Calcium silicon

Calcium silicon (CaSi2) is produced by reacting lime, quartz and coal at above 1200 °C in an electric arc furnace. The raw materials are heated to the required temperature and the carbon reduces the lime and silica (31.11) [31.10], 

Calcium silicon is used in the iron and steel industry as a de-oxidizer and desul-furizer and for the modification of non-metallic inclusions. A high calcium quicklime is required (e.g. 94 to 97 % CaO) with controlled levels of combined CO2 and water. 

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Calcium—Silicon. Calcium—silicon and calcium—barium—siUcon are made in the submerged-arc electric furnace by carbon reduction of lime, sihca rock, and barites. Commercial calcium—silicon contains 28—32% calcium, 60—65% siUcon, and 3% iron (max). Barium-bearing alloys contains 16—20% calcium, 9—12% barium, and 53—59% sihcon. Calcium can also be added as an ahoy containing 10—13% calcium, 14—18% barium, 19—21% aluminum, and 38—40% shicon These ahoys are used to deoxidize and degasify steel. They produce complex calcium shicate inclusions that are minimally harm fill to physical properties and prevent the formation of alumina-type inclusions, a principal source of fatigue failure in highly stressed ahoy steels. As a sulfide former, they promote random distribution of sulfides, thereby minimizing chain-type inclusions. In cast iron, they are used as an inoculant. 

White smoke compositions based on hexachloroethane with zinc, zinc oxide and <5% aluminium or <10% calcium silicon... 

In a study of dental silicate cements, Kent, Fletcher Wilson (1970) used electron probe analysis to study the fully set material. Their method of sample preparation varied slightly from the general one described above, in that they embedded their set cement in epoxy resin, polished the surface to flatness, and then coated it with a 2-nm carbon layer to provide electrical conductivity. They analysed the various areas of the cement for calcium, silicon, aluminium and phosphorus, and found that the cement comprised a matrix containing phosphorus, aluminium and calcium, but not silicon. The aluminosilicate glass was assumed to develop into a gel which was relatively depleted in calcium. 

The finely powdered silicide is a significant dust explosion hazard [1]. The lower explosion limit for a calcium-silicon dust cloud of mean particle size 9.7 pm was measured as 79 g/m3, in good agreement with a calculated value [2], Other dust cloud parameters are presented and related to predictions [3],... 

Combustion of Calcium-Silicon in a Mixture with Lead Nitrate (tide only translated)... 

Calcium-silicon alloy, 22 519 Calcium-silver technology, for batteries, 22 684... 

In steelmaking applications, calcium disilicide has hitherto been generally more widely used than calcium metal. Total consumption of calcium disilicide in the steel industry worldwide is estimated to be about 6000 tons (30% Ca). Principal producers are Pechiney Electrometallurgie of France and SKW Trostberg of Germany. In the United States, the Norwegian company Elkem Metal produces up to 2500 metric tons of calcium disilicide. Also produced are CalSiBar, a calcium—silicon—barium alloy, and Hypercal, a calcium—silicon—barium—aluminum ferroalloy. 

In order to substantiate further the mineral matter content information received from the x-ray diffraction analyses, several coke pellets were scanned for sulfur, iron, calcium, silicon, aluminum and potassium in the electron microprobe. Electron probe results showed abundant silicon, suggesting quartz (Si02), considerable aluminum, suggesting kaolinite [Ali>Sii Oii(OH)4] and, relatively speaking, little iron, sulfur, calcium, or potassium. 

For certain metal alloys, a calcium silicon alloy is required. This alloy also is used as a steel deoxidizer and is favored because it forms a low-melting-point calcium silicate product A representative composition of the alloy is 30-33% Ca, 60-64% Si, 3-5% Fe, 1-2% Al, 0.3-0.6% C, and less than 0.15% S and P. 

Kenneth and Steve Shoulders report an experiment in which a previously deuteron-loaded palladium cathode was subjected to the impact of a charge cluster [22]. Where the charge cluster impacted the deuteron-loaded palladium a visually-evident, explosive-like reaction occurs (Fig. 8). The palladium cathode was then subjected to an X-ray analysis of the impact crater (see chart in Fig. 8). Typically, the X-ray analysis shows a considerable number of elements not seen when scanning the nearby palladium surface. Such elements as oxygen, calcium, silicon, and magnesium are detected in the exploded region where a charge cluster impacted the palladium. 

In order to prevent the decomposition of the higher chlorides of silicon, it is very important that only a small part of the reaction tube should be heated at a time. When the chlorine is first passed through the reaction tube, the temperature of the heating coil is about 250°C. when the reaction is well started, it is lowered to about 150°C. The best rate of flow of chlorine is less than two bubbles per second. Under these conditions, in about 12 or 14 days, all the calcium-silicon will be used up, and about 700 ml. of liquid silicon chlorides will be collected. 

The calcium-silicon used was 30 to 35 per cent calcium and was supplied by the Electro-Metallurgical Sales Corporation, Niagara Falls, N. Y. 

The finely powdered silicide is a significant dust explosion hazard [1]. The lower explosion limit for a calcium—silicon dust cloud of mean particle size 9.7 pm was... 

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