Copper wood preservative

Synonyms CCA Chromated copper arsenate Copper arsenate, chromated Uses Wood preservative Copper chromite... 

More than two-thirds of the naphthenic acid produced is used to make metal salts, with the largest volume being used for copper naphthenate, consumed in the wood preservative industry (see Wood). Metal salts used as paint driers accounted for only 16% of the naphthenic acid market in 1993 (see Paint). This is a dramatic contrast with 1977 usage, when 75% of the naphthenates went into the paint drier market. An overall view of the 1993 naphthenic acid market in North America shows the following uses ... 

Wood preservatives ate appHed either from an oil system, such as creosote, petroleum solutions of pentachlorophenol, or copper naphthanate, or a water system. Oil treatments ate relatively inert with wood material, and thus, have Htde effect on mechanical properties. However, most oil treatments require simultaneous thermal treatments, which ate specifically limited in treating standards to preclude strength losses (24). 

The commercial uses of arsenic compounds in 1988, measured in terms of elemental arsenic, are wood (qv) preservatives, 69% agricultural products (herbicides (qv) and desiccants (qv)), 23% glass (qv), 4% nonferrous alloys and electronics, 2% and animal feed additives and pharmaceuticals (qv), 2% (see Feeds AND feed additives). Chromated copper arsenate (CCA) [11125-95-4] is the most widely used arsenic-based wood preservative. The Environmental Protection Agency has, however, restricted the use of arsenical wood preservatives to certified appHcators. 

Wood Preservation. The use of chromium compounds ia wood preservation is largely because of the excellent results achieved by chromated copper arsenate (CCA), available ia three modifications under a variety of trade names. The treated wood (qv) is free from bleeding, has an attractive ohve-green color, and is paintable. CCA is widely used, especially ia treating utility poles, bull ding lumber, and wood foundations. About 62% of all the chromic acid produced ia the United States is consumed by the wood preservation industry (77,167) (see Building materials, survey). 

Wood preservatives appear not to affect emission of corrosive vapours from wood, suggesting that the hydrolysis of acetyl polysaccharides is chemical, not biochemical. Some copper-base preservatives can give enough leachable copper ions to cause galvanic corrosion of other metals, notably aluminium and steel. 

Copper sulfate can be described as a by-product of copper refining that is obtained by crystallization of the weak liquor. The copper sulfate precipitate formed is centrifuged, dried, screened, and finally packaged in bags and drum. However, it is produced in some chemical industries by reacting copper shot with sulfuric acid, air, and water. It is widely used as an insecticide, additive nutrients (for soils that are deficient in copper), copper electroplating, wood preservation, and in petroleum refining. 

Weis, P., J.S. Weis, and J. Couch. 1993a. Histopathology and bioaccumulation in oysters Crassostrea virginica living on wood preserved with chromated copper arsenate. Dis. Aquat. Organ. 17 41 -46. 

Henningsson, B. and Carlsson, B. (1984). Leaching of copper, chrome and srsenic from preservative-treated timber in playground equipment. International Research Group on Wood Preservation, Doc. No. IRGAVP 3149. 

Kazi, E.K.M. and Cooper, P.A. (2002). Rapid extraction oxidation process to recover and reuse copper chromium and arsenic from industrial wood preservative sludge. Waste Management, 22(3), 293-301. 

Zinc sulfate (ZnSO ZH O) is also known as zinc vitriol or white copper. In addition to being used to make rayon, zinc sulfate is used as a wood preservative, a dietary supplement, an animal feed, and as a mordant to prevent dyes from running in printed textiles. It can also be used to stanch bleeding. 

Uses/Sources. In wood preservatives metallurgy for hardening copper, lead, alloys pigment production manufacture of certain types of glass insecticides and fungicides, rodent poison a by-product in the smelting of copper ores dopant material in semiconductor manufacmre... 

The neutral and basic forms of copper(ll) chromate are used as mordants in dyeing textiles as fungicides to protect textiles from damage by microorganisms and insects and as wood preservatives. 

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