An effective method for directly extracting lithium from a-spodumene by activated roasting and sulfuric acid leaching

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) 2023, 122(0), , pp.540-550
• Main Authors: Yuqing Zhang, Baozhong Ma, Yingwei Lv, Chengyan Wang, Yongqiang Chen
• Format: Article
• Language: English
• Subjects: 화학공학
• ISSN: 1226-086X; 1876-794X

The global trend toward electrification has encouraged lithium’s market position to grow prominently. Spodumene is the focus of lithium extraction owing to its abundant lithium resources. In this study, anovel lithium extraction method was proposed for a-spodumene by combining activated roasting andsulfuric acid leaching. First, the thermodynamics of the roasting process demonstrated that aspodumenewas converted into b-spodumene, which reacted with CaO to produce acid-solubleLiAlSiO4 and CaSiO3 concurrently. The addition of CaO reduced the melting temperature, which promotedthe structural transformation of b-spodumene and further acid leaching. Then, the influences of variousfactors on lithium extraction were investigated by a single-factor test. A lithium leaching yield of 96.18%was obtained under optimum conditions: 20% CaO, roasting temperature of 1200 C, holding time of1.5 h, H2SO4 concentration of 120 g/L, liquid–solid ratio of 7:1 mL/g, leaching temperature of 80 Cand leaching time of 1.5 h. Finally, Li entered into leach liquor by the action of sulfuric acid, and the maincomponents of the leach residue were silicate and calcium sulfate. Compared to the conventional acidapproach, this method has a higher lithium recovery and lower energy and acid consumption (decreaseby approximately 0.42 kg/ kg). KCI Citation Count: 0