ABSTRACT
Coal and its by-product are considered a promising resource for the critical elements and rare earth elements (REEs). Due to the increasing criticality of REEs, recovering REEs from alternative resources has become essential. This research work identifies the importance of REEs and their extraction from coal, shaly coal and calcined material by leaching method. This work aims to understand the REEs recovery from raw samples (containing coal samples and shaly coal samples) and calcined material by acidic or basic solution leaching. The acid was taken in experimental leaching is Sulfuric acid (H2SO4). The base was taken here in experimental work is Sodium Hydroxide (NaOH) in leaching. Highest recovered element is Cesium which has a concentration of 73,000 ppb in collected solution after leaching, and the average concentration of REEs is 12,711 ppb after leaching. The calcined samples have given 1.5 times more recovery of REEs than normal samples in the leachate of acidic leaching. Experimental results showed that the recovery of REEs, especially LREEs, can be improved by using acidic leaching. It also depicts that the most effective recovery of REEs was from calcined coal material by acidic leaching.
Acknowledgments
The authors would like to thank the Department of Mining Engineering, Indian Institute of Technology (BHU), Varanasi, India, and Geochemistry Lab, Birbal Sahni Institute of Palaeosciences, Lucknow, India, for providing necessary facilities in this study. The authors would like to thank Mr. Nikhilesh Singh, Department of Civil Engineering, Indian Institute of Technology (BHU), Varanasi, India, for his kind support in framing this manuscript.
Disclosure Statement
No potential conflict of interest was reported by the author(s).