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Photomicrograph made with a scanning electron microscope and back-scatter detector: cross section of fly ash particles. Fly ash, flue ash, coal ash, or pulverised fuel ash (in the UK)—plurale tantum: coal combustion residuals (CCRs)—is a coal combustion product that is composed of the particulates that are driven out of coal-fired boilers together with the flue gases.
The Marsh test treats the sample with sulfuric acid and arsenic-free zinc. Even if there are minute amounts of arsenic present, the zinc reduces the trivalent arsenic (As 3+). Here are the two half-reactions: Oxidation: Zn → Zn 2+ + 2 e − Reduction: As 2 O 3 + 12 e − + 6 H + → 2 As 3− + 3 H 2 O. Overall, we have this reaction:
AsH 3 is used in the synthesis of semiconducting materials related to microelectronics and solid-state lasers. Related to phosphorus, arsenic is an n-dopant for silicon and germanium. [8] More importantly, AsH 3 is used to make the semiconductor GaAs by chemical vapor deposition (CVD) at 700–900 °C: Ga(CH 3) 3 + AsH 3 → GaAs + 3 CH 4
Arsinides react with water to yield arsine AsH 3: KAsH 2 + H 2 O → KOH + AsH 3 [ 6 ] Potassium dihydrogen arsinide KAsH 2 reacts with halobenzenes C 6 H 5 X , where X = Cl, Br, I ( chlorobenzene C 6 H 5 Cl , bromobenzene C 6 H 5 Br , iodobenzene C 6 H 5 I ) to produce benzene C 6 H 6 , tetraphenyldiarsine (C 6 H 5 ) 2 As−As(C 6 H 5 ) 2 and ...
One idea is to react carbon dioxide, produced perhaps by the combustion of coal, to form solid carbonates (such as sodium bicarbonate) that could be permanently stored, thus avoiding carbon dioxide emission into the atmosphere. [20] [21] The Solvay process could be modified to give the overall reaction: 2 NaCl + CaCO 3 + CO 2 + H 2 O → 2NaHCO ...
Realgar – arsenic disulfide, an ore of arsenic. Regulus of antimony; Resin of copper – copper(I) chloride (cuprous chloride), formed by heating copper with corrosive sublimate. Rouge/crocus/colcothar – ferric oxide, formed by burning green vitriol in air. Stibnite – antimony or antimony trisulfide, ore of antimony.
The combustion of coal releases diverse chemicals into the air. The main products are water and carbon dioxide, just like the combustion of petroleum. Also released are sulfur dioxide and nitrogen oxides, as well as some mercury. The residue remaining after combustion, coal ash often contains arsenic, mercury
A crucible and tongs, on a green mat. The ash content of a sample is a measure of the amount of inorganic noncombustible material it contains. The residues after a sample is completely burnt - in contrast to the ash remaining after incomplete combustion - typically consist of oxides of the inorganic elements present in the original sample.