Abstract
AbstractBayan Obo tailings are rich in rare earth elements (REEs), iron, and other catalytic active substances. In this study, mine tailings were calcined at different temperatures and tested for the catalytic combustion of low-concentration methane. Upon calcination at 600°C, high catalytic activity was revealed, with 50% CH4 conversion at 587°C (space velocity of 12,000 mL/g h). The physicochemical properties of catalysts were characterized using thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, hydrogen temperature-programmed reduction (H2-TPR), and X-ray photoelectron spectroscopy (XPS). Compared to the raw ore sample, the diffraction peak intensity of Fe2O3 increased post calcination, whereas that of CeCO3F decreased. A porous structure appeared after the catalyst was calcined at 600°C. Additionally, Fe, Ce, Ti, and other metal elements were more highly dispersed on the catalyst surface. H2-TPR results revealed a broadening of the reduction temperature range for the catalyst calcined at 600°C and an increase in the reduction peak. XPS analysis indicated the presence of Ce in the form of Ce3+ and Ce4+ oxidation states and the coexistence of Fe in the form of Fe2+ and Fe3+. Moreover, XPS revealed a higher surface Oads/Olatt ratio. This study provides evidence for the green reuse of Bayan Obo mine tailings in secondary resources.
Highlights
Coal mine gas is an associated gas in coal seams
Between 200°C and 400°C, the TG curve shows a small weight loss phenomenon caused by the preliminary decomposition of cerium fluorocarbon or carbonate during calcination
Sample 4 has the largest number of reduction peaks, which are at low temperatures, revealing that the redox properties of the catalyst calcined at 600°C are relatively good, improving the corresponding catalytic performance
Summary
Coal mine gas is an associated gas in coal seams. The main component of coal mine gas is methane (CH4), which is often released into the atmosphere during mining through ventilation pipes. The mine tailings still contain REEs and transition metal elements, of which REEs and iron oxides are a common raw material for catalyst preparation. Elements, such as Fe, Ce, and Mn, present in the mine trailing may display synergistic effects with other components to increase the catalytic activity in methane combustion. This study uses mine tailings as a raw material to prepare a catalyst for the catalytic combustion of low-concentration CH4. This reduces greenhouse gas emission and realizes the reuse of mine tailing resources
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
