A strategy for treatment of low-grade ore: Efficient separation and purification of iron

The gradual depletion of mineral resources has led to the emergence of a new engineering challenge in the field of mineral processing: the effective treatment of low-grade ores. In this study, the low-grade titanium ore leaching solution was employed as the raw material. The extraction ability of a series of hydroxyl extractants for the most common metal iron in minerals was investigated. As a result, a new high-quality processing system for low-grade ore with branched-chain octanol as the core component was constructed. In the treatment of mineral leaching solution, branched-chain octanol has high selectivity and large capacity (111.7 g/L) for iron. It was capable of efficiently removing a significant quantity of iron ions in low-grade ores that were not anticipated to be present. By employing quantum chemical (QC) methodologies, the mechanism for the high selectivity of branched-chain octanol for Fe(Ⅲ) has been elucidated by analyzing the frontier molecular orbital (FMO) energy of acid salts of common metals in minerals. Combined with spectral analysis and slope method, the structure of the extracted complex was confirmed to be [n-R₈-OH]₂·H·FeCl₄. On the basis of system optimization, a three-stage countercurrent extraction and three-stage countercurrent stripping was employed to remove all the Fe(Ⅲ) in the mineral leaching solution. And after detecting, the purity of the obtained Fe(III) solution was greater than 99.5 %. In the treatment of low-grade minerals, especially those containing key metals, the branched-chain octanol extraction system demonstrates high selectivity and reliability, which is a effective means to improve the quality of mineral leaching solution.