Hydration in the System Ca2SiO4–Ca3(PO4)2 at 90°C |
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Authors: | Mary W. Barnes Maria Klimkiewicz Paul W. Brown |
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Affiliation: | Materials Research Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802 |
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Abstract: | Compositions along the Ca2SiO4–Ca3(PO4)2 join were hydrated at 90°C. Mixtures containing 15, 38, 50, 80, and 100 mol% Ca3(PO4)2 were fired at 1500°C, forming nagelschmidtite + a 1-CaSiO4, A -phase and silicocarnotite and a -Ca3(PO4)2, respectively. Hydration of these produces hydroxylapatite regardless of composition. Calcium silicate hydrate gel is produced when Ca2SiO4≠ 0 and portlandite when Ca2SiO4 is >50%. Relative hydration reactivities are a -Ca3(PO4)2 > nagelschmidtite > α 1-Ca2SiO4 > A -phase > silicocarnotite. Hydration in the presence of silica or lime influences the amount of portlandite produced. Hydration in NaOH solution produces 14-A tobermorite rather than calcium silicate hydrate gel. |
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Keywords: | hydration calcium silicate calcium phosphate high temperature hydroxylapatite |
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