The seeded growth of calcium phosphates. The effect of solid/solution ratio in controlling the nature of the growth phase

Barone, J. P.; Nancollas, G.H.

doi:10.1016/0021-9797(77)90093-5

Cited by 32 publications

(11 citation statements)

References 18 publications

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“…Recall that the pellet reactor ef ciency depends not only on pH but also on the hydrodynamic conditions (Montastruc et al, 2002a). Moreover, the conversion rate depends on calcium and phosphate ion concentrations, as well as on supersaturation, ionic strength, temperature, ion types, pH but also on time (solid-solid transformation), as noted in the literature (Baronne and Nancollas, 1977;Van Kemenade and de Bruyn, 1987;Boskey and Posner, 1973).…”

Section: Process Descriptionmentioning

confidence: 91%

A General Framework for Pellet Reactor Modelling: Application to P-Recovery

Montastruc

Azzaro‐Pantel

Biscans

et al. 2003

Chemical Engineering Research and Design

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E mphasis in recent years has been focused on improving processes which lead to enhanced phosphate recovery. This paper studies the precipitation features of calcium phosphate in a uidized bed reactor in a concentration range between 4 and 50 mg l 1 and establishes the conditions for optimum phosphate removal ef ciency. For this purpose, two models are coupled for predicting the pellet reactor ef ciency. First, a thermodynamical model is used for predicting calcium phosphate precipitation vs. initial conditions (pH, [P], [Ca], temperature). The second one is a reactor network model. Its parameters are identi ed by an optimization procedure based on simulated annealing and quadratic programming. The ef ciency is computed by coupling a simple agglomeration model with a combination of elementary systems representing basic ideal ow patterns (perfect mixed ow, plug ow, etc.). More precisely, the superstructure represents the hydrodynamical conditions in the uidized bed. The observed results show that a simple combination of ideal ow patterns is involved in pellet reactor modelling, which seems interesting for a future control. The experimental prototype used for validation purpose is rst described. Then, the thermochemical model is presented for calcium phosphate precipitation. The third part is devoted to the reactor networkoriented model. The approach presented is nally validated with experimental runs.

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Section: Process Descriptionmentioning

confidence: 91%

A General Framework for Pellet Reactor Modelling: Application to P-Recovery

Montastruc

Azzaro‐Pantel

Biscans

et al. 2003

Chemical Engineering Research and Design

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“…The formation of nanocrystalline calcium phosphate in microemulsion systems has been described as a fairly complicated process and is known to be dependent on several parameters such as calcium and phosphate ion concentration, ionic strength, pH, temperature and nature and concentration of surfactants [23][24][25]. Previous works mainly emphasized upon controlling the stoichiometry of reactants, whereas with the development of nanotechnologies, considerable efforts are now focused on controlling the morphology and size because studies have shown that many chemical capabilities of calcium phosphate mainly depend on their morphology and size [26].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of nanocrystalline calcium phosphate in microemulsion—effect of nature of surfactants

Singh

Bhardwaj

Singh

et al. 2008

Journal of Colloid and Interface Science

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“…The uptake of fluoride into HAP and the precipitation of fluorapatite (Ca 10 (PO 4 ) 6 F 2 or FAP) can protect teeth from caries, but at higher exposure, may lead to discoloration of teeth or even crippling bone weakness [2]. Medical and dental applications have motivated studies of HAP and FAP precipitated under highly-controlled and non-physiological conditions (e.g., hydrothermal synthesis [3,4] or aerosol deposition onto titanium [5] or after calcination [6,7]) complementing earlier studies on the precipitation of a variety of calcium phosphate solids [8][9][10][11][12][13][14]. In most studies, HAP and FAP (in the presence of dissolved fluoride, F) have been the thermodynamically-favored phases, but the formation of other calcium phosphate solids, particularly as intermediates, has also been reported depending on reaction time, solution conditions including the degree of super-saturation, initial calcium-to-phosphate (Ca/P) ratios, pH and ionic strength, temperature and surface area of HAP added as a seed template.…”

Section: Introductionmentioning

confidence: 99%

Strontium hydroxyapatite and strontium carbonate as templates for the precipitation of calcium-phosphates in the absence and presence of fluoride

Sternitzke

Janousch

Heeb

et al. 2014

Journal of Crystal Growth

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The heterogeneous precipitation of calcium phosphates on calcium hydroxyapariLe (Ca-10(PO4)(4)OH)(2) or HAP) in the presence arid absence of fluoride is important in the formation of bone and teeth, protection against tooth decay, dental and skeletal fluorosis and defluoridaLion of drinking wafer. Strontium hyclroxyapariLe (Sr-10(PO4)(6)(OH)(2) or SrHAP) and strontium carbonate (SrCO3) were used as calcium free seed templates in precipitation experiments conducted with varying initial calcium-Lophosphate (Ca/P) or calcium-Lo-phosphaLe-Lo-fluoride (Ca/P/F) ratios. Suspensions of SrHAP or SrCO3 seed templates (which were calcium limited for both templates and phosphate limited in the case of SECO3) were reacted at pH 7.3 (25 degrees C) over 3 days. The resulting solids were examined with Scanning Transmission Electron Microscopy (STEM), X-ray Diffraction (XRD), Fourier Transform Infrared (MR), and X-ray Photoelectron Spectroscopy (XPS), X-ray Absorption Near Edge Structure (XANES), and Extended X-ray Absorption Fine Structure spectroscopy (EXAFS). Calcium apatite was the predominant phase identified by all techniques independent of the added Ca/P ratios and of the presence of fluoride. It was not possible to make an unambiguous distinction between HAP and fluorapatite (Ca-10(PO4)(6)F-2, FAP). The apatite was calcium-deficient and probably contained some strontium

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The seeded growth of calcium phosphates. The effect of solid/solution ratio in controlling the nature of the growth phase

Cited by 32 publications

References 18 publications

A General Framework for Pellet Reactor Modelling: Application to P-Recovery

A General Framework for Pellet Reactor Modelling: Application to P-Recovery

Synthesis of nanocrystalline calcium phosphate in microemulsion—effect of nature of surfactants

Strontium hydroxyapatite and strontium carbonate as templates for the precipitation of calcium-phosphates in the absence and presence of fluoride

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