Kalkkiahydroksidi

Kalkkiahydroksidi, known in English as calcium hydroxide and chemically Ca(OH)2, is a white, odorless solid widely used as a base and lime in various industries. It is produced by hydrating calcium oxide (quicklime) with water: CaO + H2O → Ca(OH)2. In water it creates a strongly alkaline solution, typically with a pH around 12.5, though only a portion dissolves; the remainder stays as a solid.

Calcium hydroxide occurs as solid hydrated lime or as a suspension known as milk of lime. It is commonly sold as hydrated lime, lime putty, or in ready‑to‑use slurries for construction, water treatment, and agriculture. The solid is relatively sparingly soluble in water and reacts with carbon dioxide in air to form calcium carbonate over time.

Key chemical properties include high basicity and reactivity with acids to form calcium salts, and carbonation with CO2 to CaCO3. It readily neutralizes acids and can increase soil pH, making it useful for agricultural lime applications. In water and wastewater treatment, it is used to adjust pH, precipitate metals, and aid in softening processes.

Major applications span construction (lime mortars and plasters), agriculture (neutralizing acidic soils and supplying calcium), food processing (nixtamalization of corn and other pH-related processes), and environmental engineering (pH control and metal precipitation). It is also used in paper and chemical industries as a pH regulator and in various industrial reactions.

Safety considerations include its caustic nature, which can irritate skin and eyes; proper handling, protective equipment, and storage away from moisture and CO2 are advised to maintain quality and safety.