Calcium fluorophosphate

In the geochemistry of fluorine, the close match in the ionic radii of fluoride (0.136 nm), hydroxide (0.140 nm), and oxide ion (0.140 nm) allows a sequential replacement of oxygen by fluorine in a wide variety of minerals. This accounts for the wide dissemination of the element in nature. The ready formation of volatile silicon tetrafluoride, the pyrohydrolysis of fluorides to hydrogen fluoride, and the low solubility of calcium fluoride and of calcium fluorophosphates, have provided a geochemical cycle in which fluorine may be stripped from solution by limestone and by apatite to form the deposits of fluorspar and of phosphate rock (fluoroapatite [1306-01 -0]) approximately CaF2 3Ca2(P0 2 which ate the world s main resources of fluorine (1). 

Yellow phosphorus (known also as white phosphorus) is produced by reducing phosphate rock (calcium phosphate or calcium fluorophosphate) with carbon in the presence of silica as flux heat of reaction is furnished by an electric-arc furnace. 

The major deposits of phosphate ores are in Florida in the United States, Kola in Russia, and Morocco [2,3]. They consist of minerals of calcium and aluminum phosphates [2]. These ores are processed to extract these minerals the most important among these minerals is calcium fluorophosphate (CaioF2(P04)6). Richness of phosphate in these rocks and the extracted products is measured in terms of P2O5 content in them. 

Ryan FM, Ohlmann RC, Murphy J, Mazelsky R, Wagner GR, Warren RW (1970) Optical properties of divalent manganese in calcium fluorophosphate. Phys Rev B 2 2341-2352 Scott MA, Han TPJ, Gallagher HG, Henderon B (1997) Near-infrared laser crystals based on 3cf ions Spectroscopic studies of ions in oxide, melilite and apatite crystals. J Lumin 72-74 260-262 Sears DWG (1980) Thermoluminescence of meteorites Relationships with their K-Ar age and their shock and reheating history. Icarus 44 190-206... 

Warren RW (1970) EPR of Mn in calcium fluorophosphates. 1. The Ca (11) site. Phys Rev B 2 4383-4388 Waychunas G (1989) Luminescence, X-ray emission and new spectroscopies. Rev Mineral 18 638-698 Wright AO, Seltzer MD, Graber JB, Zandi B, Merkle LD, Chai BHT (1996) Spectroscopic investigation of Pr in fluorapatite crystals. JPhys Chem Solids 57 1337-1350 Xiong J (1995) Cathodoluminescence studies of feldspars and apatites from the Coldwell alkaline complex. MSc thesis, Lakehead Univ, Thunder Bay, Ontario... 

Synonyms Calcium fluorophosphate Calcium phosphorofluoridate Phosphorofluoridic acid, calcium salt... 

Ryan F, Ohlmann R, Murphy J et al (1970) Optical properties of divalent manganese in calcium fluorophosphate. Phys Rev B 2 2341-2352... 

More than 99% of the body s calcium is present in bone as calcium fluorophosphate apatite. Calcium is also involved in neuromuscular excitability and nervous impulse transmission, blood coagulation and in the transfer of inorganic ions across cell membranes. 

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