Details

Autor(en) / Beteiligte

• Zhong, Yin
• Li, Dan
• Mao, Zhe
• Huang, Weilin
• Peng, Ping’an
• Chen, Pei
• Mei, Jun

Titel

Kinetics of tetrabromobisphenol A (TBBPA) reactions with H2SO4, HNO3 and HCl: Implication for hydrometallurgy of electronic wastes

Ist Teil von

• Journal of hazardous materials, 2014-04, Vol.270, p.196-201

Ort / Verlag

Kidlington: Elsevier B.V

Erscheinungsjahr

2014

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• •Effect of hydrometallurgical processes on the fate of TBBPA was evaluated.•TBBPA could react rapidly with HNO3 and concentrated H2SO4.•TBBPA did not show measurable reactivity in HCl and the dilute H2SO4 (≤24wt%).•The reaction kinetics of TBBPA with HNO3 differed from that with concentrated H2SO4.•The transformation pathways of TBBPA in different acids were different. Hydrometallurgy is an acid leaching based process widely used for recovering precious metals from electronic wastes (e-wastes). The effects of acid leaching on the fate of brominated flame retardants (BFRs) in typical hydrometallurgical processes remain largely unknown. This study was aimed at evaluating the fate of tetrabromobisphenol A (TBBPA), a commonly used BFR, in three acid leaching reagents (i.e. H2SO4, HNO3, and HCl) commonly used in hydrometallurgy. It was found that the reactions of TBBPA with concentrated H2SO4 followed a pseudo-zero-order rate and the reaction rates declined rapidly as the concentrations of H2SO4 decreased. In contrast, TBBPA could be easily transformed in less concentrated HNO3 solutions (<21.7wt%) and the reactions followed a pseudo-first-order rate. The reaction products identified by GC–MS indicated different transformation pathways of TBBPA in H2SO4 and HNO3. HCl or HCl/H2SO4 mixtures (3:1, v/v) did not appear to react with TBBPA, while aqua regia (3:1 HCl/HNO3, v/v) reacted violently with TBBPA and led to almost complete disappearance of TBBPA within a minute. It suggested that HNO3 significantly affected the fate of TBBPA and the use of HNO3 as leaching reagents in hydrometallurgy of e-wastes should be carefully evaluated. Collectively, our findings of distinct fate of TBBPA in different acid leaching reagents provided fundamental information for design of hydrometallurgical treatment of e-wastes to minimize acid reactions with BFRs within plastics matrix and to maximize acid leaching efficiency for metals recycling processes.