Calcium phosphide Calcium phosphide Calcium phosphide (CP) is the inorganic compound with the formula CaP. It is one of several phosphides of calcium, being described as the salt-like material composed of Ca and P. Other, more exotic calcium phosphides have the formula CaP, CaP, CaP, and CaP. CaP has the appearance of red-brown crystalline powder or grey lumps. Its trade name is Photophor for the incendiary use or Polytanol for the use as rodenticide. It may be formed by reaction of the elements, but it is more commonly prepared by carbothermal reduction of calcium phosphate: The structure of the room temperature form
Calcium apatite ([Ca(PO)F]). The major producers of calcium are China (about 10000 to 12000 tonnes per year), Russia (about 6000 to 8000 tonnes per year), and the United States (about 2000 to 4000 tonnes per year). Canada and France are also among the minor producers. In 2005, about 24000 tonnes of calcium were produced; about half of the world's extracted calcium is used by the United States, with about 80% of the output used each year. In Russia and China, Davy's method of electrolysis is still used, but is instead applied to molten calcium chloride. Since calcium is less reactive than