Production of pyroxene ceramics from the fine fraction of incinerator bottom ash

Abstract

16The fine fraction of incinerator bottom ash (IBA) generated from dry discharge systems can be 17 transformed into an inert material suitable for the production of hard, dense ceramics. Processing 22Processed powders show minimal leaching and can be pressed and sintered to form dense (>2.5 g/cm 33The combustion of residual waste in Energy-from-Waste (EfW) facilities is widely used in many 34 developed countries. There are currently 30 EfW facilities operating in Switzerland and ~450 plants in 35Europe. EfW processes residual municipal solid waste (MSW), which is the material remaining after the 36 maximum amount of commercially viable recyclable materials have been extracted, and the heat 37 generated is used to produce electricity and/or steam and/or hot water for district heating schemes (Nixon 38 et al., 2013). The incinerator bottom ash (IBA) produced is a heterogeneous mix of ceramic, glass, brick, 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 F o r P e e r R e v i e w 2 concrete, clinker and particles of fused materials. IBA also contains significant levels of ferrous (~ 10 wt. 40%) and non-ferrous metals (~1-3 wt. %), mainly Cu and Al. 41The amount of IBA produced is typically 20 to 25 wt. % of the input residual MSW to an EfW plant, 42and it is normally quenched into water on exiting the combustion chamber, producing wet-discharged 43IBA. Alternative dry discharge systems operate at some EfW facilities and these have significant 44 advantages including more efficient metal recovery and lower operating energy requirements (Allegrinia 45 et al., 2014). A schematic diagram of the Martin grate-based combustion and dry bottom ash discharge 46 system operating at the Monthey EfW plant in Switzerland is shown in Figure 1 (Blatter et.al., 2014). A 47 nearly metal-free fine fraction of IBA (<1 mm) is separated by an air separator and a dust extraction. The 48 coarse fraction, in which almost all metals are present, undergoes appropriate separating processes in 49 order to extract the metals. The fine IBA fraction from the Monthey plant is currently reused as a cement 50 substitute together with cement for stabilizing neutral washed filter ashes prior to disposal in a hazardous 51 landfill (Koralewska et.al, 2014). 52The production of ceramics and glass-ceramics from IBA has been extensively reported. The ceramic 53 manufacturing process normally involves milling raw materials to reduce particle size and increase 54 sintering reactivity, spray drying to produce granules suitable for pressing, and sintering of the compacted 55 powder. The production of glass-ceramic involves the production of a glass by melting the raw materials 56 at high temperature, followed by subsequent heat treatment at lower temperatures to induce 57 crystallization effects. A major advantage of these types of processing is their ability ...

Particle Size and Potential Toxic Element Speciation in Municipal Solid Waste Incineration (MSWI) Bottom Ash

“…BA sorting produces new waste with the further disadvantage that smaller sized grains provide a larger reaction surface and, possibly, higher leaching of heavy metals already present at significant concentrations [14,15,[23][24][25]. Recovery of the smaller fraction of the BA was proposed in regard to pyroxene glass ceramics by heating at a high temperature [26]. However, characterization through different sizes of the BA is required to plan any process of recovery.…”

Ceramics from Municipal Waste Incinerator Bottom Ash and Wasted Clay for Sensible Heat Storage at High Temperature

“…5. It appears that the fired density variations between samples were minor, all of them exhibiting values between 1.75 and 1.91 g/cm 3 . Depending on the composition, the maximum density was obtained at different temperatures.…”

Applying Mixture of Municipal Incinerator Bottom Ash and Sewage Sludge Ash for Ceramic Tile Manufacturing

“…They assessed the suitability of MIBA to replace 0, 10, 20, 30, 50, 75, or 100% of natural fine aggregates in masonry blocks (100 mm high × 215 mm wide × 440 mm long) with a design strength of 7 N. The results indicated that MIBA replacement levels below 20% provide adequate compression and tensile strengths with density and absorption also within satisfactory levels [ 17 ]. Bourtsalas et al mixed a fine fraction of MIBA (under 4 mm) with glass and transformed by milling, calcining, pressing, and sintering into high-density ceramics [ 18 ]. In Italy, Schabbach et al demonstrated the obtainment of new ceramics based on a huge amount (60 wt %) of post-treated MIBA and 40 wt % of refractory clay [ 19 ].…”