Study on the Recovery of Rubidium from Lepidolite Slag by Sulfuric Acid Leaching

The lepidolite slag from Jiangxi contains 0.51% rubidium. Utilizing lepidolite slag in cement production does not enable the efficient recovery of the rubidium it contains. This study investigates the feasibility of extracting rubidium from lepidolite slag through sulfuric acid leaching. The research method involved initially conducting single-factor experiments, followed by the application of response surface methodology to determine the optimal conditions. The optimization results revealed that the leaching rate of rubidium could reach 86.26% under the following conditions: a temperature of 85 °C, a rotational speed of 480 r/min, a sulfuric acid concentration of 3.53 mol/L, a duration of 91.64 min, and a liquid–solid ratio of 5.86. The experimental results closely matched the model’s predicted value of 86.32%. The results demonstrate the effectiveness of the response surface methodology in modeling the rubidium leaching process and provide a reference for the recycling of rubidium from lepidolite slag.