Apatite deposition

Phosphate rock, mined widely throughout the world for its fertilizer value (see Fertilizers), in certain regions contains a few percent of lanthanides. For example, the apatite deposits in the Kola peninsula on the Russian/Finnish border. The Ln content is recoverable from the various processing residues, and because other Ln-containing minerals, such as loparite [12173-83-0], are also found there, the location suppHes a significant part of the demand in Eastern Europe. 

Miyazaki, T., Ohtsuki, C., Akioka, Y., Tanihara, M., Nakao, J., Sakaguchi, Y. and Konagaya, S. (2003)Apatite deposition on polyamide films containing carboxyl group in a biomimehc solution. Journal of Materials Science-Materials in Medicine, 14, 569-574. 

Later (Zotov 1980, 1989 Korzhinskii et at. 1984 Marakushev et at. from 2002 up to 2006), it was shown that transmagmatic fluids are able to transport ore metals whose portion may be predominant in endogenic deposits as for example in R-Pd-Cu-Ni sulfide deposits (same ref.), apatite deposits of alkali (Zotov 1989) and alkali-carbonatite (Seredkin et at. 2004) magmatic massifs. This concept is essentially useful as an application for understanding of genesis of big endogenic ore deposits (Zotov 1980). 

Residues from uranium mining operations in Canada have been a major source of yttrium. Xenotime (YPO4) found in Malaysia is another source, as well as the ion-adsorption clay minerals in China. Some apatite deposits are unusually rich in yttrium and it also is found in gadolimte, euxenite, and samarskite. 

Reconstituted acid-soluble collagen from various mineralized and unmineralized tissues have been examined for their potential to pick up calcium and phosphate from buffered solutions, and for their capacity to induce nucleation of a mineral phase426-434. Some collagens were good, others poor catalysts428,429 and apatite deposition proceeded in the presence of soft as well as of hard tissue collagens. The uptake of calcium ions requires the presence of phosphate ions and vice versa the Ca/P ratio is close to that of apatite (1.5—1.8)431. Study of exchange reactions by isotope tracers between solvent und substrate revealed that in absence of either... 

Phosphate containing rock in certain areas contains a few-percent of lanthanides, e. g. the apatite deposits in the Kola peninsula in the Commonwealth of Independent States (C.I.S.). Loparite, a Nb-mincral containing rare-earths is also present and is the leading source of rare-earihs for the C.I.S. [8]. 

Sedimentary apatite deposits are in quantity much more important than the magmatic ones. 

Structure of calcium titanate/titania bioceramic composite coatings on titanium alloy and apatite deposition on their surfaces in a simulated body fluid. Surf. Coat. Technol., 201, 8715-8722. 

Wang, X.X., Yan, W., Hayakawa, S., Tsuru, K., and Osaka, A. (2003) Apatite deposition on thermally and anodically oxidized titanium surfaces in a simulated body fluid. Biomaterials, 24 (25), 4631-4637. 

Effects of glutaraldehyde cross-link formation on apatite deposition in SBF... 

The low-grade (mill feed is approximately 3.5% to 5.5% P2O5) igneous apatite deposit at Siilinjarvi, Rn-land, on average is composed of about 65% phlogopite mica [K(Mg,Fe)3AlSi030io(bH,F)2], 19% caicite, 4%... 

Kola (USSR) crystalline apatite deposits discovered... 

The commonest concentrated igneous apatite deposits consist mainly of fluorapatite, Ca,o(P04)6F2, but isomorphous chlorapatite, CamCPO igClj, and hydroxyapatite, Caio(P04)6(OH)2, are also found in close association or in solid solution (Chapter 5.1). Apatite occurs mostly as a sedimentary deposit with an approximate composition Caio(P04)6F2, which is named Phosphorite or "phosphate rock. Collophane is a term sometimes used to describe varieties of cryptocrystalline phosphorite which are fine grained and optically isotropic. 

Workable apatite deposits occur mostly near the earth s surface in sfiata varying from a few inches to over 30 ft. About 80% of the world s phosphorite is obtained by open-cast mining methods. 

The D-vitamins are a group of fat soluble materials with high antirachitic activity. Rickets is a disease of infancy caused by faulty calcium hydroxy apatite deposition in the growing bone. It was Palm 140) in 1890 who found that the disease responded favorably to irradiation of patient s food or skin by sunlight or ultraviolet light. Mellanby 113) in 1919 first reported the presence of an antirachitic factor in cod-liver oil. This discovery encouraged research on the isolation of the active principle in fish-liver oil, but the low natural concentration of the vitamin made isolation very difficult. 

Tsuru K., Kubo M., Hayakawa S., Ohtsuki C., Osaka A. Kinetics of apatite deposition of sihca gel dependent on the inorganic ion composition of simulated body fluids. J. Ceram. Soc. Jpn. 2001b 109 412-418... 

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