The basic principle of fly ash triboelectrification is analysed. The mineral electrical index and test method are introduced. The electric difference of different mineral composition of fly ash is discussed by analysi...The basic principle of fly ash triboelectrification is analysed. The mineral electrical index and test method are introduced. The electric difference of different mineral composition of fly ash is discussed by analysis of chemical and mineral composition of fly ash in Xinwen power plant. The dielectric constant and charge-mass ratio of carbon and ash of fly ash are tested. Combined with the experimental study on rotary triboelectrostatic separation, the charged characteristic of fly ash particles with different size is gained. The results show that the dielectric constant of fly ash with different grain size decreased with the decrease of particle size, which lead to the poor electrical conductivity, Thus it can be seen that par- ticle size plays a leading role in conductivity, The charge of carbon and ash with each size increased with the decreased of particle size; and the charge-mass ratio between carbon and ash with the same size lar- ger with the decrease of size, which indicated that the finer particle size, the more favorable for triboelec- trification separation. In the same conditions, the best decarburization effect is realized when the particle size ranges from 0.038 to 0.074 ram, whose decarbonization rate and efficiency index reached 38.93% and 120.83% respectively.展开更多
The mineralogy of shock vein matrix in the Suizhou meteorite has been investigated by optical and transmission electron microscopy. It was revealed that the vein matrix is composed of majorite-pyrope garnet, mag- aesi...The mineralogy of shock vein matrix in the Suizhou meteorite has been investigated by optical and transmission electron microscopy. It was revealed that the vein matrix is composed of majorite-pyrope garnet, mag- aesiowtistite, and ringwoodite, with FeNi-FeS inter- growths. The observation and character of ring-like selected electron diffraction （SAED） patterns indicate that Lhe idiomorphic garnet crystals in the vein matrix have different orientations. The polycrystalline nature of magnesiowtistite is also confirmed by a ring-like SAED pattern. Both garnet and magnesiowtistite crystals showed sharp Jiffraction spots, signifying the good crystallinity of these ：wo minerals. The SAED pattern of cryptocrystalline 5ngwoodite shows only diffuse concentric diffraction tings. FeNi metal and troilite （FeS）, which were molten during the shock event, occur in the matrix as fine eutectic FeNi-FeS intergrowths filling the interstices between garaet and magnesiowiistite grains. Based on the phase dia- gram of the Allende chondrite and the results of this TEM study, it is inferred that majorite-pyrope garnet first crystallized from the Suizhou chondritic melt at 22-26 GPa, Followed by crystallization of magnesiowtistite at 20-24 GPa, and then ringwoodite at 18-20 GPa. The eutectic intergrowths of FeNi-metal and troilite are proposed to have crystallized during meteorite cooling and solidified at the last stage of vein formation.展开更多
The dependence of starting materials and their initial grain sizes on the formation of gases （H2, CH4, C2H6 and C3Hs） during serpentinization was investigated by conducting hydrothermal experiments at 311℃ and 3 kb...The dependence of starting materials and their initial grain sizes on the formation of gases （H2, CH4, C2H6 and C3Hs） during serpentinization was investigated by conducting hydrothermal experiments at 311℃ and 3 kbar on olivine and peridotite with initial grain sizes ranging from 〈30 to 177 μm. Hydrocarbons （CH4, C2H6 and C3H8） were produced from reaction between dissolved CO2 in the starting fluids and HE formed during serpentinization, which were analyzed by Gas Chromatography. It was found that olivine serpentinization produced much less H2 and CH4 compared with those after peridotite alteration, while their C2H6 and C3H8 were identical. For example, for olivine with initial grain sizes of 〈30 μm, the amounts of HE and CH4 were 79.6 mmol/kg and 460 μmol/kg after 27 days, respectively. By contrast, the quantities of H2 and CH4 produced in experiment on peridotite with the same run duration were much larger, 119 mmol/kg and 1300 μmol/kg, respectively. This indicates that spinel and pyroxene in peridotite may increase the amounts of HE and hydrocarbons, possibly due to the catalytic effect of aluminum released by spinel and pyroxene during serpentinization. Moreover, the production of H2 and hydrocarbons is negatively correlated with initial grain sizes of the starting material, with smaller amounts of HE and hydrocarbons for larger initial grain sizes, indicating that the kinetics of serpentinization influences the formation of HE and hydrocarbons, possibly because of the lack of catalytic minerals for the starting material with larger grain sizes. This study suggests that olivine cannot completely represent peridotite during serpentinization, and that H2 and hydrocarbons in hydrothermal fields near the mid-ocean ridge may be produced in a very long period of serpentinization or the presence of catalytic minerals due to large grain sizes of ultramafic rocks.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51274200 and 51221462)
文摘The basic principle of fly ash triboelectrification is analysed. The mineral electrical index and test method are introduced. The electric difference of different mineral composition of fly ash is discussed by analysis of chemical and mineral composition of fly ash in Xinwen power plant. The dielectric constant and charge-mass ratio of carbon and ash of fly ash are tested. Combined with the experimental study on rotary triboelectrostatic separation, the charged characteristic of fly ash particles with different size is gained. The results show that the dielectric constant of fly ash with different grain size decreased with the decrease of particle size, which lead to the poor electrical conductivity, Thus it can be seen that par- ticle size plays a leading role in conductivity, The charge of carbon and ash with each size increased with the decreased of particle size; and the charge-mass ratio between carbon and ash with the same size lar- ger with the decrease of size, which indicated that the finer particle size, the more favorable for triboelec- trification separation. In the same conditions, the best decarburization effect is realized when the particle size ranges from 0.038 to 0.074 ram, whose decarbonization rate and efficiency index reached 38.93% and 120.83% respectively.
基金financially supported by National Natural Science foundation of China under Grant 41172046 and 40972044 in part
文摘The mineralogy of shock vein matrix in the Suizhou meteorite has been investigated by optical and transmission electron microscopy. It was revealed that the vein matrix is composed of majorite-pyrope garnet, mag- aesiowtistite, and ringwoodite, with FeNi-FeS inter- growths. The observation and character of ring-like selected electron diffraction （SAED） patterns indicate that Lhe idiomorphic garnet crystals in the vein matrix have different orientations. The polycrystalline nature of magnesiowtistite is also confirmed by a ring-like SAED pattern. Both garnet and magnesiowtistite crystals showed sharp Jiffraction spots, signifying the good crystallinity of these ：wo minerals. The SAED pattern of cryptocrystalline 5ngwoodite shows only diffuse concentric diffraction tings. FeNi metal and troilite （FeS）, which were molten during the shock event, occur in the matrix as fine eutectic FeNi-FeS intergrowths filling the interstices between garaet and magnesiowiistite grains. Based on the phase dia- gram of the Allende chondrite and the results of this TEM study, it is inferred that majorite-pyrope garnet first crystallized from the Suizhou chondritic melt at 22-26 GPa, Followed by crystallization of magnesiowtistite at 20-24 GPa, and then ringwoodite at 18-20 GPa. The eutectic intergrowths of FeNi-metal and troilite are proposed to have crystallized during meteorite cooling and solidified at the last stage of vein formation.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.4109037341121002+2 种基金41103012 and 41173069)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB06030100)also by Postdoctoral Science Foundation of China(Grant No.2015M570735)
文摘The dependence of starting materials and their initial grain sizes on the formation of gases （H2, CH4, C2H6 and C3Hs） during serpentinization was investigated by conducting hydrothermal experiments at 311℃ and 3 kbar on olivine and peridotite with initial grain sizes ranging from 〈30 to 177 μm. Hydrocarbons （CH4, C2H6 and C3H8） were produced from reaction between dissolved CO2 in the starting fluids and HE formed during serpentinization, which were analyzed by Gas Chromatography. It was found that olivine serpentinization produced much less H2 and CH4 compared with those after peridotite alteration, while their C2H6 and C3H8 were identical. For example, for olivine with initial grain sizes of 〈30 μm, the amounts of HE and CH4 were 79.6 mmol/kg and 460 μmol/kg after 27 days, respectively. By contrast, the quantities of H2 and CH4 produced in experiment on peridotite with the same run duration were much larger, 119 mmol/kg and 1300 μmol/kg, respectively. This indicates that spinel and pyroxene in peridotite may increase the amounts of HE and hydrocarbons, possibly due to the catalytic effect of aluminum released by spinel and pyroxene during serpentinization. Moreover, the production of H2 and hydrocarbons is negatively correlated with initial grain sizes of the starting material, with smaller amounts of HE and hydrocarbons for larger initial grain sizes, indicating that the kinetics of serpentinization influences the formation of HE and hydrocarbons, possibly because of the lack of catalytic minerals for the starting material with larger grain sizes. This study suggests that olivine cannot completely represent peridotite during serpentinization, and that H2 and hydrocarbons in hydrothermal fields near the mid-ocean ridge may be produced in a very long period of serpentinization or the presence of catalytic minerals due to large grain sizes of ultramafic rocks.
