Phosphate → Tricalcium Phosphate

Participants

Reaction Steps

A solution of 218 g of disodium Na2HPO4.12H2O) in 1.2 liters of distilled water and a solution of 70 g of Ca(NO3)2.4H2O in 0.5 liters of distilled water were prepared. The calcium solution was quickly poured into the phosphate solution at room temperature with stirring. Precipitation was immediate and substantially complete. The precipitate was adjusted to pH 6.4 by the addition of sodium hydroxide solution in order to avoid the formation of acidic calcium phosphates. The precipitate was aged at room temperature for 5 minutes prior to filtration. The precipitate was then filtered through a Buchner filter (with a total surface about 0.1 m2), and was washed by about 3 liters of distilled water. A gel cake of low crystallinity calcium phosphate obtained on the filter paper.

Provenance & Evidence