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Calcite, the main cause of scale, is the most common
form of calcium carbonate and occurs naturally as a
natural ingredient of chalk, limestone and marble. Water
passing over and permeating through such rocks dissolves
calcite when this water subsequently flows through a
water system the calcite precipitates out to form a very
hard scale on surfaces.
When hard water is heated, or evaporation takes
place, the problems are exacerbated. Calcite forms ever
growing layers of rock-like deposits until eventually
pipes, jets and equipment become totally blocked.
The problem increases as the water gets hotter. Water
containing 145 ppm of calcite, flowing at 3.5 litres per
minute, produces in one year 4.8 kilograms of scale at
60ºC. At 80ºC this rises dramatically to a massive 29.9
kilograms!
Scale wastes both energy and financial resources just
one eighth of an inch of scale reduces heating
efficiency by 25%. It is also very expensive to remove,
de-scaling pipes and boilers alone costs British
Industry over £800M each year.
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