PREPARATION AND PRODUCTION APPARATUS FOR GOETHITE PARTICLE POWDER OF NEEDLE-LIKE CRYSTAL

摘要

PURPOSE:To obtain the titled crystal having narrow distributions of particle length and axial ratio, by preventing entanglement of an oxidizing gas at the top of reaction solution, bringing only small bubbles of the oxidizing gas introduced into the reaction solution into contact with suspenson of Fe(OH)2. CONSTITUTION:In a method to prepare goethite particles of needle-like crystal by neutralizing an aqueous solution of ferrous salt (e.g., aqueous solution of FeCl2, etc.) with an alkali aqueous solution to give suspension of Fe(OH)2, bringing the suspension into contact with an oxidizing gas (e.g., air, etc.) to oxidize it, for example, entanglement of the oxidizing gas at the top of the reaction solution is prevented by setting the disc baffle plate 4, and, for example, small bubbles are dispersed into the reaction solution by stirring air, etc. introduced from the feed inlet 3 for the oxidizing gas by the agitating blade 5, so that they are brought into contact with the reaction solution. Goethite particle powder of needle-like crystal having narrow distribution of particle length, axial ratio, and even shape can be prepared by equalizing the composition of the reaction solution.