Abstract:The tailings (raw ore used in this work) produced from a lithium flotation plant in Liaoning province contains 0.43% Li2O, mainly in the forms of lepidolite (2.20%) and spodumene (3.84%). Abundant ferromagnetic minerals as impurities were found in the ore, and they would adversely affect the flotation enrichment of lithium minerals from the ore. Such ore can be defined as a difficultly concentrated ore with low lithium grade. Based on the raw ore properties and preliminary separation tests results, a technology route of "magnetic separation pre-treatment for removing ferromagnetic impurities, and then an open-closed circuit stepwise flotation process for concentrating lithium minerals from the magnetic separation tailings" was proposed for treating the ore. During flotation process, an amphoteric collector AP01 and a multiple fatty acid collector CA01 were respectively employed to float lepidolite with an open-circuit process, and spodumene with a closed-circuit process. Under optimized conditions, a lepidolite concentrate with 9.46% weight, 1.21% Li2O grade and 26.62% Li2O recovery, and a spodumene concentrate assaying 1.92% Li2O grade with 10.04% weight and 44.83% lithium recovery were produced by the batch-scale tests. The Li2O grade and recovery of two concentrates mixture are 1.58% and 71.65%, respectively, which reached the marketable grade of lithium resources. The analysis results of concentrates indicated that the AP01 and CA01 collectors exhibited excellent flotation selectivities for lepidolite and spodumene, respectively, and their cooperation can effectively collect the hardly floated lepidolite with ultrafine particle sizes. This work may provide valuable references for the comprehensive utilization of the low grade lithium resource.