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Wet Storage Stain
Wet storage stain, more commonly known as white rust or white corrosion, is a type of zinc corrosion. It is called wet storage stain because it occurs when a fresh zinc surface is stored in a wet environment with limited oxygen and carbon dioxide sources; the restriction in air is usually due to the items being stacked on one another or otherwise stored in close quarters. This type of corrosion does not usually occur to zinc surfaces that have had time to form their normal layers of corrosion protection.. Chemistry Wet storage stain is a white, crumbly, and porous substance that is a mixture of three chemical compounds: 2ZnCO3·3Zn(OH)2, ZnO, and β-Zn(OH)2. Underneath the white coating is usually a dark gray surface. The corrosion product is very voluminous; it is approximately 100 times greater in volume than the zinc consumed. Because of this the corrosion is not usually detrimental to the usability of the item, unless the zinc surface is only a thin coating, such as zinc elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc
Zinc is a chemical element with the symbol Zn and atomic number 30. Zinc is a slightly brittle metal at room temperature and has a shiny-greyish appearance when oxidation is removed. It is the first element in group 12 (IIB) of the periodic table. In some respects, zinc is chemically similar to magnesium: both elements exhibit only one normal oxidation state (+2), and the Zn2+ and Mg2+ ions are of similar size.The elements are from different metal groups. See periodic table. Zinc is the 24th most abundant element in Earth's crust and has five stable isotopes. The most common zinc ore is sphalerite (zinc blende), a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States. Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity ( electrowinning). Zinc is an essential trace element for humans, animals, plants and for microorganisms and is necessary for prenatal and postnatal development. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
