Title: Polychlorinated dibenzo-p-dioxins and dibenzofurans in off-gas and residue during desulphurisation of iron ore sintering off-gas

Authors: Yibo Zhang; Rong Zhu; Jingling Yang; Alfons Buekens; Hui Wang; Yun Wang; Pu Zhang

Addresses: Central Research Institute of Building and Construction, MCC Group, No. 33, Xitucheng Road, Haidian District, Beijing 100088, China; School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, No. 30, Xueyuan Road, Haidian District, Beijing 100083, China ' School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, No. 30, Xueyuan Road, Haidian District, Beijing 100083, China ' Central Research Institute of Building and Construction, MCC Group, No. 33, Xitucheng Road, Haidian District, Beijing 100088, China ' State Key Laboratory of Clean Energy Utilisation, Zhejiang University, No. 866, Yuhangtang Road, Xihu District, Hangzhou 310058, China ' Central Research Institute of Building and Construction, MCC Group, No. 33, Xitucheng Road, Haidian District, Beijing 100088, China ' School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, No. 30, Xueyuan Road, Haidian District, Beijing 100083, China ' Central Research Institute of Building and Construction, MCC Group, No. 33, Xitucheng Road, Haidian District, Beijing 100088, China

Abstract: In this study, the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), in brief dioxins (PCDD/Fs), were measured in the off-gas and solid by-products from two selected and distinct desulphurisation processes, one operating wet and one dry on sintering off-gas. All samples analysed showed a PCDFs to PCDDs ratio larger than unity. The removal efficiencies obtained in the two facilities were almost identical, about 40%, when based on the toxic equivalent quantity (TEQ), and the removal efficiency of PCDD/Fs was higher. Unexpectedly, the removal efficiency was strongly dependent on chlorination level and far higher for low chlorinated PCDD/Fs than for high chlorinated PCDD/Fs, showing even negative removal efficiency. Moreover, the Hagenmaier profile was markedly different for the gas phase samples than for residue. These findings suggest that during desulphurisation both physical effects, such as adsorption, chemical reactions, as well as memory effects may have occurred.

Keywords: PCDD/Fs; desulphurisation; iron ore sintering; off-gas cleaning; by-product.

DOI: 10.1504/IJEP.2018.097861

International Journal of Environment and Pollution, 2018 Vol.63 No.4, pp.271 - 282

Received: 26 Jun 2017
Accepted: 24 Jul 2018
Published online: 20 Feb 2019 *

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