Fate of lead oxide during thermal treatment with tetrabromobisphenol A.
In this paper, the bromination reaction between lead oxide and hydrogen bromide originating from the thermal decomposition of tetrabromobisphenol A (TBBPA), under inert and oxidizing atmospheres, was investigated, using a laboratory-scale furnace. The results obtained under inert conditions indicated that bromination of PbO proceeded simultaneously with debromination of TBBPA, with an average effectiveness of 69% (max. 80%). Volatilization of the formed PbBr2 began at 315°C, intensified at 750°C, and reached 98% at 850°C. The formed organic char served as a source of carbon for reduction of the unreacted lead oxide to metallic lead in the range 315-750°C. Additional experiments conducted at selected temperatures under slightly oxidizing (5 vol% O2) and quasi-atmospheric (20 vol% O2) conditions showed no significant effects on bromination-evaporation of lead in the studied mixture. However, in isothermal treatment under quasi-atmospheric oxygen levels, complete vaporization of the formed lead bromide was obtained at a temperature of only 650°C.
Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 1,1 Katahira, 2-Chome, Aoba-ku, Sendai 980-8577, Japan; Institute of Environmental Engineering of the Polish Academy of Sciences, M. Sklodowska-Curie 34, 41-819 Zabrze, Poland. Electronic address: sylwia_oleszek@yahoo.com.
Sylwia
S
Oleszek
Mariusz
M
Grabda
Etsuro
E
Shibata
Takashi
T
Nakamura
D005411:Flame Retardants; D006358:Hot Temperature; D018054:Hydrobromic Acid / Q000737:chemistry*; D007220:Industrial Waste; D007854:Lead / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D011075:Polybrominated Biphenyls / Q000737:chemistry*; D014835:Volatilization; D018505:Waste Management / Q000379:methods
D005411:Flame Retardants; D007220:Industrial Waste; D010087:Oxides; D011075:Polybrominated Biphenyls; D007854:Lead; D018054:Hydrobromic Acid; C047365:lead oxide; C020806:tetrabromobisphenol A
Bromination–vaporization process; Lead recovery; Safe disposal of EAF dust; WEEE utilization