Production of monetite

Abstract

Abstract PURPOSE:To produce monetite having prescribed crystal size in high efficiency without causing environmental pollution, by adding powder of CaO, Ca(OH)2 or CaCO3 to a concentrated aqueous solution o phosphoric acid and reacting at a prescribed temperature under highly acidic condition. CONSTITUTION:One or more kinds of powdery materials selected from CaO, Ca(OH)2 and CaCO3 and having particle diameter of <=100mum is slowly added to a concentrated aqueous solution of phosphoric acid having a concentration of >=10%, the pH of the mixture is adjusted to a strong acid range (e.g. <=3.5) and the components are made to react at a temperature within a prescribed range for a definite period to effect the precipitation of the reaction product from the solution. The crystal size of the product can be controlled to a prescribed level by this process (e.g. fine-crystalline monetite at <=40 deg.C and crystalline monetite at >=40 deg.C). The precipitate is filtered, washed and dried to obtain a high-quality monetite having prescribed size in high yield.

Inventors

• 👤 Hideki Aoki
• 👤 Osamu Fujii
• 👤 Atsuo Ito

Bibliographic Details