LIME CALCINATION PLANT

Quick lime which is also known as calcium oxide or burnt lime specifically for chemical industries. Quick lime/burnt lime is obtained by calcining pure limestone at high temperature.

Quick lime is used in mortar and plaster, in glass production and in metal production industries to remove impurities.

The elements calcium and magnesium that abound so widely in the earth’s crust, most commonly occur in carbonate forms of rock, generally classified as lime stone. Chemically it is composed primarily of calcium carbonate, CaCO3, including varying percentage of impurities. Although these carbonates may occur in many other rocks areas and soils in its broadest interpretation a chemical prerequisite for lime stone is that it contains greater than 50% carbonate.

Lime stones most important chemical characteristic is that when subjected to high temperature, it decomposes chemically into lime, CaO decarbonation occurring through the expulsion of CO2 gas. This primary product, known as quicklime, may be dehydrated or slaked into hydrated lime, calcium hydroxide (Ca(OH)2, the water being chemically complete bined with calcium oxide in an unimolar ratio.

It occurs in varying degrees in nearly every country. It is one of the most bare raw materials employed in industry and construction and has been compared to one leg of a six legged stool around which modern industry revolves, the other legs being coal, oil, iron ore, sulphur and salt.

Lime is one of the oldest chemicals known to man; the process of lime burning is one of the oldest chemical industries. Lime plaster and mortar were used by the Greeks, Romans, Etruscaus, Arabian and Moors. Vitruvious, a Roman Architect under Augustus, wrote the first detailed lime Specifications.

Calcium oxide is also known as lime quicklime, burnt lime, calx, unslaked lime, fluxing lime.

It is a white or gregish white hard lumps, sometimes with a yello with or burnish tiut due to iron.

Regarding its production, calcium carbonate (lime stone) is roasted in limes until all the carbon dioxide is driven off.

The impurities present in calcium carbonate, magnesium, iron and aluminium oxides. Compared to one leg of a six legged stool around which modern industry revolves, the other legs being coal, oil, iron ore, sulphur and salt.

• Calcium oxide (CaO), commonly known as burnt lime, lime or quicklime, is a widely used chemical compound. It is a white, caustic and alkaline crystalline solid. As a commercial product lime often also contains magnesium oxide, silicon oxide and smaller amounts of aluminium oxide and iron oxide.

• Calcium oxide is a crystalline solid. Its crystal structure is Isometric with space group Fm3m. It is generally unstable when 553 moisture is present and exhibits a large exothermic reaction with water to form aqueous Ca(OH)2.

• Calcium oxide is produced by heating calcium carbonate to 2000 deg F where carbon dioxide disassociates as a gas from the calcium carbonate.

• CaO is representative of group II oxides (MgO, SrO etc). It can be prepared by intense roasting of the corresponding carbonate or hydroxide. The formation is reversible in the presence of CO2 or H2O, respectively.

• A lime process mainly contains the following basic steps: Winning of limestone, Limestone storage and preparation, Fuels storage and preparation, Calcinations of limestone, Quicklime processing, Quicklime hydration and slaking, Storage, handling and transport.

• More than 90% of the lime (burned or hydrated) produced in the United States is used for basic or industrial chemistry. The primary use is for steel manufacture (30%), metallurgy, air pollution control and water and sewage wastewater treatment (24%), cement and mortar, chemical manufacture, manufacture of glass and paper, diluents and carriers of pesticides such as lime-sulfur and Bordeaux mixture, and bleach production and other chemical manufacture.

• Lime typically sells for A$100 to A$120 per ton implying a total value of production of $80m. Import competition largely decides the price of lime.

• The lime industry is a captive industry to Western Australia. Lime producers are competitive through ready access to limestone, cheap energy, economies of scale and in particular by international freight that acts as a barrier to trade in both directions for this low value product. Though import competition serves mainly to determine local prices, it is possible if not probable, that the quality of lime produced in Western Australia will increase with increasing demand from resource companies especially those close to north western ports where import competition is inevitably greatest and with the future supply of higher grade lime from Swan Portland Cement.