Kalkkia

Kalkkia, commonly referred to as lime, is a family of calcium-containing materials derived primarily from limestone or chalk. The principal forms are natural limestone or chalk (mainly calcium carbonate, CaCO3), quicklime (calcium oxide, CaO) produced by calcination, and hydrated lime (calcium hydroxide, Ca(OH)2) formed by adding water to quicklime. Limestone and chalk occur as rocks and powders; heating limestone releases carbon dioxide and leaves quicklime. When quicklime is mixed with water, it forms slaked lime, which can carbonate again upon exposure to carbon dioxide.

In agricultural and environmental contexts, kalkkia is used to neutralize acidic soils, raise soil pH, and improve nutrient availability, while supplying calcium to plants. Dolomitic lime, which contains magnesium, is used when magnesium is also deficient. In water treatment, lime adjusts pH and aids in removing impurities through precipitation of hardness and other contaminants. In construction and restoration, lime has been used in mortars, plasters, and whitewash. Lime-based products such as hydraulic lime and lime-putty mortars are valued for vapor permeability and compatibility with historic structures.

Safety and environmental considerations are important. Quicklime is highly reactive with water and can cause severe burns; hydrated lime is caustic, requiring appropriate personal protective equipment during handling. Lime production and quarrying entail energy use and CO2 emissions from calcination, along with potential landscape and dust impacts. Proper management, dosing, and site restoration mitigate environmental effects, while correct application in soils and water treatment can yield long-term benefits for agriculture and ecosystems.

See also: cement, lime mortar, calcium oxide, calcium hydroxide, soil pH.