Simultaneous extraction of uranium and niobium from a low-grade natural betafite ore

Abstract

This work efficiently investigated the simultaneous extraction of uranium (U) and niobium (Nb) from a low-grade natural betafite ore by using novel technique, namely, sulfatizing roasting coupled to sulfuric acid leaching process. First, the sulfatizing roasting was adopted to alert the properties of the raw ore, aiming to destroy the crystal structure of the ores and convert the valuable elements to soluble sulfate compounds. Moreover, the influences of the parameters affecting the sulfatizing roasting including roasting temperature, amount of sulfuric acid, and roasting time were studied. The results indicated that the extraction of U and Nb from the ores with sulfatizing roasting was an order of magnitude higher than the extraction of U and Nb from the ores without roasting under the same test conditions. Then, the effects of amount of sulfuric acid concentration, liquid–solid ratio, leaching temperature, and leaching time on U and Nb recoveries were systematically investigated. To verify the process parameters of extracting U and Nb for the novel technique, three validating tests were conducted, and the results showed that over 95% of U and 85% of Nb were leached out under the optimal conditions. The novel technique was proven as advantageous since it conspicuously improved the leaching rates of U and Nb and promoted the refractory natural betafite ores to become an economic source for uranium.

Keywords

• uranium
• niobium
• betafite
• leaching
• sulfatizing roasting