| 摘要 |
The invention relates to a process for preparing alkaline earth silicates applied in medical dentistry and to an installation for applying the process. The claimed process consists in the chemical reaction at temperatures of 20...50°C of magnesium, calcium or barium salt or hydrosoluble, partially soluble or insoluble hydroxide, in phase emulsion made with a jet of carrier gas or liquid in uniflow, at a pressure of 1.2...3 bar, with lithium, sodium or potassium alkaline silicate, the reactant solution having concentrations of 1...20% by weight, in a reaction area with internal partial recirculation of the emulsion, the resulting silicate hydrogel is separated by ultra-centrifuging, possibly filtered under vacuum, followed by repeated washing with distilled water, the paste resulting from separation being conditioned by drying, wherefrom there results a solid powder having a grain size of 100...1000 nm. The claimed installation comprises a chemical reactor () provided with two static mixers (), a connection () for injecting the carrier gas, two connections () for injecting the aqueous solutions, two dosing vessels (), two heat exchangers () for preheating the aqueous solution, a vertical cylindrical vessel () for separating the emulsion hydrogel and a column () for separating the gas/liquid drops and exhausting the residual gas. |
