Sequential separation and selective extraction of uranium and thorium from monazite sulfate leach liquor using dipropylamine extractant

•A novel method for sequential separation of U and Th from REEs has been devised.•Dipropylamine was used for the first time to extract U and Th from Monazite.•Selective Th separation (98%) was obtained at pH 1 using Dipropylamine.•Then, 97% U was extracted from the remained monazite sulfate solution at pH 3.•It was used for technological application to produce pure U and Th from monazite. Monazite mineral is the main source of uranium and thorium, which are mainly associated with rare earth elements (REEs). So, their separation is the crucial task to satisfy their application for nuclear fuel. Dipropylamine was used for the first time in the selective extraction and separation of uranium and thorium from Monazite sulfate leach liquor. The extraction of thorium (98%) was achieved using dipropylamine in kerosene at pH 1; it was followed by selective extraction of uranium (97%) by Dipropylamine at pH 3. The thermodynamic analysis demonstrated that uranium (VI) and thorium (IV) extraction by dipropylamine is an exothermic process. From the stripped liquor (1 M H2SO4), Th and U were precipitated as oxalate and peroxide, respectively, for technological application. Thus, marketable pure thorium and uranium products were prepared in addition to rare earth concentrate.