PRODUCTION OF HEMATITE PARTICLE POWDER

摘要

PURPOSE:To obtain hematite particle powder having uniform particle size and each independent particle by short-time reaction, by subjecting an acidic suspension containing a given concentration of beta-FeOOH particles having a particular specific surface area to hydrothermal treatment. CONSTITUTION:An acidic suspension containing <0.1mol/l beta-FeOOH particle having >=150m<2>/g is subjected to hydrothermal treatment at 100-130 deg.C. Produc tion of hematite particles having uniform particle size is difficult and formation reaction of the hematite particles requires a long time when the beta-FeOOH particle powder has <150m<2>/g specific surface area. The beta-FeOOH particle powder having >=150m<2>/g specific surface area is obtained by hydrolyzing an aqueous solution of ferric chloride by heat treatment at 70-90 deg.C. The hematite particles are not formed when the acidic suspension has >=0.1mol/l concentra tion.