| WATER PURIFICATION Lime is used in water treatment for precipitation, to raise the pH, and to adjust the hardness of the water. Raw water taken from municipal surface water or groundwater sources is purified and treated at a water treatment plant before it reaches the consumer. The water is treated differently depending on the quality of the raw water. Lime products are often used in these contexts to raise the pH value of the water. Adding slaked lime induces precipitation of non-desired substances, such as humus, particles, and metals. Research shows that minerals have a good effect on our health, especially calcium and magnesium supplements. Slaked lime in combination with carbon dioxide is added to soft water from municipal sources to raise the alkalinity and the total hardness. |
 Another method is to let the water filter through a bed of limestone CaCO3 or dolomite CaMg(CO3)2. This protects water- and sewerage lines that require non-corrosive water. With the health aspect in the background, here is another argument for using a natural product for water treatment. Slaked lime can also be used to soften water and reduce its carbonate hardness Ð a method that has long been known in areas with hard water. |
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 FLUE GAS CLEANING Modern waste combustion had its breakthrough in the 1960s and 1970s. It was not long before plants were faced with emission requirements, leading to major investments in highly sophisticated flue gas cleaning technology to minimize impact on our environment. Many cleaning methods are available today, but lime products are included in most of them. The methods can be divided into three main groups: dry, wet-dry, and wet. Dry Method Lime is added to the flue gases either in the furnace or in the flue. Water is sprayed on the flue gases to cool and vaporize them. After that dry slaked lime Ca(OH)2 is added to the flue gases to bind acidic components such as HCl, HF, SO2, and SO3. A dry product is formed that is mixed with fly ash, which is captured by a downstream filter. If combustion of the waste takes place in a fluidized bed, lime can be added through a separate infeed in an unrefined form such as limestone, CaCO3, or dolomite, CaMg(CO3)2. |
Wet-dry Method The flue gas is sprayed in a reactor with a slurry consisting of lime mixed with water. The slurry dries at the same time that it reacts with the acidic elements in the flue gases. A filter captures the particles in the flue gases most effectively. This method can use either burnt or slaked lime. The lime is used most efficiently, however, by using burnt lime and slaking it on site. Wet Methods In one wet method the flue gas is washed with water in a column or in a scrubber. In the other wet cleaning method, the flue gas is cooled enough for the vapor to convert from the gaseous phase to the liquid phase. This liquid phase, or condensation, contains many pollutants and must therefore be cleaned before release. Lime is used in the cleaning process to neutralize the condensed material. After that the pollutants are precipitated using a flocculent, which is disposed of later. Adding lime and active carbon substantially contributes to the separation of dioxins, mercury, and sulfur dioxides. |
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| < WATER PURIFICATION < FLUE GAS CLEANING |
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SMA_Water_GB.pdf (890 kb) |
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SMA_Flue_gas_GB.pdf (760 kb) |
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MSDS - Burned Dolomite.pdf (130 kb) |
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MSDS - Burnt lime.pdf (140 kb) |
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MSDS - Slaked lime.pdf (140 kb) |