title: Extraction of metallic lead from cathode ray tube (CRT) funnel glass by thermal reduction with metallic iron.
abstract: A novel and effective process of thermal reduction treatment with the addition of metallic iron (Fe(0)) to recover lead from cathode ray tube (CRT) funnel glass is introduced. The key technological breakthrough of this process is the use of a relatively lower temperature and an inexpensive reducing agent to extract the metallic lead. The influences of temperature, the reducing agent content, and the holding time for lead reduction were examined to determine the optimal extraction efficiency. The lead extraction efficiency first increased and then decreased with increasing temperature. The maximum lead extraction efficiency occurred at 700 °C. The growth of crystalline lead first increased significantly with an increase in the Fe content, reaching maximum growth at an Fe addition of 50 wt %. The most effective treatment time was determined to be 30 min, as the vitrification of lead back to the glass matrix occurred under longer treatment times. The experimentally derived results indicate that a 58 wt % lead extraction can be achieved with the optimized operational parameters (50 wt % Fe addition, heating at 700 °C for 30 min) in a single extraction operation.
authors.affiliation: Department of Civil Engineering, The University of Hong Kong , Pokfulam Road, Hong Kong, Hong Kong SAR, China.
authors.forename: Xingwen
authors.initials: X
authors.lastname: Lu
authors.forename: Kaimin
authors.initials: K
authors.lastname: Shih
authors.forename: Chengshuai
authors.initials: C
authors.lastname: Liu
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
mesh_terms: D055984:Cathode Ray Tube; D059029:Electronic Waste / Q000032:analysis*; D005898:Glass / Q000737:chemistry*; D055772:Green Chemistry Technology / Q000379:methods; D007501:Iron / Q000737:chemistry; D007854:Lead / Q000737:chemistry*; D016018:Least-Squares Analysis; D008855:Microscopy, Electron, Scanning; D010084:Oxidation-Reduction; D059027:Recycling / Q000379:methods*; D013052:Spectrometry, X-Ray Emission; D013696:Temperature; D013997:Time Factors; D018505:Waste Management / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D007854:Lead; D007501:Iron