and sulfide phases over Earth history can be used to infer substantive changes to the Earth's surface environment, including...
in this research, the effect of bubble surface area flux, sb, and particle size on flotation rate constant, k, of pyrite (fes2) particles was studied using bubble-particle interactions. the bubble-particle collision, attachment and detachment efficiencies were calculated under different flow regimes. the k increased with increase in the collision efficiency and decrease in the detachment effici...
To understand the mineralogical association, concentration, and distribution of arsenic (As) in the Hawthorn Group, the chemical and mineralogical composition of 362 samples that were collected from 16 cores in southwestern Florida were examined in detail. In the study area, the Hawthorn Group consisted primarily of a basal carbonate unit (the Arcadia Formation) and an upper siliciclastic unit ...
BACKGROUND There is growing interest in mining polymetallic nodules from the abyssal Clarion-Clipperton Zone (CCZ) in the tropical Pacific Ocean. Despite being the focus of environmental studies for decades, the benthic megafauna of the CCZ remain poorly known. In order to predict and manage the environmental impacts of mining in the CCZ, baseline knowledge of the megafauna is essential. The AB...
This paper presents the first study of Tl isotopes in early diagenetic pyrite. Measurements from two sections deposited during the Toarcian Ocean Anoxic Event (T-OAE, 183 Ma) are compared with data from Late Neogene (<10 Ma) pyrite samples from ODP legs 165 and 167 that were deposited in relatively oxic marine environments. The Tl isotope compositions of Late Neogene pyrites are all significant...
The NE Hungarian Darnó Hill is geologically complex; it is composed of an accretionary mélange complex, which contains Permian, Triassic and Jurassic sedimentary and magmatic blocks. The succession can easily be correlated with the NW Dinarides, using evidences of the different evolutionary stages of the Neotethyan Ocean (rifting, marginal basin opening, closure). Several ore indications are kn...
[1] A marine Permian-Triassic boundary (PTB) section at Nhi Tao, Vietnam, contains a series of at least 9 pyritic horizons characterized by concurrent decreases in pyrite S(dSpy) and carbonate C-isotopic compositions (dCcarb). The first and largest of the events that precipitated these pyritic horizons was coincident with the Late Permian mass extinction, while subsequent events were generally ...
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