Study on Roasting and Non-acid Leaching Test of a Low Grade Clay Type Lithium Ores
This study investigates a novel low-temperature roasting and non-acid leaching lithium extraction process using a new roasting aid,ASH,for an extremely low-grade clay lithium ore in Yunnan,China,with a lithium content of 0.147%.The reaction mechanism was elucidated through X-ray Diffraction(XRD),Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy(SEM-EDS),and other analysis methods.Experimental results demonstrated that under the conditions of a sample to ASH mass ratio of 1∶0.3,roasting temperature at 400℃,roasting time of 1.0 hour,deionized water as the leaching agent,leaching time of 2 hours,leaching temperature of 70℃,and liquid-solid ratio of 5 mL/g,the lithium leaching rate reached 83.81%.Mechanism analysis indicated that while the main mineral phases in the sample remained unchanged before and after roasting-leaching,the intensity of diffraction peaks decreased.Post roasting-leaching,the sample surface exhibited u-niform distribution of cracks and voids,along with decreased contents of Al,Si,Fe and Ti.This suggests a reaction between ASH and minerals,disrupting the mineral surface structure and generating soluble Li-ASH leachate.Compared to traditional roasting-leaching processes,this study's lithium extraction process features lower roasting temperatures and acid-free leaching,reducing production energy consumption,simplifying the process flow,and offering significant insights for the green and effi-cient development and utilization of similar low-grade clay lithium ores.
clay type lithium oreroasting agent ASHlow temperature roastingnon-acid leaching
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