Calcium, sulfides

Oldhamite, see Calcium sulfide Opal, see Silicon dioxide Orpiment, see Arsenic trisulfide Oxygen powder, see Sodium peroxide... 

Historically, soda ash was produced by extracting the ashes of certain plants, such as Spanish barilla, and evaporating the resultant Hquor. The first large scale, commercial synthetic plant employed the LeBlanc (Nicolas LeBlanc (1742—1806)) process (5). In this process, salt (NaCl) reacts with sulfuric acid to produce sodium sulfate and hydrochloric acid. The sodium sulfate is then roasted with limestone and coal and the resulting sodium carbonate—calcium sulfide mixture (black ash) is leached with water to extract the sodium carbonate. The LeBlanc process was last used in 1916—1917 it was expensive and caused significant pollution. 

The calcium oxide product is supplemented with fresh limestone and returned to the fluidized bed. Two undesirable side reactions can occur in the regeneration of spent lime leading to the production of calcium sulfide ... 

Mercury spills should be cleaned up immediately by use of a special vacuum cleaner. The area should then be washed with a dilute calcium sulfide solution. Small quantities of mercury can be picked up by mixing with copper metal granules or powder, or with zinc granules or powder. To avoid or minimize spills, some plants use steel trays as pallets so that a spih, whether of mercury or a mercury compound, is contained on the steel tray. 

Manufacture. Small cylinders of hydrogen sulfide are readily available for laboratory purposes, but the gas can also be easily synthesized by action of dilute sulfuric or hydrochloric acid on iron sulfide, calcium sulfide [20548-54-3], zinc sulfide [1314-98-3], or sodium hydrosulfide [16721 -80-5]. The reaction usually is mn in a Kipp generator, which regulates the addition of the acid to maintain a steady hydrogen sulfide pressure. Small laboratory quantities of hydrogen sulfide can be easily formed by heating at 280—320°C a mixture of sulfur and a hydrogen-rich, nonvolatile aUphatic substance, eg, paraffin. Gas evolution proceeds more smoothly if asbestos or diatomaceous earth is also present. 

Phases Formed in Pordand Cements. Most clinker compounds take up small amounts of other components to form soHd solutions (11). Best known of these phases is the C S soHd solution called aHte. Phases that may occur Hi Portiand cement clinker are given Hi Table 1. In addition, a variety of minor phases may occur Hi Portiand cement clinker when certain minor elements are present Hi quantities above that which can be dissolved Hi other phases. Under reducHig conditions Hi the kiln, reduced phases, such as ferrous oxide [1345-25-17, FeO, and calcium sulfide [20548-54-3] CaS, maybe formed. 

The manner in which many of these bacteria cany on their chemical processes is qmte comphcated and in some cases not fuUy understood. The role of sulfate-reducing bacteria (anaerobic) in promoting corrosion has been extensively investigated. The sulfates in shghtly acid to alkaline (pH 6 to 9) soils are reduced by these bacteria to form calcium sulfide and hydrogen sulfide. When these compounds come in contact with underground iron pipes, conversion of the iron to iron sulfide occurs. As these bacieria thrive under these conditions, they will continue to promote this reaction until failure of the pipe occurs. 

Because calcium sulfide contained in the black ash had a highly unpleasant odor, methods were developed to remove the odor by recovering the sulfur, therein providing at least part of the raw-material for the sulfuric acid required in the first part of the process. Thus, the Leblanc prtKcss demonstrated, at the very beginning, the typical ability of the chemical industry to develop new processes and new products, and often in so doing to turn a liability into an asset. 

Schwefel-indium, n. indium sulfide. -jodUr, n. sulfur monoiodide, -kadmium, n. cadmium sulfide. -kalium,n. potassium sulfide, -kalk, m. lime-sulfur, -kalkbrtihe, /. lime-sulfur mixture (for spraying), -kalzium, n. calcium sulfide, -kammer, /. sulfur chamber, sulfuring room, sulfur stove, -karbolsaure, /. sulfo carbolic acid, -kastenbleiche, /. (Dyeing) stoving. 

Self-Test 5.6B Predict the likely structure of solid calcium sulfide. 

Beryllium sulfide, BeS beryllium selenide, BeSe beryllium telluride, BeTe beryllium polonide, BePo magnesium sulfide, MgS magnesium selenide, MgSe magnesium telluride, MgTe calcium sulfide, CaS (oldhamite) calcium selenide, CaSe calcium telluride, CaTe strontium sulfide, SrS strontium selenide, SrSe barium sulfide, BaS barium selenide, BaSe barium hydrosulfide, Ba(HS)2 barium hydrosulfide tetrahydrate, Ba(HS)2 H20. 

In the blast furnace, the reaction of the nitrogen in the blast with coke leads to the formation of poisonous chemicals such as hydrogen cyanide and cyanogens, and each cubic meter of the blast furnace gas contains from 200 to 2000 mg of these compounds. The blast furnace gas is scrubbed with water in the dust collection system the cyanide compounds dissolve in the water, which is then discharged after the compounds have been destroyed. Another poisonous emission in blast furnace operations is hydrogen sulfide. The sulfur present in the coke is converted into calcium sulfide in the slag, the water-quenching of... 

SODIUM SULFATE LIMESTONE CHARCOAL SODIUM CARBONATE CALCIUM SULFIDE CARBON DIOXIDE... 

Breath Collect air from breathing zone using a midget impinger containing calcium hydroxide-calcium sulfide-arabinogalactan slurry add solution of A/iV-dimethyl-p-phenylenedi-amine and ferric chloride. Spectrophotometry 0.20 pg/m3 80 NIOSH 1977... 

Mixtures of potassium nitrate with antimony trisulfide [1], barium sulfide, calcium sulfide, germanium monosulfide or titanium disulfide all explode on heating [2]. The mixture with arsenic disulfide is detonable, and addition of sulfur gives a pyrotechnic composition [2], Mixtures with molybdenum disulfide are also detonable [3], Interaction with sulfides in molten mixtures is violent [4],... 

Calcium sulfide, strontium sulfide or barium sulfide react vigorously with lead dioxide on heating. 

The heat integration of this configuration includes the utilization of the heat generated from the combustion of calcium sulfide in the first chemical loop in the regeneration of the calcium-based sorbent in the second chemical loop (Andrus et al., 2005). The output gas... 

Chance Also called Chance-Claus. A process for recovering sulfur from the calcium sulfide residues from the Leblanc process. Treatment of a suspension of the residues with carbon dioxide generates hydrogen sulfide, which is converted to sulfur dioxide by the Claus proces. The sulfur dioxide is converted to sulfuric acid. Developed by A. M. and J. F. Chance 1882 to 1887 and widely used until the Leblanc process was superseded by the Solvay process. 

The black product was extracted with water and the sodium carbonate in it was recovered by concentration and crystallization. The residue, chiefly calcium sulfide, known as galigu, was dumped on land and created an environmental nuisance for many years because it never hardened. The process was invented by N. Leblanc in France in 1789, in response to a competition organized by the French Academy of Sciences. Operation of the first factory was delayed for several years because of the French Revolution. The process was operated widely until it was progressively superseded by the Ammonia-soda process in 1872. But it was still in use in Bolton, UK, until 1938, and the last plant in Europe closed in 1992. See also Black ash. 

E. Becquerel Emission of light by calcium sulfide upon excitation in the UV. First statement that the emitted light is of longer wavelength than the incident light... 

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