Calcium Oxide
CALCIUM OXIDE or QUICKLIME
Chemical lime is a term designating a type of quick or hydrated lime (see calcium hydroxide)
Calcium hydroxide : low in impurities and possessing a high degree of reactivity making it suitable for use in chemical processes. Commercially, chemical lime is obtained through the controlled calcination of high quality limestone. Quicklime, the product of calcination, consists of the oxides of calcium and magnesium, and in this country it is available in three forms.
High calcium quicklime : containing usually 0.5 to 2.5 percent magnesium oxide.
Dolomitic quicklime : containing usually 35 to 40 percent magnesium oxide.
Magnesium quicklime : containing usually 5 to 10 percent magnesium oxide.
Chemical lime is a white solid having a crystalline structure. Quicklime is highly reactive with water, generating considerable heat in the hydration process. This material will react with the moisture in the air, and as such, it has found application as a desiccant. In the presence of moisture, the lime reacts slowly with the carbon dioxide of the air, forming water insoluble carbonates. As a chemically active material it is desirable to reduce atmospheric exposure during handling and storage to a minimum.
Quicklime is available by the carload, in bulk dump or tanker, and in 50 Ib. paper bags and one ton bulk bags and a number of more or less standard sizes as follows:
Lump lime : the product with a maximum size of eight inches in diameter.
Crusted or pebble lime : the product ranging in size from about 1/4 to 2 inches.
Ground lime : the product resulting from grinding the larger sized material. A typical size is substantially all material passing a No. 8 sieve and 40 to 60 percent passing a No. 100 sieve.
Pulverized lime : the product resulting from a more intense grinding than is used to produce ground lime. A typical size is all material substantially passing a No. 20 sieve and 85 to 95 percent passing a No. 100 sieve
Pelletized lime : one inch sized pellets or briquettes, molded from quicklime fines.
USES OF LIME
METALLURGY: Steel Manufacture, Steel Products Manufacture, Magnesium Manufacture, Alumina Manufacture, Ore Flotation and Non-Ferrous Metal Smelting.
PULP AND PAPER: Sulfate Process, Sulfite Process, Bleaching, Precipitated Calcium Carbonate, Strawboard Manufacture, and in the treatment of pulp and paper mill liquid wastes, as a coagulant in color removal.
CHEMICALS: Alkalis, Calcium Carbide and Cyanimide, Petrochemicals, Bleaches, Dye and Dyestuff Intermediates and Coke-By-Products. In addition, it is used in the purification of citric acid, glucose and dextrin: metallic calcium; soda-lime, an adsorbent; and for countless other minor or isolated purposes, such as for CO2 absorption.
ENVIRONMENTAL USES
WATER TREATMENT: Scope, Softening, Purification, Coagulation, Neutralization of Acid Water, Silica Removal and Removal of Other Impurities
SEWAGE TREATMENT: Maintain proper pH and Stabilizing Sewage Sludge.
INDUSTRIALTRADE WASTES: Treatment of industrial trade wastes to abate pollution from Steel and Metal Fabricating Plants, Chemical and Explosives Plants, Acid Mine Drainage, Paper and Fibers, Food Plants and in clarifying “water gas” acid waste effluents.
FLUE GAS DESULFURIZATION
SOLID WASTES DISPOSAL
CERAMIC PRODUCTS: Glass, Refractories, and in the production of white ware pottery, lime is sometimes employed to bind the kaolin and ball clays present.
BUILDING MATERIALS: Calcium Silicate Brick, Concrete Products, Miscellaneous Building Units, and Insulation Materials.
PROTECTIVE COATINGS: Pigments, Water Paints, and Varnish.
FOOD AND FOOD BY-PRODUCTS: Dairy Industry, Sugar Industry, Animal Glue and Gelatin Industries, Baking Industry, and CA (controlled atmospheric) Storage of Fresh Fruit and Vegetables. All tortillas are made with lime treatment.
MISCELLANEOUS USES: Petroleum, Leather, and Rubber.