Sulfur elemental volcanic

Elucidation of the origin of sulfur in volcanic systems is complicated by the fact that next to SO2, significant amounts of H2S, sulfate and elemental sulfur can also be present. The bulk sulfur isotope composition must be calculated using mass balance constraints. The principal sulfur gas in equilibrium with basaltic melts at low pressure and high temperature is SO2. With decreasing temperature and/or increasing... 

Early humans doubtless found elemental sulfur in volcanic craters, encrusting the edges of hot sulfur springs, and embedded in limestone formations. They discovered that it would bum and used it for medicinal purposes, as a bleach, as a fumigant, as a colorant, and as incense. Its use for these purposes is mentioned in ancient writings. The Romans produced incendiary weapons from sulfur. In the thirteenth century, the Chinese invented gunpowder using sulfur, nitrate, and charcoal. 

Sulfur consumption by region in 1992-94 is shown in Table 5.24. For the short to medium term, sulfur is expected to remain in surplus due to increased byproduct sulfur production. Increasing demand for natural gas and the increased need for pollution control will lead to increasing production of recovered sulfur. Elemental sulfur from evaporites and volcanic rocks will be available for many years. The fertilizer industry should be able to obtain the sulfur it needs over the next decade, but the lowest cost reserves presently being used have a limited life expectancy. 

World sulfur production in 1989 was 40 million tons. " Over 99 percent of the sulfur that is marketed is sold as crude sulfur. The two primary grades are bright, which is bright yellow and at least 99.5 percent (typically 99.9-h %) pure, and dark, which can contain upwards of 0.25 percent carbonaceous material. Recovered sulfur generally is bright, whereas mined sulfur often is dark owing to traces of crude oil, which is associated with salt-dome sulfur deposits. Volcanic sulfur deposits yield bright sulfur, but it often is contaminated with toxic metal oxides. Sulfuric acid production accounts for 93 percent of the elemental sulfur... 

Sulfur constitutes about 0.052 wt % of the earth s cmst. The forms in which it is ordinarily found include elemental or native sulfur in unconsohdated volcanic rocks, in anhydrite over salt-dome stmctures, and in bedded anhydrite or gypsum evaporate basin formations combined sulfur in metal sulfide ores and mineral sulfates hydrogen sulfide in natural gas organic sulfur compounds in petroleum and tar sands and a combination of both pyritic and organic sulfur compounds in coal (qv). 

Sulfur for commercial purposes is derived mainly from native elemental sulfur mined by the Frasch process. Large quantities of sulfur are also recovered from the roasting of metal sulfides and the refining of crude oil, i.e., from the sulfur by-products of purified sour natural gas and petroleum (the designation sour is generally associated with high-sulfur petroleum products). Reserves of elemental sulfur in evaporite and volcanic deposits and of sulfur associated with natural gas,... 

Scientists believe that the sulfur in Venus atmosphere came from volcanic eruptions. Earth has experienced its fair share of volcanic eruptions, too. However, the sulfur from early eruptions on Earth was incorporated into solid sulfur compounds. Indeed, sulfur is an important element found in many of the compounds that make up Earths crust. 

A Sulfur occurs as an element in volcanic areas, and the beautiful sulfur crystals are sought after. Technically, sulfur is increasingly isolated from natural oil. 

Acid rain is caused primarily by sulfur dioxide emissions from burning fossil fuels such as coal, oil, and natural gas. Sulfur is an impurity in these fuels for example, coal typically contains 2-3% by weight sulfur.1M Other sources of sulfur include the industrial smelting of metal sulfide ores to produce the elemental metal and, in some parts of the world, volcanic eruptions. When fossils fuels are burned, sulfur is oxidized to sulfur dioxide (SO2) and trace amounts of sulfur trioxide (SC>3)J21 The release of sulfur dioxide and sulfur trioxide emissions to the atmosphere is the major source of acid rain. These gases combine with oxygen and water vapor to form a fine mist of sulfuric acid that settles on land, on vegetation, and in the ocean. 

Elemental sulfur1-4 occurs naturally in association with volcanic vents and, in Texas and Louisiana, as underground deposits. The latter are mined by injecting air and superheated water, which melts the sulfur and carries it to the surface in the return flow (the Frasch process). Most of the sulfur used in industry, however, comes as a by-product of the desulfurization of fossil fuels. For example, Albertan sour natural gas, which often contains over 30% (90%, in some cases) hydrogen sulfide (H2S), as well as hydrocarbons (mainly methane) and small amounts of C02, carbonyl sulfide (COS), and water, is sweetened by scrubbing out the H2S and then converting it to elemental S in the Claus process.5 The Claus process is applicable in any industrial operation that produces H2S (see Section 8.5) it converts this highly toxic gas to nontoxic, relatively unreactive, and easily transportable solid sulfur. 

Sulfur is found in large quantities but in various forms throughout the world. It is found in metal ores such as copper pyrites or chalcopyrite (CuFeS2) and zinc blende (ZnS) and in volcanic regions of the world. Natural gas and oil contain sulfur and its compounds, but the majority of this sulfur is removed as it would cause environmental problems. Sulfur obtained from these sources is known as recovered sulfur and it is an important source of the element. It is also found as elemental sulfur in sulfur beds in Poland, Russia and the US (Louisiana). These sulfur beds are typically 200 m below the ground. Sulfur from these beds is extracted using the Frasch process, named after its inventor Hermann Frasch. 

Sulfur and sulfur compounds and their relationship to volcanic silicate rocks are at the heart of lo s surface chemistry. The satellite s low ultraviolet albedo combined with high visible and near-infrared reflectance suggested elemental sulfur to a number of researchers studying telescopic spectra (Wamsteker, 1973 Wamsteker et al., 1974), although laboratory measurements of pure sulfur differ somewhat from lo s average color. The presence of sulfur ions detected in Jupiter s magnetosphere near lo (Kupo et al., 1976) also pointed toward an lo source of sulfur. 

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