Thermal behaviors, combustion mechanisms, evolved gasses, and ash analysis of spent potlining for a hazardous waste management
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Dosyalar
Tarih
2021
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Chinese Academy of Sciences
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
An unavoidable but reusable waste so as to enhance a more circular waste utilization has been spent potlining (SPL) generated by the aluminum industry. The combustion mechanisms, evolved gasses, and ash properties of SPL were characterized dynamically in response to the elevated temperature and heating rates. Differential scanning calorimetric (DSC) results indicated an exothermic reaction behavior probably able to meet the energy needs of various industrial applications. The reaction mechanisms for the SPL combustion were best described using the 1.5-, 3- and 2.5-order reaction models. Fluoride volatilization rate of the flue gas was estimated at 2.24%. The SPL combustion emitted CO2, HNCO, NO, and NO2 but SOx. The joint optimization of remaining mass, derivative thermogravimetry, and derivative DSC was achieved with the optimal temperature and heating rate combination of 783.5 °C, and 5 °C/min, respectively. Interaction between temperature and heating rate exerted the strongest and weakest impact on DSC and remaining mass, respectively. The fluorine mainly as the formation of substantial NaF and CaF2 in the residual ash. Besides, the composition and effect of environment of residual solid were evaluated. The ash slagging tendency and its mineral deposition mechanisms were elucidated in terms of turning SPL waste into a benign input to a circular waste utilization.
Açıklama
Anahtar Kelimeler
Gas Emission, Heat Release, Reaction Mechanism, Spent Potlining, Thermal Decomposition
Kaynak
Journal of Environmental Sciences (China)
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
107