The feasibility of using ultrasound to enhance the performance of de-sulphurization and de-ashing during slime flotation was investigated. The Setararn C80 calorimeter, the contact angle gauge DCAT21 and an electropho...The feasibility of using ultrasound to enhance the performance of de-sulphurization and de-ashing during slime flotation was investigated. The Setararn C80 calorimeter, the contact angle gauge DCAT21 and an electrophoresis apparatus were used to study the surface nature of coal, pyrite and refuse before and after ultrasonic conditioning. The yield, ash and sulfur contents of equally sized coal slimes were also measured before and after ultrasonic conditioning. The results show that ultrasonic conditioning can drive the separation of pyrite and refuse from coal. After ultrasonic conditioning the hydrophobicity of coal and hydrophilicity of pyrite and refuse increase. The perfect index of flotation, the perfect index of de-sulphurization and the percentage of de-sulphurization increase by 22.51%, 25.36% and 2.49%, respectively. This study shows that ultrasonic conditioning can enhance the performance of de-sulphurization and de-ashing of coal flotation methods.展开更多
Coal has been used as an energy resource around the world, primarily for the generation of electricity. The cleaning of coal by removing its unwanted sulfur and mineral matter components is utmost essential before the...Coal has been used as an energy resource around the world, primarily for the generation of electricity. The cleaning of coal by removing its unwanted sulfur and mineral matter components is utmost essential before their gainful utilizations. The ionic liquids （ILs） are considered as non-toxic solvents for using in different industrial processes. The effect of two ILs namely, 1-n-butyl, 3-methylimidazolium tetrafluoro borate （ILl） and 1-n-butyl, 3-methylimidazolium chloride （IL2） in oxidative de-sulfurization and de-ashing of two industrially important high sulfur coal samples from Meghalaya （India） is discussed in this paper. The maximum removal of total sulfur, pyritic sulfur, sulfate sulfur and organic sulfur are observed to be 37.36 %, 62.50 %, 83.33 % and 31.63 % respectively during this oxidative process. The quantitative diffuse reflectance Fourier transform-infrared spectroscopy analysis supports the formation of sulfoxides （S--O） and sulfones （-SO2） and their subsequent removal during the oxidation of the coals in presence of ILs. The X-ray fluorescence combined with near edge X-ray absorption fine structure and scanning electron microscopic studies reveal the removal of mineral matters （ash yields） from the coal samples. The thermogravimetric analysis of the raw and clean coals indicates their high combustion efficiencies and suitability for using in thermal plants. The method is partially green and the ILs could be recovered and reused in the process.展开更多
Energy storage is an important technology in achieving carbon-neutrality goals.Compared with lithium-ion batteries,the raw materials of sodium-ion batteries are abundant,low-cost,and highly safe.Furthermore,their cost...Energy storage is an important technology in achieving carbon-neutrality goals.Compared with lithium-ion batteries,the raw materials of sodium-ion batteries are abundant,low-cost,and highly safe.Furthermore,their costs are expected to be further reduced as large-scale applications take off,making them viable for energy storage applications.The primary anode material for sodium-ion batteries is hard carbon,which has a high sodium-ion storage capacity but is relatively expensive,limiting its applications in energy storage.In order to widen the applications of sodium-ion batteries in energy storage and other fields,it is particularly important to develop anode materials that have both high performance and low cost.Coals,with abundant reserves and worldwide availability,can serve as low-cost carbon sources for anode materials.Additionally,coals of different grades of metamorphism have different structural characteristics that can be tailored for the structural characteristics of coal-based anode materials for sodium-ion batteries.Recent research on tailoring coals as the anode materials for sodium-ion batteries is summarized and the recent progress made towards mitigating the existing issues is analysed in this review.Specifically,the impacts of different grades of metamorphism on the sodium-ion storage performance of coal-based anode materials prepared using direct carbonization are discussed in detail.Studies on improving the electrochemical performances of coal-based anode materials through pore and microcrystalline structure controls and surface as well as interface modifications are presented.Finally,the advantages and disadvantages of different preparation methods are identified.To make the industrial applications of coal-based anode materials for sodium-ion batteries more viable,the importance of the de-ashing process is introduced.展开更多
基金Projects 50274036 supported by the National Natural Science Foundation of China1055G039 by the Mainstay Teacher Originality Innovation Plan Foundation of the Education Department of Heilongjiang Province.
文摘The feasibility of using ultrasound to enhance the performance of de-sulphurization and de-ashing during slime flotation was investigated. The Setararn C80 calorimeter, the contact angle gauge DCAT21 and an electrophoresis apparatus were used to study the surface nature of coal, pyrite and refuse before and after ultrasonic conditioning. The yield, ash and sulfur contents of equally sized coal slimes were also measured before and after ultrasonic conditioning. The results show that ultrasonic conditioning can drive the separation of pyrite and refuse from coal. After ultrasonic conditioning the hydrophobicity of coal and hydrophilicity of pyrite and refuse increase. The perfect index of flotation, the perfect index of de-sulphurization and the percentage of de-sulphurization increase by 22.51%, 25.36% and 2.49%, respectively. This study shows that ultrasonic conditioning can enhance the performance of de-sulphurization and de-ashing of coal flotation methods.
文摘Coal has been used as an energy resource around the world, primarily for the generation of electricity. The cleaning of coal by removing its unwanted sulfur and mineral matter components is utmost essential before their gainful utilizations. The ionic liquids （ILs） are considered as non-toxic solvents for using in different industrial processes. The effect of two ILs namely, 1-n-butyl, 3-methylimidazolium tetrafluoro borate （ILl） and 1-n-butyl, 3-methylimidazolium chloride （IL2） in oxidative de-sulfurization and de-ashing of two industrially important high sulfur coal samples from Meghalaya （India） is discussed in this paper. The maximum removal of total sulfur, pyritic sulfur, sulfate sulfur and organic sulfur are observed to be 37.36 %, 62.50 %, 83.33 % and 31.63 % respectively during this oxidative process. The quantitative diffuse reflectance Fourier transform-infrared spectroscopy analysis supports the formation of sulfoxides （S--O） and sulfones （-SO2） and their subsequent removal during the oxidation of the coals in presence of ILs. The X-ray fluorescence combined with near edge X-ray absorption fine structure and scanning electron microscopic studies reveal the removal of mineral matters （ash yields） from the coal samples. The thermogravimetric analysis of the raw and clean coals indicates their high combustion efficiencies and suitability for using in thermal plants. The method is partially green and the ILs could be recovered and reused in the process.
基金supported by the National Energy Group Project(Grant No.S930023077).
文摘Energy storage is an important technology in achieving carbon-neutrality goals.Compared with lithium-ion batteries,the raw materials of sodium-ion batteries are abundant,low-cost,and highly safe.Furthermore,their costs are expected to be further reduced as large-scale applications take off,making them viable for energy storage applications.The primary anode material for sodium-ion batteries is hard carbon,which has a high sodium-ion storage capacity but is relatively expensive,limiting its applications in energy storage.In order to widen the applications of sodium-ion batteries in energy storage and other fields,it is particularly important to develop anode materials that have both high performance and low cost.Coals,with abundant reserves and worldwide availability,can serve as low-cost carbon sources for anode materials.Additionally,coals of different grades of metamorphism have different structural characteristics that can be tailored for the structural characteristics of coal-based anode materials for sodium-ion batteries.Recent research on tailoring coals as the anode materials for sodium-ion batteries is summarized and the recent progress made towards mitigating the existing issues is analysed in this review.Specifically,the impacts of different grades of metamorphism on the sodium-ion storage performance of coal-based anode materials prepared using direct carbonization are discussed in detail.Studies on improving the electrochemical performances of coal-based anode materials through pore and microcrystalline structure controls and surface as well as interface modifications are presented.Finally,the advantages and disadvantages of different preparation methods are identified.To make the industrial applications of coal-based anode materials for sodium-ion batteries more viable,the importance of the de-ashing process is introduced.
