Integration of preparation of K, Na-embedded activated carbon and reduction of Zn-bearing dusts

Large amounts of solid wastes and flue gases are generated in iron and steel production process, probably leading to serious environmental pollution without duly handle. An innovative and green process of simultaneous reduction of zinc-bearing dusts and activation of low-rank coal was developed and its mechanism was clarified in this paper. Under the optimal conditions, the reduced zinc-bearing dusts containing low harmful elements (0.02% Zn, 0.015 % K and 0.03% Na) could be made as high-quality burden for blast furnace while the low-rank coal was transferred into K, Na-embedded activated carbon, which can be used as effective adsorbent for purification of SO2 and NO-containing flue gases. The solid wastes were successfully utilized to treat the flue gases through the process. The synergetic activation and reduction mechanism in the process was revealed. The coupling effect between reduction reactions of metal oxides in the dusts and activation reaction of carbon in the coal promoted the simultaneous reduction and activation process. In the meanwhile, part of the potassium and sodium from the zinc-bearing dusts could be adsorbed by the activated carbon and played a catalytic role in the activation process. (c) 2022 Published by Elsevier B.V. on behalf of China University of Mining & Technology. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This paper develops an innovative and environmentally friendly process for the simultaneous reduction of zinc-bearing dusts and activation of low-rank coal. It successfully utilizes solid wastes for the treatment of flue gases and reveals the mechanism of the process.