Phosphoric Acid → Tricalcium Phosphate

Participants

Reaction Steps

Three kilograms of calcium hydroxide was dispersed in 300 kg of ion-exchanged water. To the resulting dispersion was gradually added with stirring a solution obtained by diluting 3.3 kg of a 85% by weight solution of phosphoric acid with ion-exchanged water to a total quantity of 100 kg. The pH of the resulting mixture was adjusted to 5 using a handy pH meter manufactured by HORIBA, Ltd. After forming of the salt of calcium phosphate by neutralization reaction was terminated, the resulting reaction mixture was subjected to solid-liquid separation by centrifugation (3000×g, for 5 minutes), and 4.1 kg (dry weight basis) of calcium phosphate of the solid phase portion was collected. The calcium phosphate was resuspended in ion-exchanged water, to give a slurry containing particles (average particle size: about 0.30 μm) of calcium phosphate with a solid content of 10% by weight. To 10 kg of the slurry was added and dissolved therein 0.1 kg of diglycerol monolaurate (trade name: “SUNSOFT Q-12 D”; HLB=9; manufactured by Taiyo Kagaku Co., Ltd.). The solution was heated until the temperature thereof was 45° C., and then subjected to a treatment in a homogenizer for 15 minutes. Thereafter, the temperature of the solution was further increased to 75° C., and then kept at 75° C. for 20 minutes. The resulting calcium phosphate dispersion composition (average particle size of fine metal particles: about 0.30 μm) was filled in a clear container, and stored with leaving it at rest for 1 month at normal temperatures. As a result, the composition was excellent in dispersion stability, with no occurrence of separation and precipitation of the constituents.

Provenance & Evidence