Clean recycling of Zn-bearing slags by a plasma fuming process

2a51c cheng 2024 16.9

Zhongfu Cheng and colleagues from the Department of Materials Engineering, KU Leuven has published a new article on the clean recycling of Zn-bearing slags using a plasma fuming process. The article is published the JUne issue of the Chemical Engineering Journal.

The present study focuses on developing a plasma-intensified slag-fuming process for recycling Zn-bearing slags. A pilot trial was conducted in a plasma-fuming furnace, and thermodynamic calculations were performed to identify optimal operating parameters. The desired reaction atmosphere was achieved by controlling the C3H8-to-air ratio at 0.050 and 0.071 for the feeding and reducing stages, respectively. Zn fuming was predominantly achieved during the reducing stage, while Pb fuming was mainly realized in the feeding stage. After slag fuming, valuable elements (Zn, Pb, In, and Ge) and hazardous elements (As, Hg, and Cd) were recovered in the fume dust as oxides. The yields for Zn, Pb, In, and Ge were all higher than 97 %, and the cleaned slag exhibited limited quantities of Pb (23 ppm), As (76 ppm), Hg (<1 ppm), and Cd (<10 ppm), making it suitable for consideration in building applications.


Zhongfu Cheng, Muxing Guo, Bart Blanpain, Annelies Malfliet, Clean recycling of Zn-bearing slags by a plasma fuming process, Chemical Engineering Journal, 2024, 152838, ISSN 1385-8947,


The authors gratefully acknowledge support for this research by VLAIO (SIM Vlaanderen SuperMex project).


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