A study of the floatability and leaching behavior of eucryptite and eucryptite-containing slag

Abstract

With the application of pyrometallurgical technology in the recycling of spent lithium-ion batteries, eucryptite has been found as an artificial mineral in various lithium-bearing slags. Unlike spodumene, eucryptite has a higher lithium content and does not require high temperature roasting prior to leaching. Therefore, the study of the floatability and leaching behavior of eucryptite and eucryptite-containing slags is crucial for optimizing the pyrometallurgical recycling route of spent lithium-ion batteries. In this study, fundamental research is carried out on micro-flotation, surface property analysis and leaching behaviour of the natural eucryptite minerals. In micro-flotation tests, eucryptite showed a significant difference in floatability when using sodium oleate and dodecylamine. The disparity in yield between different minerals when employing the same collector serves as the foundation for selective flotation separation. A greater disparity indicates a higher expected efficiency in separation. In the dodecylamine system, eucryptite showed a higher yield compared to the gangue mineral gehlenite, with a maximum yield difference of approximately 35 %. In addition, flotation tests on eucryptite-containing slag demonstrate the potential for separating eucryptite, γ-lithium aluminate and the gangue mineral gehlenite from slag by multi-stage flotation. In the leaching test, the leaching efficiency of lithium in the natural eucryptite mineral approaches 97 % and in the slag approaches 100 %.