Performance of sintering process to synthesize cementitious materials and to stabilize heavy metals from MSWI fly ash and water sludge

다국어 초록 (Multilingual Abstract)

This study proposes a method to manufacture cementitious materials with municipal solid waste incineration fly ash (MF)and water sludge (WS) sintered at temperatures ranging from 10008C to 13008C. The utilized wastes contain a variety of cement components, such as Ca, Al, Cl, Si and SO3. The mixing ratio of MF to WS was determined according to the stoichiometry molar ratio of Ca/Al of calcium chloroaluminate, Ca12Al14O32Cl2. When the mixture was sintered at sintering temperature between 1000oC and 1100oC, calcium chloroaluminate (Ca12Al14Cl2O32) and melilite (Ca4Al2MgSi3O14) were formed as cementitious materials, and calcium sulfoaluminate (Ca4Al6SO14) was formed accompanying the consumption of calcium chloroaluminate starting at a sintering temperature of 1200oC. In the hydration reaction, calcium chloroaluminate,melilite and calcium sulfoaluminate synthesized through the sintering process formed Ca4Al2Cl2O6·10(H2O),Ca5Al2(OH)4Si3O12 and ettringite (Ca6Al2(SO4)3(OH)12·26H2O), respectively, as hydrates. The leaching concentrations of heavy metals (As, Cd, Cr, Cu, Pb and Zn) from the sintered products were well below Korea’s regulatory levels for such elements.

참고문헌 (Reference)

1 허종, "Vitrification of fly ash from municipal solid waste incinerator" ELSEVIER SCIENCE BV 91 (91): 83-93, 200201

2 Pera, J, "Use of incinerator bottom ash in concrete" 27 (27): 1-5, 1997

3 Taylor, H. F. W, "The chemistry of cements (3rd ed.)" Academic Press 1979

4 Chang, J, "Study on the composition and hydration of alinite and calcium chloroaluminate minerals" 35 : 248-255, 2005

5 Ikeda, K, "Structure refinement of calcium sulfoaluminate, with emphasis to oxygen deficiency" 26 : 743-748, 1996

6 Karamanov, A, "Sintered glass-ceramics from municipal solid waste-incinerator fly ashes, In Part I: The influence of the heating rate on the sintercrystallisation" 23 : 827-832, 2003

7 Saikia, N, "Shigeru Kato,ToshinoriKojima, Production of cement clinkers from municipal solid waste incineration (MSWI) fly ash" 27 : 1178-1189, 2007

8 Liu, Y, "SEM/EDS and XRD characterization of raw and washed MSWI fly ash at different temperatures" 162 : 161-173, 2009

9 Kirby, C. S, "Mineralogy and surface properties of municipal solid waste ash" 27 : 652-660, 1993

10 Polettini, A, "Engineering and environmental properties of thermally treated mixtures containing MSWI flay ash and low cost additives" 56 : 901-910, 2004

11 Hjelamr, Ole, "Disposal strategies for municipal solid waste incineration residues" 47 : 345-368, 1996

12 Shim, Y. S, "Comparison of leaching characteristics of heavy metals from bottom and fly ashes in Korea and Japan" 25 : 473-480, 2005

13 You Kwang-Suk, "Change morphology and crystal structure in ettringite by trivalent chromium" 545 : 529-532, 2007

14 Lide, D. R, "CRC handbook of chemistry and physics(74th ed. )" Boca Raton 1993