Properties of ceramics prepared using dry discharged waste to energy bottom ash dust

Abstract

The fine dust of incinerator bottom ash generated from dry discharge systems can be transformed into an inert material suitable for the production of hard, dense ceramics. Processing involves the addition of glass, ball milling and calcining to remove volatile components from the incinerator bottom ash. This transforms the major crystalline phases present in fine incinerator bottom ash dust from quartz (SiO(2)), calcite (CaCO(3)), gehlenite (Ca(2)Al(2)SiO(7)) and hematite (Fe(2)O(3)), to the pyroxene group minerals diopside (CaMgSi(2)O(6)), clinoenstatite (MgSi(2)O(6)), wollastonite (CaSiO(3)) together with some albite (NaAlSi(3)O(8)) and andradite (Ca(3)Fe(2)Si(3)O(12)). Processed powders show minimal leaching and can be pressed and sintered to form dense (>2.5 g cm(-3)), hard ceramics that exhibit low firing shrinkage (<7%) and zero water absorption. The research demonstrates the potential to beneficially up-cycle the fine incinerator bottom ash dust from dry discharge technology into a raw material suitable for the production of ceramic tiles that have potential for use in a range of industrial applications.

Initial studies on the cytotoxicity of ceramics prepared from dry discharge incinerator bottom ash dust

“…The moisture content of the as-received fine IBA determined from the weight loss at 105 °C, was low, as it had not been quenched into water, unlike traditional wet discharged IBA. The dry discharged fine IBA resulted in a pH between 11.5 and 12.5 when placed in water, due to the leaching of alkali and alkali-earth elements into solution [2]. X-ray diffraction (XRD) was used to determine the crystalline phases in the milled powder.…”

“…X-ray diffraction (XRD) was used to determine the crystalline phases in the milled powder. The major crystalline phases present were quartz (SiO 2 ), calcite (CaCO 3 ), gehlenite (Ca 2 Al 2 SiO 7 ) and hematite (Fe 2 O 3 ) [2]. The effect of temperature on mass loss was investigated using thermogravimetric analysis.…”

“…Samples indicated a 16% weight loss when heated to 1000 °C. Significant weight loss occurs between 550 and 850 °C due to decomposition of calcite (CaCO 3 ) to CaO and CO 2 and the decomposition of other volatile phases [2].…”

“…Previous research had demonstrated that the addition of 20 wt.% of recycled soda lime silica glass significantly improved liquid phase sintering of the fine IBA dust [2]. The dry discharged IBA dust can be processed to produce a ceramic with similar but generally improved properties compared to commercially available terracotta ceramics.…”

“…Previous research has demonstrated that the dry discharge dust can be transformed into an inert material suitable for the production of hard, dense ceramics [2]. In order to increase the application potenteial of waste derived products, a complete characterisation of their possible cytotoxicity must be conducted [3].…”