NGHIÊN CỨU QUÁ TRÌNH HÒA TÁCH NHẰM THU NHẬN U, Th VÀ ĐẤT HIẾM TỪ BÙN HYDROXIT CỦA QUÁ TRÌNH THUỶ LUYỆN MONAZIT

Tóm tắt

STUDY ON THE LEACHING PROCESS FOR RECOVERING URANIUM, THORIUM, AND RARE EARTH ELEMENTS FROM THE HYDROXIDE RESIDUE OF ALKALINE MONAZITE HYDROMETALLURGY

The hydroxide residue obtained from the selective leaching stage at pH = 4 during the alkaline hydrometallurgical processing of monazite was further leached using various acidic and carbonate agents. The effects of pH, temperature, leaching time, and reagent concentration on the simultaneous and selective dissolution efficiencies of rare earth elements, thorium, and uranium were systematically investigated.The results indicated that, for the acid leaching process, a final pH range of 0.35–0.5 was suitable for dissolving these target elements from the initial hydroxide residue. In contrast, leaching with carbonate agents yielded lower overall dissolution efficiencies than the acid route; however, U and Th could be selectively separated from the rare earth elements fraction. The leach residue obtained after carbonate treatment, which mainly contained rare earth elements, was recycled to enhance the overall recovery efficiency.