Study on alkali liquor roasting and sulphuric acid leaching of bayan obo rare earth concentrate

Abstract

Take the roasted ore after the alkali liquor roasting and decomposition of Bayan Obo rare earth concentrate as the raw material, and use the sulphuric acid leaching to extract the elements including rare earth, thorium, tetravalent cerium, etc. The influence on the leaching of rare earth, thorium, tetravalent cerium made by the leaching conditions including mineral acid ratio, initial acidity, leaching temperature, and leaching time is researched. The result shows: when the mineral acid mass ratio is 1:1,1, the initial acid concentration is 6 mol/L, the reaction temperature is 90 °C, and the reaction time is 120 min, the gross leaching rate of rare earth is greater than 95 %, and the leaching rate of tetravalent cerium and thorium is greater than 97 %