Hydrated Lime

Hydrated Lime, also known as Calcium Hydroxide, has the appearance of a colourless crystalline powder and is made by treating Calcium Oxide (quicklime) with water, a process known as "ripening". Quicklime, also known as slack lime, building lime or pickled lime, is used in the production of mortar, plaster, cement, paints, hard rubber products, petrochemicals and the tanning of leather.

Hydrated Lime is widely used in the steel, chemical, flue gas treatment, construction, paint and soil industries with the following uses: (1) Used in steel making. Hydrated Lime neutralises impurities in plants in which coke is used as a by-product. Steel plates are often encased in hydrated lime because it acts as an effective short-term barrier to oxygen corrosion.
(2) Chemical production. Hydrated lime is used as a raw material in the manufacture of various other chemicals such as bromides, caustics, fluorides, magnesium oxide, lactates, nitrates, oleates and stearates.
(3) Flue gas treatment. Hydrated lime is a mild alkali used to remove acid gases from coal-fired power plants, cement factories, glass manufacturers and incinerators. Such gases as hydrogen fluoride, hydrogen chloride, sulphur dioxide, selenium and fine particulate matter are captured by the anions of the slaked lime and eventually converted to calcium sulphate.
(4) Manufacture of gypsum and plaster. It combines with sand to form gypsum and mortar. The addition of 15 per cent hydrated lime to cement significantly reduces shrinkage and cracking.

Hydrated Lime has certain effects on human health. Inhalation of high concentrations of Hydrated Lime can cause irritation of the respiratory tract and may have toxic effects on the respiratory system. Skin or eye contact can cause skin irritation and serious eye damage. Prolonged or repeated exposure can cause dermatitis. It can cause burns when wet, gastrointestinal irritation when ingested, etc. Therefore, personal protection should be observed during use.