Physical-mechanical and environmental properties of sintered municipal incinerator fly ash

Incineration Fly Ash and Its Treatment to Possible Utilization: A Review

“…According to experimental results, higher sintering temperature led to more volatilization of heavy metals, and the lowest value for the overall pollution toxicity index (OPTI) was at 1040 • C. The authors of [159] conclude that, at lower temperatures and shorter times, higher integrated control efficiency conditions of heavy metals were achieved. Some suggested various pretreatments such as water washing, ball milling, sieving and pelletizing of the ash [154,[160][161][162][163]. These pretreatments are comparable to traditional ceramic processing as the glass-ceramics produced by the sintering process often undergoes pre-melting [164].…”

Metal removal from Municipal Solid Waste Incineration fly ash: A comparison between chemical leaching and bioleaching

“…Despite some treatment strategies have been proposed and commercialised, the experimental results don't suffice to validate a more widespread implementation. For example, treat ment options for the production of glass ceramic, cement clinkers, geo polymers, synthetic zeolites or other adsorbents from MSWI fly ashes were found to be inefficient for the complete stabilisation of hazardous compounds and/or for the conversion of raw fly ashes into a material with good mechanical characteristics (e.g., De Casa et al, 2007); hydrometallurgical methods for metals recovery have the disadvantage of a massive use of mineral acid and still lack in well targeted techniques for the (re)precipitation of metals from the enriched solutions. Due to these technology gaps the manage ment of fly ash still represents a huge cost for MSWI companies.…”

SEM/EDS and XRD characterization of raw and washed MSWI fly ash sintered at different temperatures

“…9b). As determined by EDS, the predominant elements in WFA were Ca, S, Si, Zn, O, Al and Mg. Due to the high solubility in water, most of the chlorides were removed by the washing treatment [9]; the content of Cl in WFA was very low, compared with the raw fly ash (Table 1). According to Table 3, the major compounds containing Zn were Na 12 [Zn 12 P 12 O 48 ]·12H 2 O, ZnS, Ca 2 ZnSi 2 O 7 and Zn 2 SiO 4 .…”

“…A lot of researches suggested that a preliminary washing treatment of raw fly ash with water represents a basic step for successful thermal processing of such a material [7][8][9]. The results from Wang et al [8] indicate that calcium-containing aluminosilicates with a relatively low-melting point are newly formed in the residual ash during the water extraction process, which are thought to contribute to the heavy metal stability in the washed ash, through binding mechanism in the silicate structure.…”