Valuable metal extraction technology from thermal power plant fly ash is limited.In the present study,aluminium is extracted from fly ash as highly pure aluminium sulphate(>99.0%)by leaching with sulphuric acid,fol...Valuable metal extraction technology from thermal power plant fly ash is limited.In the present study,aluminium is extracted from fly ash as highly pure aluminium sulphate(>99.0%)by leaching with sulphuric acid,followed by pre-concentration and successive crystallization.Two types of fly ashes from different sources,i.e.,Talcher Thermal Power Station(TTPS)and Vedanta Aluminium Company Limited(VAL)were chosen for comparative study on the extraction of aluminium as aluminium sulphate.The product is characterized by powder X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR)and thermogravimetric analysis(TGA).Purity of aluminium sulphate was also investigated by inductively coupled plasma?optical emission spectrometry(ICP?OES).The extraction efficiency of aluminium depends on the varied solid-to-liquid ratio(fly ash:18mol/L H2SO4,g/mL)and particle size of fly ashes.Physico-chemical analysis indicates that the obtained product is Al2(SO4)3·18H2O,having low iron content(0.08%).展开更多
In this study,various ZSM-5/MCM-41 micro/mesoporous zeolite composites have been prepared by alkalidesilication and surfactant-directed recrystallization of ZSM-5.The effects of particle size and Si/Al ratio of initia...In this study,various ZSM-5/MCM-41 micro/mesoporous zeolite composites have been prepared by alkalidesilication and surfactant-directed recrystallization of ZSM-5.The effects of particle size and Si/Al ratio of initial ZSM-5 zeolites on the structure and catalytic performance of ZSM-5/MCM-41 composites are studied.The results of XRD,TEM N_2-adsorption-desorption,NH_3-TPD and in situ FT-IR revealed that ordered hexagonal MCM-41 mesopores with 3-4 nm pore size were formed around ZSM-5 crystals,and the specific surface area and mesopore volume of composites increased with increasing the Si/Al ratio of initial ZSM-5.Catalytic cracking of n-dodecane(550℃,4 MPa) showed that the ZSM-5/MCM-41 composites obtained from the high Si/Al ratio and nano-sized initial ZSM-5 zeolites exhibited superior catalytic performance,with the improvement higher than 87%in the catalytic activities and 21%in the deactivation rate compared with untreated zeolites.This could be ascribed to their suitable pore structure,which enhanced the diffusion of reactant molecules in pores of catalysts.展开更多
基金Funding from CSIR, New Delhi, under network project (ESC.205)
文摘Valuable metal extraction technology from thermal power plant fly ash is limited.In the present study,aluminium is extracted from fly ash as highly pure aluminium sulphate(>99.0%)by leaching with sulphuric acid,followed by pre-concentration and successive crystallization.Two types of fly ashes from different sources,i.e.,Talcher Thermal Power Station(TTPS)and Vedanta Aluminium Company Limited(VAL)were chosen for comparative study on the extraction of aluminium as aluminium sulphate.The product is characterized by powder X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR)and thermogravimetric analysis(TGA).Purity of aluminium sulphate was also investigated by inductively coupled plasma?optical emission spectrometry(ICP?OES).The extraction efficiency of aluminium depends on the varied solid-to-liquid ratio(fly ash:18mol/L H2SO4,g/mL)and particle size of fly ashes.Physico-chemical analysis indicates that the obtained product is Al2(SO4)3·18H2O,having low iron content(0.08%).
基金Supported by the National Natural Science Foundation of China(U123213421306132)the Doctoral Program of Higher Education(20120032120008)
文摘In this study,various ZSM-5/MCM-41 micro/mesoporous zeolite composites have been prepared by alkalidesilication and surfactant-directed recrystallization of ZSM-5.The effects of particle size and Si/Al ratio of initial ZSM-5 zeolites on the structure and catalytic performance of ZSM-5/MCM-41 composites are studied.The results of XRD,TEM N_2-adsorption-desorption,NH_3-TPD and in situ FT-IR revealed that ordered hexagonal MCM-41 mesopores with 3-4 nm pore size were formed around ZSM-5 crystals,and the specific surface area and mesopore volume of composites increased with increasing the Si/Al ratio of initial ZSM-5.Catalytic cracking of n-dodecane(550℃,4 MPa) showed that the ZSM-5/MCM-41 composites obtained from the high Si/Al ratio and nano-sized initial ZSM-5 zeolites exhibited superior catalytic performance,with the improvement higher than 87%in the catalytic activities and 21%in the deactivation rate compared with untreated zeolites.This could be ascribed to their suitable pore structure,which enhanced the diffusion of reactant molecules in pores of catalysts.
