title: Multifunctional effect of Al2O3, SiO2 and CaO on the volatilization of PbO and PbCl2 during waste thermal treatment.
abstract: Minerals including Al2O3, SiO2 and CaO are predominant matrixes in waste, and are thought to facilitate lead (Pb) emission control. This study distinguished the inhibition of each mineral on common stable Pb-containing compounds, including highly volatile PbCl2 and less volatile PbO. Al2O3 can lower the volatilization temperature of Pb by 29 °C due to the generation of a eutectic compound and play a minor but non-negligible role in reducing Pb volatilization. The most conspicuous inhibition effect was exerted by SiO2 and a mixture of Al2O3 and SiO2, which completely integrated PbO into the glass phase at 690 °C and prohibited its migration. In contrast, SiO2 had no significant inhibition on volatile PbCl2. CaO inhibited PbO volatilization in the absence of oxygen by controlling its diffusion, while it converted PbO to Ca2PbO4 in the presence of oxygen, thus controlling Pb diffusion and decreasing the Pb volatilization ratio and rate. The influence of CaO on PbCl2 was complex because CaO can convert PbCl2 to PbO with formation of CaCl2, and CaCl2 can also be a Cl-donor for PbO. The roles of mineral matrixes in Pb conversion were shown to be important for Pb emission control.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, 1239 Siping Road, Shanghai 200092, PR China; Institute of Waste Treatment and Reclamation, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
authors.forename: Si-Jia
authors.initials: SJ
authors.lastname: Wang
authors.affiliation: Institute of Waste Treatment and Reclamation, Tongji University, 1239 Siping Road, Shanghai 200092, PR China; Centre for the Technology Research and Training on Household Waste in Small Towns & Rural Area, Ministry of Housing and Urban-Rural Development of PR China, 1239 Siping Road, Shanghai 200092, PR China.
authors.forename: Pin-Jing
authors.initials: PJ
authors.lastname: He
authors.affiliation: Institute of Waste Treatment and Reclamation, Tongji University, 1239 Siping Road, Shanghai 200092, PR China; Centre for the Technology Research and Training on Household Waste in Small Towns & Rural Area, Ministry of Housing and Urban-Rural Development of PR China, 1239 Siping Road, Shanghai 200092, PR China.
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Shao
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, 1239 Siping Road, Shanghai 200092, PR China. Electronic address: zhanghua_tj@tongji.edu.cn.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000393:Air Pollutants / Q000737:chemistry*; D000537:Aluminum Oxide / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry*; D017745:Incineration; D007854:Lead / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D014835:Volatilization
chemical_list: D000393:Air Pollutants; D017610:Calcium Compounds; D010087:Oxides; D007854:Lead; C029891:lead chloride; C047365:lead oxide; D012822:Silicon Dioxide; C016538:lime; D000537:Aluminum Oxide
keywords: Inhibition; Lead chloride; Lead oxide; Mineral matrixes; Thermal treatment; Volatilization