pyrites


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pyrites

1. another name for pyrite
2. any of a number of other disulphides of metals, esp of copper and tin

Pyrites

 

pyrite ores consisting predominantly of sulfurous (sulfide) ore minerals. The composition of pyrites is dominated by iron sulfides (pyrite, pyrrhotite, marcasite). Also present are the sulfides of copper (chalcopyrite, bornite), zinc (sphalerite), and lead (galenite) and barium sulfate (barite). Pyrite deposits consist of massive as well as disseminated ores. These deposits have the shape of beds, lenses, stocks, and veins measuring up to 5,000 m long and 250 m thick; they occur at depths of as much as 2,000 m.

In terms of formation and occurrence, pyrites are closely linked to the basic and alkaline igneous rocks that issued onto the floor of ancient seas and formed extended ophiolite zones characteristic of the early stage of geosynclinal development. In the volcanic zones, pyrites form discontinuous chains measuring up to several thousand kilometers long. Pyrites arise in the late stage of volcanic cycles, when the eruption of the primary magma has been replaced by alkaline and acidic lavas, which are accompanied by the heavy venting of volcanic gaseous and liquid solutions. The solutions carry a large amount of metals that combine with the sulfurous sublimates and are deposited in the form of sulfides, creating the pyrites. That portion of the pyrites that arises along the seepage paths of the solutions through the volcanic rock forms hydrothermal metasomatic deposits. The other part of the mineral matter carried by the volcanic solutions reaches the floor of the sea and, in being deposited here, creates the volcanogenic sedimentary deposits of pyrites.

The accumulation of pyrites occurs over a long period of time, and in the early stages, predominantly the sulfurous iron compounds form, which are of limited practical interest. The pyrite deposits of copper, zinc, and lead arise in the later stages.

In the USSR the following pyrite deposits are known: Proterozoic (Karelia), Lower Paleozoic (Buriatia and Tuva), Middle and Upper Paleozoic (Urals and Caucasus), and Mesozoic and Cenozoic (Caucasus) deposits. Abroad, there are Proterozoic (Canada), Lower Paleozoic (Norway and Australia), Middle and Upper Paleozoic (Spain, Portugal), Mesozoic (Yugoslavia), and Cenozoic (Japan, Turkey, Greece, Cuba) deposits.

Pyrite deposits are an important source for obtaining copper, zinc, and lead and, in part, gold, silver, bismuth, cadmium, indium, barium, selenium, sulfur, and sulfuric acid.

REFERENCE

Genezis endogennykh rudnykh mestorozhdenii. Moscow, 1968.

V. I. SMIRNOV

References in periodicals archive ?
The effect of pyrite catalyst on the hydroliquefaction of Goynuk (Turkey) oil shale in the presence of toluene // Fuel.
The presence of these minerals distinguishes the rocks of the Braen quarry from those in the trap rock quarries within the Orange Mountain Basalt, where pyrite and zinc sulfides are either rare or absent.
The convenient hydrochloric/hydrofluoric acid treatment is effective in removing carbonate, oxide and monosulfide minerals from sedimentary rocks, and during this treatment kerogen and pyrite remain almost fully unaffected [12, 13].
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It can be caused by dissolution of pyrites in the oxygen-abundant water in spring.
These phrases have 6-letter tautonymic envelopes: ANTISEPTIC LUBRICANT, BELLY WINBEL CERVICAL CANCER (bt), DESIGNATED TRADES (coined), EASTERN SEAS (coined), FEROCIOUS HEIFER (coined), GARLIC VINEGAR, HERB CHRISTOPHER, INDEPENDENT MIND (bt), KERSEY MAKER, LORD CHANCELLOR, MANCHESTER WAREHOUSEMAN, NESTING CRANES (coined), OVEN GLOVE, PERSONAL SHOPPER, PHYSICAL GEOGRAPHY, REMAINDER THEOREM, REST CURES, SAMARITAN'S BALSAM, TESSELLATED PYRITES, UNDER GROUND, VERT OVER, WAGES' SWAG (coined)
At the same time, there are advanced plans to extract cobalt from the pyrites stockpile.
Contract notice: Reconstruction of streets cobalt pyrites, morning glories, budziszynskiej and familijna in lodz.
He finally got so many pyrite specimens, and I mean fine ones, that he told Terry to stop sending pyrites.
It can be caused by dissolution of pyrites in oxygen-abundant water in spring, but the influence of agricultural pollution cannot be excluded either.
The Nampundwe pyrites are used as fuel for a cobalt concentrate roaster, which in turn produces sulphuric acid for copper leach processes.
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