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Zinc oxide is an inorganic compound with the formula Zn O.It is a white powder which is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics, ceramics, glass, cement, lubricants, [12] paints, sunscreens, ointments, adhesives, sealants, pigments, foods, batteries, ferrites, fire retardants, semi conductors ...
The remaining calcine is then leached in strong sulfuric acid to leach the rest of the zinc out of the zinc oxide and zinc ferrite. The result of this process is a solid and a liquid; the liquid contains the zinc and is often called leach product; the solid is called leach residue and contains precious metals (usually lead and silver) which are ...
Solutions prepared from dissolving zinc hydroxide or zinc oxide in a strong alkali like sodium hydroxide, which contains various zincate anions, are used in the metal plating industry, in processes such as immersion zinc plating and electroplating (electrogalvanization). Any of these techniques may be called zincate process. [3]
Gases are removed for various reasons. Chemists remove gases from solvents when the compounds they are working on are possibly air- or oxygen-sensitive (air-free technique), or when bubble formation at solid-liquid interfaces becomes a problem. The formation of gas bubbles when a liquid is frozen can also be undesirable, necessitating degassing ...
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
A good example of the autoclave leach process can also be found in the metallurgy of zinc. It is best described by the following chemical reaction: [citation needed] 2 ZnS + O 2 + 2 H 2 SO 4 → 2 ZnSO 4 + 2 H 2 O + 2 S. This reaction proceeds at temperatures above the boiling point of water, thus creating a vapour pressure inside the vessel.
Zinc nitrate is usually prepared by dissolving zinc metal, zinc oxide, or related materials in nitric acid: Zn + 2 HNO 3 → Zn(NO 3) 2 + H 2 ZnO + 2 HNO 3 → Zn(NO 3) 2 + H 2 O. These reactions are accompanied by the hydration of the zinc nitrate. The anhydrous salt arises by the reaction of anhydrous zinc chloride with nitrogen dioxide: [1]
Solutions of sodium zincate may be prepared by dissolving zinc, zinc hydroxide, or zinc oxide in an aqueous solution of sodium hydroxide. [2] Simplified equations for these complex processes are: ZnO + H 2 O + 2 NaOH → Na 2 Zn(OH) 4 Zn + 2 H 2 O + 2 NaOH → Na 2 Zn(OH) 4 + H 2