Calcium phosphate
Calcium phosphate is the name given to a family of minerals containing calcium ions (Ca2+) together with orthophosphates (PO43−), metaphosphates or pyrophosphates (P2O74−) and occasionally hydrogen or hydroxide ions.
Calcium phosphate is the principle form of calcium found in bovine milk and blood. Seventy percent of bone consists of hydroxyapatite, a calcium phosphate mineral (known as bone mineral). Tooth enamel is composed of almost ninety percent hydroxyapatite.
Unlike most other compounds, the solubility level of calcium phosphate becomes lower as temperature increases. Thus heating causes precipitation.
In milk it is found in higher concentrations than would be possible at the normal pH because it exists in a colloidal form in micelles bound to casein protein with magnesium, zinc and citrate - collectively referred to as colloidal calcium phosphate (CCP).
It is used in the production of phosphoric acid and fertilizers, for example in the Odda process. Overuse of certain forms of calcium phosphate can lead to nutrient-containing surface runoff and subsequent adverse effects upon receiving waters such as algal blooms and eutrophication.
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