Kapur

Kapur is the Indonesian and Malay term for limestone as well as for lime products derived from it. Limestone is a sedimentary rock dominated by calcium carbonate (CaCO3), usually in the form of calcite or dolomite, and often contains impurities such as silica, clay, iron oxide, and organic matter that influence color and purity. The term covers both the rock and manufactured materials such as quicklime (calcium oxide, CaO) and its hydrated form, slaked lime (calcium hydroxide, Ca(OH)2).

Formation and occurrence: Limestone forms from the accumulated shells and skeletons of marine organisms, through chemical precipitation, or via diagenetic processes. It is widely distributed worldwide, especially in regions with karst landscapes. Many countries hold substantial limestone reserves, supporting quarrying, cement, and lime industries.

Processing and types: Limestone is quarried and processed into aggregates for concrete and road building. Calcination in kilns converts limestone to quicklime, which can be hydrated to produce slaked lime. Limestone rock is also crushed into powders and granules for cement and filler applications; certain varieties, like chalk, are softer forms of limestone used in specific industries.

Uses: In construction, limestone serves as a building stone and as a raw material for cement and lime plaster. Lime products are used to neutralize acidic soils, supply calcium, and treat drinking water and wastewater. In industry, lime acts as a flux in steelmaking and participates in various chemical processes.

Environment and safety: Limestone quarrying and lime production can cause habitat disturbance, dust, and water management concerns. Lime products are caustic and can cause skin or eye irritation; proper handling and protective equipment are recommended.