Study on the characteristics of rubidium and cesium carrier minerals in the beneficiation process of lithium-bearing clay

• Lepidolite and K-feldspar were identified as the primary Rb/Cs carriers. • Low lepidolite liberation and significant fine-grain losses were revealed. • High K-feldspar content in flotation tailing demonstrated recovery potential. Rubidium (Rb) and cesium (Cs), as rare alkali metals, play a critical role in high-tech industries. However, their efficient extraction from associated mineral resources is challenging, especially in lithium-bearing clays due to fine-grained dissemination and isomorphic association. This study investigated lithium-bearing clay from Yichun, Jiangxi Province, using single-mineral analysis, beneficiation process flow sampling, and MapsMin automated mineral analysis to explore the characteristics of Rb and Cs carrier minerals. It was found that lepidolite and K-feldspar were the main carriers of Rb and Cs. The liberation degree of lepidolite in the flotation feed was relatively low at 66.32%. Desliming overflow lost 16.51% of lepidolite, with 92.48% of it being smaller than 19 μm, while flotation tailing lost 18.03% of lepidolite, with the unrecovered grain sizes concentrated below 19 μm and above 300 μm. The concentrator did not recover K-feldspar, and 83.54% of K-feldspar remained in the flotation tailing after lepidolite separation. Proposed optimization directions for rubidium and cesium recovery include enhancing grinding liberation, minimizing fine-grain losses, and recovering K-feldspar from tailings. Comprehensive mineralogical analysis provides a basis for designing efficient rubidium and cesium recovery processes.