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Calcium metal is found in some drain cleaners, where it functions to generate heat and calcium hydroxide that saponifies the fats and liquefies the proteins (for example, those in hair) that block drains. [48] Besides metallurgy, the reactivity of calcium is exploited to remove nitrogen from high-purity argon gas and as a getter for oxygen and ...
One of the world's largest deposits of calcrete is in the Makgadikgadi Pans in Botswana, where surface calcretes occur at the location of a now-desiccated prehistoric lake. [12] Highly indurated (hardened) caliche is known as calcrete, and it gives rise to characteristic landforms in arid environments. Calcrete is found throughout the geologic ...
It is the raw material for the manufacture of quicklime (calcium oxide), slaked lime (calcium hydroxide), cement and mortar. [59] Pulverized limestone is used as a soil conditioner to neutralize acidic soils (agricultural lime). [115] Is crushed for use as aggregate—the solid base for many roads as well as in asphalt concrete. [59]
The US Institute of Medicine (IOM) established Recommended Dietary Allowances (RDAs) for calcium in 1997 and updated those values in 2011. [6] See table. The European Food Safety Authority (EFSA) uses the term Population Reference Intake (PRIs) instead of RDAs and sets slightly different numbers: ages 4–10 800 mg, ages 11–17 1150 mg, ages 18–24 1000 mg, and >25 years 950 mg. [10]
China and Italy were the world leaders, each representing 34% and 19% of world production respectively, followed by India and Spain produced 16% and 13% respectively. [ 23 ] In 2018 Turkey was the world leader in marble export, with 42% share in global marble trade, followed by Italy with 18% and Greece with 10%.
Calcium is a mineral found naturally in the body and in multiple food sources, according to Dr. Lee. “Calcium plays a role in bone health to keep it rigid and strong,” she explains.
World Book Encyclopedia, Exploring Earth. HyperPhysics, Georgia State University, Abundance of Elements in Earth's Crust. Eric Scerri, The Periodic Table, Its Story and Its Significance, Oxford University Press, 2007 "EarthRef.org Digital Archive (ERDA) -- Major Element Composition of the Core vs the Bulk Earth". earthref.org
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