Arsenic nonferrous metal production

The major sources of airborne anthropogenic arsenic are smelting of metals (mainly nonferrous metal production), burning of fossil fuels, and steel and cement production. The main natural emissions (possibly somewhat underestimated) are terrestrial volcanic exhalations and eruptions and submarine volcanism (Chilvers and Peterson 1987). Most trace metals are emitted on fine particles and thus can be... 

Weathering results in the release of arsenic in soluble forms and it is estimated (3) that 45 X 106 kg/year enter the ocean. Atmospheric contributions comprise very roughly 18 x 108 kg/year from volcanic activity, and 26 x 106 Kg/year from soils and sediments as volatile arsines (4). Human activities result in introduction of (a) up to 26 X 106 kg/year to the atmosphere (5), mainly from nonferrous metal production (b) about 100 X 106 kg/year to land from mine tailings, smelter slags and water, coal fly ash and bottom ash, and commercial product wastage, etc., and (c) about 40 x 106 kg/year into aquatic systems from domestic waste water, electric generating plants, and ferrous smelters, etc, (6). 

Current uses of arsenic are in pesticides, cotton desiccants, and wood preservatives. Arsenic is also used as a bronzing and decolorizing agent in the manufacture of glass, and in the production of semiconductors (Tanaka, 2004), as a desiccant and defoliant in agriculture, and as a byproduct of the smelting of nonferrous metals, particularly gold and copper, from coal residues (Hall, 2002). 

There are many acidic oxide gases that react with refractories. They are oxides of nitrogen and sulfur. The nitrates produced by oxides of nitrogen have low melting points. SO2 and SO3 form liquid sulfates. Volatile oxides of arsenic are encountered in some nonferrous metal operations, and are corrosive. The volatile basic oxides are the alkalis K2O and Na20, and their corresponding hydroxides KOH and NaOH. These react with the refractories that contain them and yield products that are almost always low-melting. 

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