Production of zinc oxide coated powders

摘要

This disclosure concerns the production of ZnO (zinc oxide) coated particles for use in rubber as a substitute for bulk ZnO particles. Compared to bulk oxide, oxide coated particles offer the advantage of a higher specific surface per mass unit of ZnO. This implies both ecological and economical benefits. An enhanced process is presented for the synthesis of aggregate particles, comprising a core of CaCO3, which is at least partially coated with ZnO, comprising the steps of: heating a metallic Zn bath, thereby evaporating Zn and forming a Zn-vapor atmosphere; injecting CaCO3 particles as core compound in the Zn-vapor atmosphere; injecting air in the Zn-vapor atmosphere in an amount in excess of the stoechiometric need for the oxidation of the Zn vapor to ZnO. This process is clean and sustainable, producing no unnecessary phases.

主权项

1. A process for the synthesis of aggregate particles, each particle comprising a core of CaCO3, which is at least partially coated with ZnO, comprising:
heating a metallic Zn bath, thereby evaporating Zn and forming a Zn-vapor atmosphere; injecting air into the Zn-vapor atmosphere in order to oxidize Zn vapor to ZnO, wherein the amount of air being injected is at least 700% of the stoichiometric needs for the oxidation of the Zn vapor to ZnO; and injecting CaCO3 particles as core compound in the Zn-vapor atmosphere.