Abstract

Waste hydrogenation catalysts are usually listed as hazardous wastes due to their high heavy metal contents. These heavy metals such as molybdenum, vanadium, nickel, and cobalt will affect environment, human health, and wildlife. Moreover, the waste hydrogenation catalysts represent a valuable secondary resource, containing a significant quantity of valuable metals, recycling them will bring economic benefits, alleviate the need for mining investment, and reduce the environmental impact of mining. However, the current process presents many environmental and economic challenges, including sulfur dioxide pollution, more reagent consumption, and complicated operation. As a result, a new method is necessary to alleviate these drawbacks. In this work, a novel calcification roasting-acid leaching method was proposed to recycle the waste catalyst. The calcification roasting process was studied focally and systematically, including thermodynamics, reaction mechanisms, and phase transformation. The behaviors of Mo, V, Ni, and Al in the leaching process were studied, and influence factors, including roasting temperature, calcium additives feeding, acid concentration, leaching temperature, leaching time, liquid-solid ratio, and particle size were explored. Under the optimal conditions, the leaching efficiency for Mo and V reached 98.02 % and 97.28 % respectively. In contrast, there is no Ni and Al in the post-leaching solution, demonstrating excellent leaching ability for Mo and V, and robust leaching selectivity. Moreover, this novel method shows environmentally friendly properties, as it reduces SO2 generation. From the perspectives of resources, environment, and economy, this novel approach shows a competitive advantage and bright prospect.

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

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.