An acidic mixture of sulfuric and fluosilicic acid(H_(2)SO_(4)+H_(2)SiF_(6))was employed as lixiviant to enhance leaching of lithium from lepidolite.The H_(2)SiF_(6) was obtained as a byproduct of anhydrous hydrofluor...An acidic mixture of sulfuric and fluosilicic acid(H_(2)SO_(4)+H_(2)SiF_(6))was employed as lixiviant to enhance leaching of lithium from lepidolite.The H_(2)SiF_(6) was obtained as a byproduct of anhydrous hydrofluoric acid production,aiming to provide HF molecules.It was found that the HF molecules were the main reaction component and played a key role in strengthening the dissolution of lepidolite.Different factors,including mass ratio of ore/H_(2)SO_(4)/H_(2)SiF_(6),concentrations of H_(2)SO_(4) and H_(2)SiF_(6),leaching temperatures(40−80℃)and time(15−75 min),were investigated.Moreover,an efficient tubular reactor was employed to improve this acid leaching system.Under the optimal conditions(ore/H_(2)SO_(4)/H_(2)SiF_(6) mass ratio of 1:0.8:1.6,80 wt.% H_(2)SO_(4),15 wt.% H_(2)SiF_(6),80℃,15 min),97.9% of Li,96.4% of K,97.6% of Rb,96.7% of Cs and 81.4% of Al(mass fraction)were leached.Additionally,a two-step thermal process was proposed to remove fluorine of leaching slurry.This acid treatment using an acidic mixture of H_(2)SO_(4) and H_(2)SiF_(6) in a continuous tubular reactor shows potential as an alternative process to extract lithium from lepidolite.展开更多
To examine spatial variations of grain-size characteristics caused by both natural and human-induced processes along the Lianyungang muddy coast, China, 129 samples were collected and measured using standard sieving a...To examine spatial variations of grain-size characteristics caused by both natural and human-induced processes along the Lianyungang muddy coast, China, 129 samples were collected and measured using standard sieving and sedimentation techniques. Results show that sediment diameter tends to increase with increasing water depth from nearshore to offshore. Size-frequency distributions indicate a gradual mixing process of coarse and fine diameter material. Grain size trend analysis indicates that a man-made structure, the West has resulted in severe siltation in Haizhou Bay and Breakwater, along with Liandao Island itself, the Lianyungang port area, where sediment quality is also poor. Results demonstrate that grain size can be used as a natural tracer to infer how sediments respond to the effects caused by both natural and human-induced processes.展开更多
In this paper,research is conducted on the characteristics of coda Q values of the Jiangsu area,based on the Aki single backscattering model with the waveforms recorded by the Jiangsu digital seismic network. The resu...In this paper,research is conducted on the characteristics of coda Q values of the Jiangsu area,based on the Aki single backscattering model with the waveforms recorded by the Jiangsu digital seismic network. The results show that the Jiangsu area is a high Q value area as a whole,but the Q value differs obviously between different regions,characterized generally as high in the south and low in the north. This study focuses on 4 sub-regions where the stations are relatively dense,the tectonic features are distinguishing,and the calculation results of coda Q0 are fairly concentrated,and obtains the characteristic relationship between the Q value and frequency of the 4 regions. The region from south Jiangsu to the Yangtze River estuary and that around the Maoshan fault zone are the high Q value areas in Jiangsu; the region from central Jiangsu to the waterfront area is the low Q value area in Jiangsu Province,and the Lianyungang region in northern Jiangsu is the moderate Q value area. Comparing the tectonic activity and seismicity of the 4 different Q value sub-regions,there is a certain correlation between Q value,crustal movement and seismicity.展开更多
Climate affects Picea crassifolia growth and climate change will lead to changes in the climate–growth relationship(i.e., the "divergence" phenomenon). However, standardization methods can also change the u...Climate affects Picea crassifolia growth and climate change will lead to changes in the climate–growth relationship(i.e., the "divergence" phenomenon). However, standardization methods can also change the understanding of such a relationship. We tested the stability of this relationship by considering several variables: 1) two periods(1952–1980 and 1981–2009), 2) three elevations(2700, 3000, and 3300 m), and 3) chronologies detrended using cubic splines with two different flexibilities. With increasing elevation, the climatic factor limiting the radial growth of Picea crassifolia shifted from precipitation to temperature. At the elevation of 2700 m, the relationship between radial growth and mean temperature of the previous December changed so that the more flexible spline had a greater precipitation signal. At the elevation of 3000 m, positive correlation of radial growth with mean temperature and precipitation in September of the previous year became more significant. At the elevation of 3300 m, positive correlation between radial growth and precipitation of the currentsummer and the previous spring and autumn was no longer significant, whereas the positive correlation between radial growth and temperature of the current spring and summer strengthened. The detrending with the most flexible spline enhanced the precipitation signal at 2700 m, while that with the least flexible spline enhanced the temperature signal at 3300 m. All results indicated that the divergence phenomenon was affected by the climatic signals in the chronologies and that it was most dependent on the detrending method. This suggests it is necessary to select a suitable spline bootstrap for studies of growth divergence phenomena.展开更多
基金the financial supports from Natural Science Foundation of Henan,China(No.212300410278)Henan Provincial Key Research and Development Program,China(No.212102310371)+1 种基金Henan Postdoctoral Foundation,China(No.202002020)China Postdoctoral Science Foundation(No.2020M682353).
文摘An acidic mixture of sulfuric and fluosilicic acid(H_(2)SO_(4)+H_(2)SiF_(6))was employed as lixiviant to enhance leaching of lithium from lepidolite.The H_(2)SiF_(6) was obtained as a byproduct of anhydrous hydrofluoric acid production,aiming to provide HF molecules.It was found that the HF molecules were the main reaction component and played a key role in strengthening the dissolution of lepidolite.Different factors,including mass ratio of ore/H_(2)SO_(4)/H_(2)SiF_(6),concentrations of H_(2)SO_(4) and H_(2)SiF_(6),leaching temperatures(40−80℃)and time(15−75 min),were investigated.Moreover,an efficient tubular reactor was employed to improve this acid leaching system.Under the optimal conditions(ore/H_(2)SO_(4)/H_(2)SiF_(6) mass ratio of 1:0.8:1.6,80 wt.% H_(2)SO_(4),15 wt.% H_(2)SiF_(6),80℃,15 min),97.9% of Li,96.4% of K,97.6% of Rb,96.7% of Cs and 81.4% of Al(mass fraction)were leached.Additionally,a two-step thermal process was proposed to remove fluorine of leaching slurry.This acid treatment using an acidic mixture of H_(2)SO_(4) and H_(2)SiF_(6) in a continuous tubular reactor shows potential as an alternative process to extract lithium from lepidolite.
基金Supported by the Natural Science Foundation of the Institutions of Higher Education of Jiangsu (No. 07KJD170012)
文摘To examine spatial variations of grain-size characteristics caused by both natural and human-induced processes along the Lianyungang muddy coast, China, 129 samples were collected and measured using standard sieving and sedimentation techniques. Results show that sediment diameter tends to increase with increasing water depth from nearshore to offshore. Size-frequency distributions indicate a gradual mixing process of coarse and fine diameter material. Grain size trend analysis indicates that a man-made structure, the West has resulted in severe siltation in Haizhou Bay and Breakwater, along with Liandao Island itself, the Lianyungang port area, where sediment quality is also poor. Results demonstrate that grain size can be used as a natural tracer to infer how sediments respond to the effects caused by both natural and human-induced processes.
基金jointly funded by the Science & Technology Pillar Program of Jiangsu Province(BE2011814)the Youth Research Project on Earthquake Trend Tracking of China Earthquake Administration(2014020122)the Key Project of Youth Fund of Earthquake Administration of Jiangsu Province(201402)
文摘In this paper,research is conducted on the characteristics of coda Q values of the Jiangsu area,based on the Aki single backscattering model with the waveforms recorded by the Jiangsu digital seismic network. The results show that the Jiangsu area is a high Q value area as a whole,but the Q value differs obviously between different regions,characterized generally as high in the south and low in the north. This study focuses on 4 sub-regions where the stations are relatively dense,the tectonic features are distinguishing,and the calculation results of coda Q0 are fairly concentrated,and obtains the characteristic relationship between the Q value and frequency of the 4 regions. The region from south Jiangsu to the Yangtze River estuary and that around the Maoshan fault zone are the high Q value areas in Jiangsu; the region from central Jiangsu to the waterfront area is the low Q value area in Jiangsu Province,and the Lianyungang region in northern Jiangsu is the moderate Q value area. Comparing the tectonic activity and seismicity of the 4 different Q value sub-regions,there is a certain correlation between Q value,crustal movement and seismicity.
基金supported by the "the Fundamental Research Funds for the Central Nonprofit Research Institution of CAF",Forest degradation and restoration mechanisms of the alpine mountains from the western China (contract: CAFYBB2014ZD001)
文摘Climate affects Picea crassifolia growth and climate change will lead to changes in the climate–growth relationship(i.e., the "divergence" phenomenon). However, standardization methods can also change the understanding of such a relationship. We tested the stability of this relationship by considering several variables: 1) two periods(1952–1980 and 1981–2009), 2) three elevations(2700, 3000, and 3300 m), and 3) chronologies detrended using cubic splines with two different flexibilities. With increasing elevation, the climatic factor limiting the radial growth of Picea crassifolia shifted from precipitation to temperature. At the elevation of 2700 m, the relationship between radial growth and mean temperature of the previous December changed so that the more flexible spline had a greater precipitation signal. At the elevation of 3000 m, positive correlation of radial growth with mean temperature and precipitation in September of the previous year became more significant. At the elevation of 3300 m, positive correlation between radial growth and precipitation of the currentsummer and the previous spring and autumn was no longer significant, whereas the positive correlation between radial growth and temperature of the current spring and summer strengthened. The detrending with the most flexible spline enhanced the precipitation signal at 2700 m, while that with the least flexible spline enhanced the temperature signal at 3300 m. All results indicated that the divergence phenomenon was affected by the climatic signals in the chronologies and that it was most dependent on the detrending method. This suggests it is necessary to select a suitable spline bootstrap for studies of growth divergence phenomena.
