Tricalcium orthophosphate

Anhydrous dibasic calcium phosphate and calcium triphosphate can also be used for direct compression. The latter is actually a mixture of calcium phosphates including tricalcium orthophosphate [Ca3(P04)2] and hydroxyapatite [Ca5(0H)(P04)3]. The preparation and properties of calcium phosphates have been reviewed by Carstensen and Ertell, and their tabletting properties have been studied by Bryan and McAllister. 

Calcium orthophosphate E341 hydroxylapatite phosphoric acid calcium salt (2 3) precipitated calcium phosphate tertiary calcium phosphate Tri-Cafos tricalcium diorthophosphate tricalcium orthophosphate tricalcium phosphate TRI-CAL WG-, TRI-TAB. 

The preparation of pure tricalcium orthophosphate by an alternate route was already described 200 years ago in an encyclopaedia as follows ... 

Tribasic calcium phosphate, Ca3(P04)2, may be called calcium orthophosphate, tricalcium orthophosphate, tertiary calcium orthophosphate, or tricalcium phosphate. Unlike the other two forms, the tribasic form contains no hydrogen atoms. 

Synonyms Calcium orthophosphate Calcium phosphate tertiary Phosphoric acid, calcium salt (2 3) Precipitated calcium phosphate TCP Tertiary calcium phosphate Tribasic calcium phosphate Tricalcium bis (orthophosphate) Tricalcium orthophosphate Tricalcium phosphate... 

Tricalcium orthophosphate. See Calcium Specialty Chemicals Source Book-Third Edition... 

At equilibrium, the least soluble substance in a system that can form will precipitate. Much phosphate contained in sea water is precipitated as tricalcium orthophosphate or hydroxyl apatite, Caio(P04)6(OH)2, and fluorapatite, Caio(P04)6(F)2. Oceans floors are covered with these deposits and are referred to as marine pellets. There are many ways in which this problem may be approached, but it is obvious that if phosphates are to be leached from igneous rocks, large boulders will leach very slowly. Smaller particles of rock caused by grinding, weathering, and aging solubilize more rapidly than larger particles. As a first approximation, rates of solubilization are proportional to fresh surfaces of solubilized rocks. 

Elemental phosphorus is made by heating a mixture of phosphate rock, Ca4(P04)2(0H,F)2 or Ca3(P04)2 Ca(0H,F)2, to write it as the solid solution of tricalcium orthophosphate and calcium hydroxide or fluoride, or both, with quartz and coke. See Chapter 3. Elemental phosphorus is burned to phosphorus pentoxide and the pentoxide is allowed to react with water to form very pure phosphoric acid. 

Tricalclutn bis (orthophosphate) Tricalcium orthophosphate Tricalcium phosphate. See Calcium phosphate tribasic Tricaprin... 

Phosphate is sometimes present in MU water sources (say, 1-2 ppm or more) usually as a result of field and factory run-off or from the deliberate addition as a city water threshold agent to prevent corrosion and deposition in the mains. The steady growth in the reuse of secondary water sources such as municipal and industrial waste waters means that phosphate is increasingly likely to be present in MU. If the phosphate remains undetected, it likely will scale and foul FW lines by forming amorphous calcium orthophosphate [tricalcium phosphate Caj(P04)2] sludge before it reaches the boiler section. 

Synonyms calcium orthophosphate calcium phosphate tricalcium phosphate tertiary calcium phosphate precipitated calcium phosphate bone ash (technical product). 

Calcium phosphate will ordinarily precipitate at concentrations typically exceeding 5 ppm PO4 or less, forming amorphous calcium orthophosphate (tricalcium phosphate) sludge, Ca3(P04>2, in the bulk water and crystalline hydroxyapatite, Caio(OH)2(P04)2, at heat-transfer surfaces. 

In many hard-working cooling systems where orthophosphate is present without adequate stabilizing dispersant, tricalcium phosphate initially forms, often with variable water of crystallization and together with other calcium phosphate salts. These salts gradually change, under high alkalinity and temperature conditions, into the even more insoluble hydroxyapatite. 

Calcium (titanium, zirconium) orthophosphate ceramics show solubility in SBF at least one order of magnitude lower than that of other calcium orthophosphates including hydroxyapatite and, in particular P-tricalcium phosphate (TCP) and tetracalcium phosphate (TTCP) (Figure 4.20). 

Figure 7.2c represents a situation of advanced thermal decomposition during which P-tricalcium phosphate (fl-TCP, denoted by 3 ) and TTCP (denoted by 4 ) have been formed (step 3 of Table 6.7). Finally, in Figure 7.2d an even stronger decomposition of either orthophosphate towards CaO (denoted by 1 ) has occurred (step 4 of Table 6.7) owing to a shorter spray distance (240 mm) and substrate preheating. 

Information on the degree of disorder introduced by thermal treatment of hydroxyapatite during plasma spraying could be obtained by NMR spectroscopy. The positions and shift of 1H-MAS and 31P-MAS NMR peaks are indicative of the environment of the P043- tetrahedra in calcium orthophosphates and allow distinguishing between dehydroxylation (oxyhydroxyapatite) and decomposition (tricalcium phosphate, tetracalcium phosphate) products of hydroxyapatite. 

Bonarka Calcigenol simple Calcium orthophosphate Calcium phosphate Calcium phosphate (3 2) Calcium phosphate (Ca3(P04)2) Calcium phosphate, tribasic Calcium tertiary phosphate Caswell No. 148 CCRIS 3668 EINECS 231-840-8 EPA Pesticide Chemical Code 076401 FEMA No. 3081 HSDB 879 Natural whitlxkite Phosphoric xid, calcium salt (2 3) Phosphoric acid calcium(2+) salt (2 3) Synthos Tertiary calcium phosphate Tribxic calcium phosphate Tricalcium diphosphate Tricalcium... 

This shows that the system in equilibrium with the less soluble solid can contain four orders of magnitude less orthophosphate than the water in equilibrium with jS-tricalcium phosphate. 

Apatitic TCP (ap>-TCP) Ca9(HP04)(P04)5(0H) is a calcium orthophosphate which, during thermal treatment at temperature higher than 750°C, transforms onto P-tricalcium phosphate Ca3(P04)2. 

Destainville A., Champion E., Bernache-Assollante D., et al. (2003). Synthesis, characterization and thermal behaviour of apatite tricalcium phosphate // Materials Chemistry and Physics, No. 80, pp. 269 - 277 Dorozhkin S.V. (2009). Calcium Orthophosphates in Nature, Biology and Medicine. Materials, 2 pp. 399-498... 

Tributyrinase Tributyrin esterase. See Lipase Tributyroin. See Tributyrin Trie. See Trichloroethylene TRi-CAL WG. See Calcium phosphate tribasic Tricalcium aluminate. See Calcium aluminate Tricalcium bis (orthophosphate). See Calcium phosphate tribasic... 

Calcium phosphate (1869) (calcium orthophosphate, tricalcium phosphate, tri-calcic phosphate, and tertiary calcium phosphate) n. Ca3(P04)2. A stabilizer. 

Figure 10.18 Solubilities of several Ca-Ti-Zr orthophosphates (C-C) as well as hydroxyapatite (A) and a-tricalcium phosphate (B) in protein-free simulated body fluid (pf-SBF) at...

Figure 10.28 Solubility isotherms of calcium orthophosphates at 25 °C. HAp hydroxyapatite DCPD brushite DCPA monetite P-TCP P-tricalcium phosphate OCP octacalcium phosphate TTCP tetracalcium phosphate (De Groot et ai, 1990).

The higher the chlorinity of the water, the more it requires a good dosage of corrosion inhibitors. Traditional glassy metaphosphates lose much of their effectiveness because they revert in time to orthophosphates. There is also an attendant possible danger of precipitation of tricalcium phosphate. This is a function of pH, calcium, orthophosphate, and solids concentration of the water. Silicates have also been used in water systems, but tend to have an adverse effect on heat transfer because of the deposition of relatively heavy films. 

There are such simplistic mechanisms as lightning striking an outcropping of calcium orthophosphate that may have contained some sand or other form of Si02 embedded in the outcropping. To make the equation simple, we will write the apatite as tricalcium phosphate and the metasilicates in their simplest form. 

It should be noted that calcium polyphosphates are often called metaphosphates in the literature and patents, if they have M2O-P2O5 ratios near unity. Throughout this work, the word metaphosphate will be reserved for ring phosphates while chain phosphates will be named polyphosphates. In most modern usage the prefix poly- has unfortunately been dropped from a name. Calcium tripolyphosphate, Ca5(P30io)2, is named calcium triphosphate, which can easily be confused with tricalcium phosphate, Ca3(P04)2, an orthophosphate, by those who only occasionally engage in phosphate chemistry. In this work polyphosphates shall be named polyphosphates, unless reference is made to work where polyphosphates are named without the prefix. Here, they will be named as in the cited literature. 

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