TY - JOUR
T1 - Effects of mineral change on melting characteristics of MSW incineration fly ash
AU - Luan, Jingde
AU - Yao, Pengfei
AU - Li, Rundong
AU - Chai, Meiyun
AU - Wang, Lei
N1 - Publisher Copyright:
©, 2015, Editorial department of Molecular Catalysis. All right reserved.
PY - 2015/3/1
Y1 - 2015/3/1
N2 - The ash melting test and the techniques of DSC, XRD and SEM were used to investigate the effects of SiO2 additive on the melting behavior of MSW (municipal solid waste) incineration fly ash. Additionally, the reaction activities of produced minerals were analyzed by using the CASTEP model. The results showed that the ash flow temperature was 1355 ℃ when the blending ratio of SiO2 (BRS) was 29.14%, approximately 200 ℃ lower than the original fly ash. The increase of BRS tended to enhance AMT. XRD analysis indicated that wollastonite, pseudowollastonite, gehlenite, andradite, anhydrite and trikalsilite occurred in glass-ceramics. Molecular simulation showed that pseudowollastonite, gehlenite and andradite were refractory minerals due to the high formation energy. Wollastonite, anhydrite and trikalsilite were fluxing minerals and led to the lower AMT. When the mass ratio of SiO2/CaO < 1, excess Ca2+ was prone to combine with reactive oxygen to form pseudowollastonite, which had better thermal stability. When the mass ratio of SiO2/CaO was close to 1, wollastonite, which was the main crystalline phase in glass-ceramics, was considered as fluxing mineral to make AMT reduction. The simulated results indicated that the formation energy of wollastonite (-41.67 eV) was lower than that of other minerals. Moreover, the ratio of reactive oxygen in wollastonite was up to 77.78%. When the mass ratio of SiO2/CaO > 1, a large number of amorphous SiO2 and cristobalite (non-reactive oxygen species) resulted with AMT rise. The percentage change between active oxygen and non-active oxygen in melts was the internal cause of AMT.
AB - The ash melting test and the techniques of DSC, XRD and SEM were used to investigate the effects of SiO2 additive on the melting behavior of MSW (municipal solid waste) incineration fly ash. Additionally, the reaction activities of produced minerals were analyzed by using the CASTEP model. The results showed that the ash flow temperature was 1355 ℃ when the blending ratio of SiO2 (BRS) was 29.14%, approximately 200 ℃ lower than the original fly ash. The increase of BRS tended to enhance AMT. XRD analysis indicated that wollastonite, pseudowollastonite, gehlenite, andradite, anhydrite and trikalsilite occurred in glass-ceramics. Molecular simulation showed that pseudowollastonite, gehlenite and andradite were refractory minerals due to the high formation energy. Wollastonite, anhydrite and trikalsilite were fluxing minerals and led to the lower AMT. When the mass ratio of SiO2/CaO < 1, excess Ca2+ was prone to combine with reactive oxygen to form pseudowollastonite, which had better thermal stability. When the mass ratio of SiO2/CaO was close to 1, wollastonite, which was the main crystalline phase in glass-ceramics, was considered as fluxing mineral to make AMT reduction. The simulated results indicated that the formation energy of wollastonite (-41.67 eV) was lower than that of other minerals. Moreover, the ratio of reactive oxygen in wollastonite was up to 77.78%. When the mass ratio of SiO2/CaO > 1, a large number of amorphous SiO2 and cristobalite (non-reactive oxygen species) resulted with AMT rise. The percentage change between active oxygen and non-active oxygen in melts was the internal cause of AMT.
KW - Active oxygen
KW - Fluxibility
KW - Fly ash melting
KW - Formation energy
UR - http://www.scopus.com/inward/record.url?scp=84926295072&partnerID=8YFLogxK
U2 - 10.13198/j.issn.1001-6929.2015.03.16
DO - 10.13198/j.issn.1001-6929.2015.03.16
M3 - 文章
AN - SCOPUS:84926295072
SN - 1001-6929
VL - 28
SP - 447
EP - 452
JO - Research of Environmental Sciences
JF - Research of Environmental Sciences
IS - 3
ER -
