Slaked lime, chemically known as calcium hydroxide, is an inorganic compound with the chemical formula Ca(OH)₂.
It is produced by the reaction of calcium oxide (quicklime, CaO) with water; this reaction process is also known as the slaking or digestion of lime. Slaked lime is a white, powdery solid at room temperature and is slightly soluble in water; its aqueous solution is called limewater and is alkaline.
From a compositional perspective, the main component of slaked lime is calcium hydroxide, a strong alkali with corrosive properties. In industrial production, the purity of slaked lime varies depending on the production process and its intended use, but generally, high-quality slaked lime has a relatively high calcium hydroxide content. Besides calcium hydroxide, slaked lime may also contain small amounts of unreacted calcium oxide, water, and possible impurities such as silica, alumina, and iron oxide. The content of these impurities is usually low and varies depending on the raw materials and production process.
Slaked lime has wide applications in many fields. In the construction industry, slaked lime is a crucial raw material for preparing building materials such as lime mortar, lime slurry, and lime-soil. In the environmental protection field, due to its alkaline properties, slaked lime is widely used in wastewater treatment and flue gas desulfurization projects to neutralize acidic wastewater or exhaust gases and reduce environmental pollution. Furthermore, slaked lime is used in agriculture as a soil conditioner to neutralize soil acidity and improve soil fertility. In the chemical industry, slaked lime is also an important raw material for preparing other calcium compounds, such as calcium carbonate and calcium chloride.
When using slaked lime, it is important to be aware of its strong alkalinity and corrosiveness, and to avoid direct contact with skin and eyes to prevent harm. Slaked lime must also be kept dry during storage and transportation to prevent it from absorbing moisture, clumping, or deteriorating. In industrial production, it is necessary to select slaked lime products of appropriate purity and quality based on specific application scenarios and requirements to ensure its effectiveness and safety.
