An orthogonal array,L16(45),was used to examine the effects of four parameters,including NaCl concentration,H2SO4 concentration,temperature and pulp density,on the recovery of Cu,In,Pb and Zn from a hydrometallurgical...An orthogonal array,L16(45),was used to examine the effects of four parameters,including NaCl concentration,H2SO4 concentration,temperature and pulp density,on the recovery of Cu,In,Pb and Zn from a hydrometallurgical residue via brine leaching.The results show that temperature of leaching solution has a significant effect on the recovery of Cu,In and Zn,while H2SO4 concentration has an obvious influence on these metals extraction.Both pulp density and NaCl concentration significantly affect Pb extraction.Based on the orthogonal array experiments,the optimum conditions for the extraction of Cu,In,Pb and Zn from hydrometallurgical residue are NaCl concentration of 250 g/L,H2SO4 concentration of 1.00 mol/L,temperature of 85℃,and pulp density of 100 g/L.After 1 h of treatment at these optimum conditions,over 91% of the metals are extracted from the residue.Brine leaching is therefore suitable for the recovery of metals from hydrometallurgical residues.展开更多
To investigate the mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions, uniaxial compression test and ultrasonic test were performed. Test results show that the relative dynamic elas...To investigate the mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions, uniaxial compression test and ultrasonic test were performed. Test results show that the relative dynamic elastic modulus, the mass variation,and the compressive strength of cement mortar increase first, and then decrease with increasing erosion time in sodium sulfate and sodium chloride solutions. The relative dynamic elastic moduli and the compressive strengths of cement mortars with water/cement ratios of 0.55 and 0.65 in sodium sulfate solution are lower than those in sodium chloride solution with the same concentration at the420 th day of immersion. The compressive strength of cement mortar with water/cement ratio of 0.65 is more sensitive to strain rate than that with water/cement ratio of 0.55. In addition, the strain-rate sensitivity of compressive strength of cement mortar will increase under attacks of sodium sulfate or sodium chloride solution.展开更多
Using Schiff base as a phase transfer catalyst, ethoxycarbonyl isothiocyanate was synthesized by reacting ethyl chloroformate with sodium thiocyanate. In order to get the best synthetic technology, an orthogonal test ...Using Schiff base as a phase transfer catalyst, ethoxycarbonyl isothiocyanate was synthesized by reacting ethyl chloroformate with sodium thiocyanate. In order to get the best synthetic technology, an orthogonal test （L9（34）） was applied. The results show that reaction temperature, reaction time, content of catalyst and molar ratio of sodium thiocyanate to ethyl chloroformate are the main factors influencing the yield. The four factors chosen for the present investigation are based on the results of a single-factor test. The optimum synthetic technology is determined as follows： reaction temperature 35 ℃, reaction time 3 h, the content of catalyst （molar fraction based on ethyl chloroformate） 1.5% and molar ratio of sodium thiocyanate to ethyl chloroformate 1.1. Under the optimized synthetic technology, the experimental yield reaches 96.8%.展开更多
基金Project(20507022) supported by the National Natural Science Foundation of China
文摘An orthogonal array,L16(45),was used to examine the effects of four parameters,including NaCl concentration,H2SO4 concentration,temperature and pulp density,on the recovery of Cu,In,Pb and Zn from a hydrometallurgical residue via brine leaching.The results show that temperature of leaching solution has a significant effect on the recovery of Cu,In and Zn,while H2SO4 concentration has an obvious influence on these metals extraction.Both pulp density and NaCl concentration significantly affect Pb extraction.Based on the orthogonal array experiments,the optimum conditions for the extraction of Cu,In,Pb and Zn from hydrometallurgical residue are NaCl concentration of 250 g/L,H2SO4 concentration of 1.00 mol/L,temperature of 85℃,and pulp density of 100 g/L.After 1 h of treatment at these optimum conditions,over 91% of the metals are extracted from the residue.Brine leaching is therefore suitable for the recovery of metals from hydrometallurgical residues.
基金Project(LY13E080021) supported by the Natural Science Foundation of Zhejiang Province,ChinaProject(2011A610072) supported by the Ningbo Municipal Natural Science Foundation,ChinaProject(XKL14D2063) supported by Subject Program of Ningbo University,China
文摘To investigate the mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions, uniaxial compression test and ultrasonic test were performed. Test results show that the relative dynamic elastic modulus, the mass variation,and the compressive strength of cement mortar increase first, and then decrease with increasing erosion time in sodium sulfate and sodium chloride solutions. The relative dynamic elastic moduli and the compressive strengths of cement mortars with water/cement ratios of 0.55 and 0.65 in sodium sulfate solution are lower than those in sodium chloride solution with the same concentration at the420 th day of immersion. The compressive strength of cement mortar with water/cement ratio of 0.65 is more sensitive to strain rate than that with water/cement ratio of 0.55. In addition, the strain-rate sensitivity of compressive strength of cement mortar will increase under attacks of sodium sulfate or sodium chloride solution.
基金Project(2007AA06Z122) supported by the National High Technology Research and Development Program of ChinaProject(20110491267) supported by the Postdoctoral Science Foundation of ChinaProject(74341015502) supported by Postdoctoral Fund of Central South University,China
文摘Using Schiff base as a phase transfer catalyst, ethoxycarbonyl isothiocyanate was synthesized by reacting ethyl chloroformate with sodium thiocyanate. In order to get the best synthetic technology, an orthogonal test （L9（34）） was applied. The results show that reaction temperature, reaction time, content of catalyst and molar ratio of sodium thiocyanate to ethyl chloroformate are the main factors influencing the yield. The four factors chosen for the present investigation are based on the results of a single-factor test. The optimum synthetic technology is determined as follows： reaction temperature 35 ℃, reaction time 3 h, the content of catalyst （molar fraction based on ethyl chloroformate） 1.5% and molar ratio of sodium thiocyanate to ethyl chloroformate 1.1. Under the optimized synthetic technology, the experimental yield reaches 96.8%.
