METHOD TO REDUCE BORON CONTENT OF OXIDE OF RARE EARTH ELEMENT INCLUDING BORON

摘要

PROBLEM TO BE SOLVED: To provide a method to simply reduce a boron content of oxides of rare earth elements including boron.SOLUTION: Oxides of rare earth elements including boron are subjected to heat treatment with alkali metal carbonates and/or oxides. The heat treatment is preferably performed at 1150°C or more.