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In the Gutzeit test, AsH 3 is generated by reduction of aqueous arsenic compounds, typically arsenites, with Zn in the presence of H 2 SO 4. The evolved gaseous AsH 3 is then exposed to AgNO 3 either as powder or as a solution. With solid AgNO 3, AsH 3 reacts to produce yellow Ag 4 AsNO 3, whereas AsH 3 reacts with a solution of AgNO 3 to give ...
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.
Arsenic is also a common n-type dopant in semiconductor electronic devices, and a component of the III–V compound semiconductor gallium arsenide. Arsenic and its compounds, especially the trioxide, are used in the production of pesticides, treated wood products, herbicides, and insecticides. These applications are declining with the ...
A coal-fired power plant with ash ponds. Coal ash, also known as coal combustion residuals (CCRs), is the mineral residue that remains from burning coal. Exposure to coal ash and to the toxic substances it contains may pose a health risk to workers in coal-fired power plants and residents living near coal ash disposal sites.
In industrial chemistry, coal gasification is the process of producing syngas—a mixture consisting primarily of carbon monoxide (CO), hydrogen (H 2), carbon dioxide (CO 2), methane (CH 4), and water vapour (H 2 O)—from coal and water, air and/or oxygen. Historically, coal was gasified to produce coal gas, also known as "town gas
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 ...
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
Many materials can sustain a smouldering reaction, including coal, tobacco, decaying wood and sawdust, biomass fuels on the forest surface and subsurface , cotton clothing and string, and polymeric foams (e.g., upholstery and bedding materials). Smouldering fuels are generally porous, permeable to flow and formed by aggregates (particulates ...