Suppression of chlorinated aromatics by nitrogen and sulphur inhibitors in iron ore sintering. (July 2016)

• Record Type: Journal Article
• Authors: Zhang, Yadi; Buekens, Alfons; Liu, Lina; Zhang, Yibo; Zeng, Xiaolan; Sun, Yifei
• Is Part Of: Chemosphere. Volume 155(2016)
• Page Start: 300
• Page End: 307
• Publication Date: 2016-07
• Subjects: Iron ore sintering -- Fly ash -- Inhibitor -- Chlorinated aromatic compound; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2016.04.065
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Dioxins generated by iron and steel industry account for the majority of industrial dioxins emissions. This study compares the performance of different additives (including calcium sulphate dehydrate CaSO4 ·2H2 O; calcium polysulphide CaSx ; ammonium sulphate (NH4 )2 SO4 ; 4-methylthiosemicarbazide H3 C-SC(NH)2 NH2 and thiourea H2 NCSNH2 ) as suppressant of chlorinated aromatics in iron ore sintering. The formation of chlorobenzenes (CBz) and polychlorinated biphenyls (PCBs), used as surrogates for dioxins, was suppressed significantly in the present of various inhibitors (1 wt%) except for CaSO4 ·2H2 O. Moreover, a larger molar ratio of (S + N)/Cl leads to a higher suppression efficiency, so that the inhibition capacity of (NH4 )2 SO4 on both CBz and PCBs was weaker than H2 NCSNH2 . The generation of dioxin-like PCBs (Co- or dl-PCB) was also analysed. Highlights: Thiourea exhibits the most effective inhibiting effect on CBz and PCB formation. The molar ratio of (S + N)/Cl has an effect on inhibition efficiency. CBz and PCBs prefer report to the solid phase, except dichlorobenzene (DiCBz). The inhibitors have prominent inhibiting effect on dioxin-like PCBs(dl-PCBs).