title: The recycling of incinerated sewage sludge ash as a raw material for CaO-Al2O3-SiO2-P2O5 glass-ceramic production.
abstract: In this paper, the recycling of incinerated sewage sludge ash (ISSA) into glass-ceramic materials by a two-stage sintering cycle of nucleation stage and crystallization stage without any pressure and binder is presented. The parent glasses were subjected to the following nucleation/crystallization temperature and time level: (A) 790°C, 1.0 h/870°C, 1.0-3.0 h; (B) 790°C, 1.0 h/945°C, 1.0-3.0 h and (C) 790°C, 1.0 h/1065°C, 1.0-3.0 h. X-ray power diffraction analysis results revealed that multiple crystalline phases coexisted in the glass-ceramic materials and the crystalline phase compositions were more affected by crystallization temperature than crystallization time. Scanning electron microscopy analysis showed an interlocking microstructure of glass phases and crystals with different sizes and spatial distribution. The glass-ceramics crystallized at 945°C for 2.0 h exhibited optimal properties of density of 2.88±0.08 g/cm3, compression strength of 247±12 MPa, bending strength of 118±14 MPa and water absorption of 0.42±0.04. The leaching concentrations of heavy metals were far lower than the limits required by the regulatory standard of EPA. This paper provides a feasible, low-cost and promising method to produce ISSA-based glass-ceramics and highlights the principal characteristics that must be taken into account to use ISSA correctly in glass-ceramics.
authors.affiliation: a Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology , Dalian University of Technology , Linggong Road 2, Dalian 116024 , People's Republic of China.
authors.forename: Zhikun
authors.initials: Z
authors.lastname: Zhang
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Yulei
authors.initials: Y
authors.lastname: Yin
authors.forename: Xuanye
authors.initials: X
authors.lastname: Liang
authors.forename: Aimin
authors.initials: A
authors.lastname: Li
mesh_terms: D002516:Ceramics / Q000138:chemical synthesis*; D005898:Glass / Q000737:chemistry*; D017745:Incineration; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D059027:Recycling; D012722:Sewage; D014961:X-Ray Diffraction
chemical_list: D012722:Sewage
keywords: glass-ceramic; heavy metal; incinerated sewage sludge ash; melting/sintering; waste recycling