Zinc carbonate

Zinc carbonate and zinc oxide are constituents of calamine lotion. Zinc oxide, an antiseptic, is present in zinc ointment and in cosmetic powders. 

Sillimanite, see Aluminum silicon oxide (1/1) Smithsonite, see Zinc carbonate Soda ash, see Sodium carbonate Spelter, see Zinc metal Sphalerite, see Zinc sulflde Spherocobaltite, see Cobalt(II) carbonate Spinel, see Magnesium aluminate(2—)... 

Zincite, see Zinc oxide Zincosite, see Zinc sulfate Zincspar, see Zinc carbonate Zirconia, see Zirconium oxide... 

For increased solubiHty to prevent bloom, shorter-chain carboxyHc acids or zinc carboxylates can be substituted. The use of chain-branched carboxyHc acids reduces the tendency for the formulations to lose sulfur cross-links or revert upon prolonged heating (7). Translucent articles such as crepe soles can use a zinc carboxylate or employ zinc carbonate as a transparent zinc oxide. 

RoUed-zinc products in the form of strip, sheet, wire, and rod have many and varied commercial appUcations. Strip is formed into dry-ceU battery cans, mason jar covers, organ pipes, grommets, eyelets, and many other objects, some of which are subsequentiy brass or chromium plated (jewelry, medaUions, bathroom accessories, etc) (132). The zinc—carbon dry-ceU appUcation accounts for about one half the roUed-zinc consumption in the United States (see Batteries). Sheet zinc is used in photoengraving and also in the constmction of roofing and other architectural uses. Special high grade zinc with a... 

Properties of zinc salts of inorganic and organic salts are Hsted in Table 1 with other commercially important zinc chemicals. In the dithiocarbamates, 2-mercaptobenzothiazole, and formaldehyde sulfoxylate, zinc is covalendy bound to sulfur. In compounds such as the oxide, borate, and sihcate, the covalent bonds with oxygen are very stable. Zinc—carbon bonds occur in diorganozinc compounds, eg, diethjizinc [557-20-0]. Such compounds were much used in organic synthesis prior to the development of the more convenient Grignard route (see Grignard reactions). 

Reactant for /-butyl phenolic resins. Magnesium oxide reacts in solution with /-butyl phenolic resin to produce an infusible resinate (Fig. 36) which provides improved heat resistance. The resinate has no melting point and decomposes above 200°C. Although oxides of calcium, lead and lithium can also be used, they are not as efficient as magnesium oxide and also tend to separate from solution. Where clear adhesive solutions are required epoxide resins, zinc-calcium resinates or zinc carbonate can be used. 

Zink-jodid, n. zinc iodide, -kalk, m. zinc calx, zinc ash. -kastea, m. zinc case zinc tank, -kiesel, m., -kieselerz, n. (siliceous) calamine. -kitt, m. zinc cement, -kohlea-batterie, /. zinc-carbon battery, -legierung, /. zinc alloy, -losung, /. zinc solution, -mehl,... 

French chemist Georges Lcclanchc invents the zinc-carbon battery, a precursor of the diy cell and the modern portable batteiy. 

Zinc compounds such as zinc oxide and basic zinc carbonate are used in some drilling fluids. Their function is to react out swiftly sulfide and bisulfide ions... 

Carbon dioxide was once thought essential for the rusting of ferrous metals (viz. the carbonic acid theory of rusting) but is now considered of relatively minor importance . However, basic zinc carbonate is frequently found in the corrosion products of zinc and small amounts of siderite (FeCOs) are found in ferrous rusts. 

Zinc coatings on steel (galvanised) are attacked in the same way Jis iron, but usually more slowly. Very alkaline waters are usually aggressive to zinc and will often remove galvanised coatings the corrosion products consist of basic zinc carbonate or other basic compounds and may take the form of a thick creamy deposit or hard abrjisive particles. 

In dry air, a film of zinc oxide is initially formed by the influence of the atmospheric oxygen, but this is soon converted to zinc hydroxide, basic zinc carbonate and other basic salts by water, carbon dioxide and chemical impurities present in the atmosphere. 

In dry air the stability of zinc is remarkable. Once the protective layer of zinc oxide formed initially is complete, the attack ceases. Even under under normal urban conditions, such as those in London, zinc sheet 0 -8 mm thick has been found to have an effective life of 40 years or more when used as a roof covering and no repair has been needed except for mechanical damage. The presence of water does, of course, increase the rate of corrosion when water is present the initial corrosion product is zinc hydroxide, which is then converted by the action of carbon dioxide to a basic zinc carbonate, probably of composition similar to ZnCOj 3Zn(OH)2 . In very damp conditions unprotected zinc sometimes forms a loose and more conspicuous form of corrosion product known as wet storage stain or white rust (see p. 4.171). 

Feitknecht has examined the corrosion products of zinc in sodium chloride solutions in detail. The compound on the inactive areas was found to be mainly zinc oxide. When the concentration of sodium chloride was greater than 0-1 M, basic zinc chlorides were found on the corroded parts. At lower concentrations a loose powdery form of a crystalline zinc hydroxide appeared. A close examination of the corroded areas revealed craters which appeared to contain alternate layers and concentric rings of basic chlorides and hydroxides. Two basic zinc chlorides were identified, namely 6Zn(OH)2 -ZnClj and 4Zn(OH)2 ZnCl. These basic salts, and the crystalline zinc hydroxides, were found to have layer structures similar in general to the layer structure attributed to the basic zinc carbonate which forms dense adherent films and appears to play such an important role in the corrosion resistance of zinc against the atmosphere. The presence of different reaction products in the actual corroded areas leads to the view that, in addition to action between the major anodic and cathodic areas as a whole, there is also a local interaction between smaller anodic and cathodic elements. 

Table 13.5 Solubility in water of cadmium and zinc carbonates and hydroxides...

The demand for electrically operated tools or devices that can be handled independently of stationary power sources led to a variety of different battery systems which are chosen depending on the field of application. In the case of rare usage, e.g., for household electric torches or for long-term applications with low current consumption, such as watches or heart pacemakers, primary cells (zinc-carbon, alkaline-manganese or lithium-iodide cells) are chosen. For many applications such as starter batteries in cars, only rechargeable battery systems, e.g., lead accumulators, are reasonable with regard to costs and the environment. 

Zinc/carbon and alkaline/manganese cells are primary battery systems lead, nickel/cadmium, and nickel/metal hydride accumulators are secondary batteries with aqueous electrolyte solutions. Their per-... 

Mn02 is used for the same purpose as the cathode active material in lithium-manganese dioxide (Li - Mn02) batteries it has been used for a long time in zinc-carbon and alkaline-manganese dioxide batteries, which are aqueous-electrolyte systems. 

K. Kordesch, C. Fabjan, J. Daniel-Ivad, J. Oliveira, Zinc-carbon-hybrid systems, Power Sources Conf. Brighton, April 1997. 

Zinc/carbon (Leclanchc cell) Electrode additive, current collector... 

BM Mixture-zinc, carbon tetrachloride, sodium chloride, amm chloride magnesium carbonate... 

Many carbonate, sulfite, and sulfide precipitates can be dissolved by the addition of acid, because the anions react with the acid to form a gas that bubbles out of solution. For example, in a saturated solution of zinc carbonate, solid ZnCO, is in equilibrium with its ions ... 

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