Reduction smelting of the bismuth oxide residue from pressure leaching of bismuth sulfide was investigated in the FeO-SiO_2-CaO ternary slag system.The results show that all the recovery ratios of Bi,Ag,Cu and Pb incr...Reduction smelting of the bismuth oxide residue from pressure leaching of bismuth sulfide was investigated in the FeO-SiO_2-CaO ternary slag system.The results show that all the recovery ratios of Bi,Ag,Cu and Pb increase with the increase of reductive coal proportion,reaction temperature and time,while too much reductive coal would help Fe enter metal phase;CaO/SiO_2and Fe O/SiO_2 of the chosen slag system should be 0.5-0.75 and 1.25-1.75,respectively,for the reason that the slag system has the optimum mobility and is beneficial for the recovery of metals.The corresponding optimum conditions are determined as follows:the added coal proportion is 7%of the leaching residue,CaO/SiO_2 mass ratio in the chosen slag system is 0.5 and FeO-SiO_2 is 1.5,the reaction temperature is 1300°C and the reaction time is 40 min.Under the above conditions,the recovery ratios of Bi,Ag,Cu and Pb are 99.6%,99.8%,97.0%and 97.3%,respectively.展开更多
Boric acid and kieserite were prepared from low-grade ascharite by sulfuric acid method.This method results in the recovery of 71.06%and 45.03%for boric acid and kieserite,respectively.Meanwhile,the boric acid was pre...Boric acid and kieserite were prepared from low-grade ascharite by sulfuric acid method.This method results in the recovery of 71.06%and 45.03%for boric acid and kieserite,respectively.Meanwhile,the boric acid was precipitated from the filtrate at low temperature and the solution was recycled without discharging waste liquid in the whole process.The influence of amount of sulfuric acid,mass fraction of sulfuric acid,reaction temperature and reaction time on the leaching rate of boric acid were studied. The results show that the leaching rate of boric acid reaches 93.80%under the following conditions:the amount of sulfuric acid is 85%of theoretical dosage;the mass fraction of sulfuric acid is 25%;reaction temperature is 95℃;and the reaction time is 100 min. Meanwhile,the effects of mass fraction of magnesium sulfate,crystallization temperature and crystallization time on the crystallization of kieserite were investigated and the optimal crystallization conditions are obtained:the mass fraction of magnesium sulfate is 28%;the crystallization temperature is 180℃and the crystallization time is 4h.展开更多
Along with innovation in ICT technology and the spread of the internet,the online network,through its“technological empowerment”of citizens and governments,has driven a series of institutional changes designed to pr...Along with innovation in ICT technology and the spread of the internet,the online network,through its“technological empowerment”of citizens and governments,has driven a series of institutional changes designed to promote government responsiveness.The global spread of online political deliberation is indeed an achievement of the internetdriven construction of responsive government.In recent years,the Chinese government has vigorously promoted online political deliberation,established virtual platforms to build bridges between netizens and public power,brought internet activism into institutional channels,and implemented political absorption and online consultation.Under the influence of policy initiatives and local innovations,China has created diversified response systems that strengthen the institutionalization of online political deliberation and thereby enable this system to play an active role in improving government capacity and regulating the relationship between the state and society.At present,China has seven types of online response:the Communist Party Committee-led mode,the mixed mode,the governmentled mode and the modes led by the departments in charge of absorption,business,supervision departments,and petitioning.Empirical studies show that the diversity and degree of institutionalization of online political deliberation significantly affect institutional performance and that political authority and professionalism are important features that enable the different response systems to influence institutional performance.In short,the endogenous elements of the response system—level of institutionalization and institutional diversity—are key factors in institutional performance.展开更多
Based on the definition of second order moment and the approximate three-dimensional analytical formula for probe detected laser beam passing through a cat-eye optical lens with center shelter and oblique detector, th...Based on the definition of second order moment and the approximate three-dimensional analytical formula for probe detected laser beam passing through a cat-eye optical lens with center shelter and oblique detector, the analytical expression of the encirclement power ratio of the cat-eye effect reflected light under far-field condition has been deduced. Variable laws of light intensity at the return place and encirclement power ratio are performed by numerical calculation, and are analyzed physically. The results show that the light intensity at the return place decreases monotonically with the increases of the diameter, incidence angle, tilted angle of the detector and the center shelter ratio, but the relationships between these parameters and the encirclement power ratio are all nonmonotonic. The reasonable choice of the focal shift size would result in the largest light intensity at the return place and the largest erirclenent power ratio.展开更多
基金Project(134414) supported by the Postdoctoral Funded Program of Central South University,China
文摘Reduction smelting of the bismuth oxide residue from pressure leaching of bismuth sulfide was investigated in the FeO-SiO_2-CaO ternary slag system.The results show that all the recovery ratios of Bi,Ag,Cu and Pb increase with the increase of reductive coal proportion,reaction temperature and time,while too much reductive coal would help Fe enter metal phase;CaO/SiO_2and Fe O/SiO_2 of the chosen slag system should be 0.5-0.75 and 1.25-1.75,respectively,for the reason that the slag system has the optimum mobility and is beneficial for the recovery of metals.The corresponding optimum conditions are determined as follows:the added coal proportion is 7%of the leaching residue,CaO/SiO_2 mass ratio in the chosen slag system is 0.5 and FeO-SiO_2 is 1.5,the reaction temperature is 1300°C and the reaction time is 40 min.Under the above conditions,the recovery ratios of Bi,Ag,Cu and Pb are 99.6%,99.8%,97.0%and 97.3%,respectively.
基金Project(2006AA06Z368) supported by the National High-tech Research and Development Program of China
文摘Boric acid and kieserite were prepared from low-grade ascharite by sulfuric acid method.This method results in the recovery of 71.06%and 45.03%for boric acid and kieserite,respectively.Meanwhile,the boric acid was precipitated from the filtrate at low temperature and the solution was recycled without discharging waste liquid in the whole process.The influence of amount of sulfuric acid,mass fraction of sulfuric acid,reaction temperature and reaction time on the leaching rate of boric acid were studied. The results show that the leaching rate of boric acid reaches 93.80%under the following conditions:the amount of sulfuric acid is 85%of theoretical dosage;the mass fraction of sulfuric acid is 25%;reaction temperature is 95℃;and the reaction time is 100 min. Meanwhile,the effects of mass fraction of magnesium sulfate,crystallization temperature and crystallization time on the crystallization of kieserite were investigated and the optimal crystallization conditions are obtained:the mass fraction of magnesium sulfate is 28%;the crystallization temperature is 180℃and the crystallization time is 4h.
文摘Along with innovation in ICT technology and the spread of the internet,the online network,through its“technological empowerment”of citizens and governments,has driven a series of institutional changes designed to promote government responsiveness.The global spread of online political deliberation is indeed an achievement of the internetdriven construction of responsive government.In recent years,the Chinese government has vigorously promoted online political deliberation,established virtual platforms to build bridges between netizens and public power,brought internet activism into institutional channels,and implemented political absorption and online consultation.Under the influence of policy initiatives and local innovations,China has created diversified response systems that strengthen the institutionalization of online political deliberation and thereby enable this system to play an active role in improving government capacity and regulating the relationship between the state and society.At present,China has seven types of online response:the Communist Party Committee-led mode,the mixed mode,the governmentled mode and the modes led by the departments in charge of absorption,business,supervision departments,and petitioning.Empirical studies show that the diversity and degree of institutionalization of online political deliberation significantly affect institutional performance and that political authority and professionalism are important features that enable the different response systems to influence institutional performance.In short,the endogenous elements of the response system—level of institutionalization and institutional diversity—are key factors in institutional performance.
文摘Based on the definition of second order moment and the approximate three-dimensional analytical formula for probe detected laser beam passing through a cat-eye optical lens with center shelter and oblique detector, the analytical expression of the encirclement power ratio of the cat-eye effect reflected light under far-field condition has been deduced. Variable laws of light intensity at the return place and encirclement power ratio are performed by numerical calculation, and are analyzed physically. The results show that the light intensity at the return place decreases monotonically with the increases of the diameter, incidence angle, tilted angle of the detector and the center shelter ratio, but the relationships between these parameters and the encirclement power ratio are all nonmonotonic. The reasonable choice of the focal shift size would result in the largest light intensity at the return place and the largest erirclenent power ratio.
