Apatite phosphorus

Phosphorous occurs in nature in several forms, mostly as phosphates. The most common source is phosphate rock [Caj(PO )j] and a mineral called apatite. Phosphorus is found in all animal bones and teeth and in most living tissue. Phosphorous nodules are found on the ocean floor along with manganese nodules. 

Apatite phosphorus That fraction of the total phosphorus concentration that is in the form of apatite. 

Phosphorus fin t discovered in a mineral by J. G. Gahn (pyroinorphitc, a lead phosphate) subsequently found in the much more abundant apatite by T. Bergman and J. L Proust. 

Phosphorus is the eleventh element in order of abundance in crustal rocks of the earth and it occurs there to the extent of 1120 ppm (cf. H 1520 ppm, Mn 1060 ppm). All its known terrestrial minerals are orthophosphates though the reduced phosphide mineral schrieber-site (Fe,Ni)3P occurs in most iron meteorites. Some 200 crystalline phosphate minerals have been described, but by far the major amount of P occurs in a single mineral family, the apatites, and these are the only ones of industrial importance, the others being rare curiosities. Apatites (p. 523) have the idealized general formula 3Ca3(P04)2.CaX2, that is Caio(P04)6X2, and common members are fluorapatite Ca5(P04)3p, chloroapatite Ca5(P04)3Cl, and hydroxyapatite Ca5(P04)3(0H). In addition, there are vast deposits of amorphous phosphate rock, phosphorite, which approximates in composition to fluoroapatite. " These deposits are widely... 

Phosphorus is obtained from the apatites, which are mineral forms of calcium phosphate, Ca (P04)2. The rocks are heated in an electric furnace with carbon and sand ... 

Inorganic reactions in the soil interstitial waters also influence dissolved P concentrations. These reactions include the dissolution or precipitation of P-containing minerals or the adsorption and desorption of P onto and from mineral surfaces. As discussed above, the inorganic reactivity of phosphate is strongly dependent on pH. In alkaline systems, apatite solubility should limit groundwater phosphate whereas in acidic soils, aluminum phosphates should dominate. Adsorption of phosphate onto mineral surfaces, such as iron or aluminum oxyhydroxides and clays, is favored by low solution pH and may influence soil interstitial water concentrations. Phosphorus will be exchanged between organic materials, soil inter-... 

Despite its relatively late discovery, phosphorus is the eleventh most abundant element in Earth s crustal rock. It has been estimated that world reserves of phosphate rock are sufficient to last for several hundred years. Virtually all phosphorus deposits contain apatite, whose general formula is Caj (P04)3 X, where X — OH, or Cl. Fluoroapatite is the least soluble, hence most abundant, of the three apatite minerals. Phosphorus Is found in aqueous systems as HPOq and H2 PO4 ions. In biological organisms, phosphorus is a component of nucleic acids and energy-shuttling molecules such as ATP. 

It is probable that the prevalent oxidation states of phosphorus on the young Earth were lower than they are today, so calcium salts with a much better solubility than that of apatite could have been formed. As Glindemann et al. (1999) were able to show in model experiments, up to 11 % of the starting material could be converted to phosphite in CH4/N2 atmospheres (10% CH4) using Na2HP04, hydroxyapatite or fluoroapatite sources. Similar processes cannot be excluded for the primeval Earth, for example, under the influence of electrical discharges. 

Takadama, H., Hashimoto, M., Mizuno, M. and Kokubo, T. (2004) Round-robin test of SBF for in vitro measurement of apatite-forming ability of synthetic materials. Phosphorus Research Bulletin, 17, 119-25. 

Phosphorus compounds occur widely in nature, with some of the most common forms being phosphate rocks and minerals, bones, and teeth. Phosphate minerals include calcium phosphate, Ca3(P04)2 apatite, Ca5(P04)30H fluoroapatite, Ca5(P04)3F and chloroapatite, Ca5(P04)3Cl. Elemental phosphorus was first obtained by H. Brand, and its name is derived from two Greek words meaning "light" and "I bear" because of the phosphorescence of white phosphorus due to slow oxidation. 

Apatite exploration takes place in various regions of the World, and the most known are Kola Peninsula (Russia) and northwest Africa (Morocco). In both places, the apatite ores contain not only phosphorus as a main element but also many heavy metals, which are toxic for humans and animals. The given elements are F, As, Y, some rare earth species, Sr, Pb, Cd, Sn. The underground waters in these regions are enriched by F, Fi, Nb, some rare earth species with alkaline reaction that facilitates the migration of many ore elements. Some phosphorus containing ores are radioactive owing to the mixtures of uranium and thorium. 

Occurrence. Widely distributed in many minerals (more than 200 minerals are known). Commercial sources of phosphorus are apatites (for instance fluoroapatite [3Ca3(P04)2 Ca(F,Cl)2]). 

It is well known that vanadium can replace phosphorus or arsenic in the apatite lattice. Most of the orthovanadates which crystallize in this form have been investigated by IR and Raman spectroscopic techniques 62—64). The results of these studies are summarized in Table 4. The space group of all of these compounds is certainly C ft with the VO4 ion lying on a C site. Therefore, one should always find a nine band spectrum. Phosphorus apatites behave similarly, as seen in Ref. (65). 

Apatite and phosphorus in mantle source regions an experimental study of... 

The use of H NMR to investigate the structure of fluoridated apatite appears to be of crucial importance, particularly for determining the active surface sites, suggested to be calcium hydroxyl (Ca-OH) and phosphorus (POH) groups [51],... 

Ninety five percent of the phosphorus on Earth belongs to the minerals of the apatite group. Apatites are inorganic constituents of bones and teeth of vertebrate and man, as well as a basis of many pathologic sohd formations. Minerals of the apatite group are the main raw materials in the production of phosphorus fertilizers, fodder and technical phosphates, elementary phosphorus, and phosphor-organic compounds. The mineral is sometimes substantially enriched in rare-earth elements (REE) making their extraction possible (Altshuller 1980). 

Cerium in Plants and Animals. Professor Alfonso Cossa, finding the rare earths of the ceria series to be present in many apatites, and realizing the close association in nature between these earths and calcium and phosphorus, tested for them and detected their presence in bone (66). He also detected them in the ash of barley, beech wood, and tobacco. With the aid of C. Schiapparelli and G. Peroni of the University of Turin, he demonstrated their presence in human urine (66, 67, 68). 

The apatite group minerals are the most abundant phosphorus-bearing minerals on Earth, typically as accessory minerals in basic to acidic igneous rocks, pegmatites, hydrothermal veins and cavities, carbonates, contact and regionally metamorphosed rocks, and sedimentary rocks (Deer et al. 1996). The principal members of the apatite group include fluoroapa-tite (Ca5(P04)3F), chloroapatite (Ca5(P04)3Cl), hydroxyapatite, and carbonate apatite (Ca5(P04, C03)3(F,0H)) (Deer et al. 1996). 

Tricalcium Phosphate. CarlPOjij. white solid, insoluble in water, reactive with silicon oxide and carbon ai eleciric furnace temperaiure yielding phosphorus vapor reactive with H1SO4 to form, according tn the proportions used, phosphoric acid, or dicalcium hydrogen phosphate, CaHPOa, white solid, insoluble or calcium dihydrogen phosphate, Cal 1L POrb- H O. white solid, soluble. pK,p = 28.70. See also Apatite. 

Phosphorites (manne apatites) are dense, hght-brown-to-black concretions, ranging in size from sands to nodules and irregular masses. Phosphorites have been found off Argentina, Chile, Japan, Mexico, Peru, South Africa, and Spain, and several islands in the Indian Ocean. Some also have been found off the west coast of North America and on the eastern North American continental shelf These deposits occur where water upwelling transports phosphorus and where the rate of sedimentation is slow. The... 

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