The extraction of neodymium（III） from acidic nitrate medium was investigated using Cyanex 921 as extractant in kerosene. The metal concentration in the aqueous phase before and after extraction was determined spectr...The extraction of neodymium（III） from acidic nitrate medium was investigated using Cyanex 921 as extractant in kerosene. The metal concentration in the aqueous phase before and after extraction was determined spectrophotometrically by Arsenazo III method. The complete equilibration was achieved in 15 rain. The effects of shaking time, nitric acid concentration, nitrate concentration, extractant concen- tration, and temperature on the extraction were studied. The extraction of Nd（III） was found to increase very slowly with increase in concen- tration of HNO3 in the range of 0.001-3.008 mol/L and then decreased when 0.01 mol/L HNO3 was used. The percentage of extraction was increased with increase in nitrate concentration from 0.01M）.45 mol/L and then decreased when nitrate concentration increased to 0.5 mol/L. Quantitative extraction of Nd（III） （98%） was obtained from the aqueous phase containing 0.001 mol/L HNO3 and 0.1 mol/L KNO3 using 0.5 mol/L Cyanex 921. On the basis of slope analysis, the extracted complex in the organic phase was proposed to be Nd（NO3）3.2Cyanex 921. The extraction of Nd（III） was found to increase with increase in concentration of metal ion in the range of 0.0014）.05 mol/L from 0.001 mol/L HNO3 and 0.1 mol/L KNO3 with 0.1 mol/L Cyanex 921. The percentage of extraction of neodymium was found to decrease with in- crease in temperature. From temperature variation studies, the negative value of AH indicated the extraction reaction to be exothermic and the negative value of AS indicated the formation of a stable complex, Almost 100% Nd（III） was recovered from the fully loaded organic phase using 0.002 mol/L H2SO4 and 0.01 mol/L HCl.展开更多
目前针对921A钢材裂纹的检测方法,无法有效利用材料特点得出最优探头参数,从而提高检测精度、在检测过程中有效减少材料损失。文章基于交流电磁场检测技术(alternating current field measurement,ACFM)开发了一种针对921A钢材裂纹的无...目前针对921A钢材裂纹的检测方法,无法有效利用材料特点得出最优探头参数,从而提高检测精度、在检测过程中有效减少材料损失。文章基于交流电磁场检测技术(alternating current field measurement,ACFM)开发了一种针对921A钢材裂纹的无损检测系统并试验研究。通过有限元软件Ansys Maxwell进行模型建立与仿真,并使用曲面响应法(response surface methodology,RSM)得出最优探头电磁组合参数。结合实际,利用单片机设计磁芯激励及功率放大电路、探头检测电路,并编写信号控制软件,使用Matlab设计检测信号采集及数据处理,形成一套完整的检测系统。最后利用不同尺寸的裂纹进行检测。实验结果表明,系统中信号发生器输出电压稳定,且功率放大模块可以降低感抗增强激励效果,可以有效检测出不同裂纹特征,长度误差率为7.325%,深度误差率为9.96%。展开更多
This article reports the extraction of zirconium （IV） from aqueous HC1 solution by tri-octyl amine （TOA）, Cyanex 921, and their binary mixture using kerosene as the diluent. The effect of some parameters on the ex...This article reports the extraction of zirconium （IV） from aqueous HC1 solution by tri-octyl amine （TOA）, Cyanex 921, and their binary mixture using kerosene as the diluent. The effect of some parameters on the extraction of Zr（IV） was investigated such as equilibration time, aqueous phase acidity, extractant molarity, chloride ion concentration, nature of diluents, and temperature. The extraction of Zr（IV） was found to be 99% from 7.5 M HC1 using the mixture of extractants containing 0.1 M TOA and 0.02 M Cyanex 921 in kerosene. Kerosene was found to be the effective diluent for the extraction of Zr（IV） with the binary mixture of TOA and Cyanex 921. The positive enthalpy change and positive entropy change in the binary extraction system show the endothermic process with an increase in entropy. Stripping of Zr（IV） from the loaded organic phase containing the mixture of TOA （0.1 M） and Cyanex 921 （0.02 M） indicates that HNO3 and Na2CO3 are the best stripping agents.展开更多
Hot corrosion behaviors of the 921A alloy and Fe-based amorphous coating induced by KCl-10% ZnCl_(2) and KCl-55% ZnCl_(2) salts at 450℃ in air for 40 h were investigated.Results show that the 921A alloy suffers more ...Hot corrosion behaviors of the 921A alloy and Fe-based amorphous coating induced by KCl-10% ZnCl_(2) and KCl-55% ZnCl_(2) salts at 450℃ in air for 40 h were investigated.Results show that the 921A alloy suffers more serious corrosion damage than the coating and KCl-55% ZnCl_(2) salts are more corrosive than KCl-10% ZnCl_(2) salts.In the two salts,an Fe_(2)O_(3) layer is formed on the 921A alloy surface,while an outer Fe-rich oxide layer and an inner Cr-rich oxide layer are formed on the surface of the coating.Moreover,a certain amount of metal chloride can be found at the oxide/alloy(coating)interface,which can be explained by "active oxidation".However,the corrosion resistance of the Fe-based amorphous coating did not achieve the desired results,probably because the intersplats in the coating serve as corrosion diffusing channels,which facilitate the corrosion damage rate.Nevertheless,the coating is still in amorphous state after hot corrosion exposure.展开更多
The extraction and separation of Cu(Ⅱ)and Fe(Ⅲ)from HCl media using Cyanex 921 in kerosene were investigated.The effect of shaking time,aqueous phase acid concentration,Fe(Ⅲ)/Cu(Ⅱ)concentration,Cyanex 921 concentr...The extraction and separation of Cu(Ⅱ)and Fe(Ⅲ)from HCl media using Cyanex 921 in kerosene were investigated.The effect of shaking time,aqueous phase acid concentration,Fe(Ⅲ)/Cu(Ⅱ)concentration,Cyanex 921 concentration,temperature and aqueous to organic phase ratio on the separation of Cu(Ⅱ)and Fe(Ⅲ)was studied using 0.1 mol/L Cyanex 921 in kerosene.Maximum separation was achieved from 2 mol/L HCl containing 0.001 mol/L Cu(Ⅱ)and 0.005 mol/L Fe(Ⅲ)with 0.1 mol/L Cyanex 921 in kerosene.Feasible separation of copper and iron was also possible from 5 mol/L HCl using 0.02 mol/L Cyanex 921.展开更多
文摘The extraction of neodymium（III） from acidic nitrate medium was investigated using Cyanex 921 as extractant in kerosene. The metal concentration in the aqueous phase before and after extraction was determined spectrophotometrically by Arsenazo III method. The complete equilibration was achieved in 15 rain. The effects of shaking time, nitric acid concentration, nitrate concentration, extractant concen- tration, and temperature on the extraction were studied. The extraction of Nd（III） was found to increase very slowly with increase in concen- tration of HNO3 in the range of 0.001-3.008 mol/L and then decreased when 0.01 mol/L HNO3 was used. The percentage of extraction was increased with increase in nitrate concentration from 0.01M）.45 mol/L and then decreased when nitrate concentration increased to 0.5 mol/L. Quantitative extraction of Nd（III） （98%） was obtained from the aqueous phase containing 0.001 mol/L HNO3 and 0.1 mol/L KNO3 using 0.5 mol/L Cyanex 921. On the basis of slope analysis, the extracted complex in the organic phase was proposed to be Nd（NO3）3.2Cyanex 921. The extraction of Nd（III） was found to increase with increase in concentration of metal ion in the range of 0.0014）.05 mol/L from 0.001 mol/L HNO3 and 0.1 mol/L KNO3 with 0.1 mol/L Cyanex 921. The percentage of extraction of neodymium was found to decrease with in- crease in temperature. From temperature variation studies, the negative value of AH indicated the extraction reaction to be exothermic and the negative value of AS indicated the formation of a stable complex, Almost 100% Nd（III） was recovered from the fully loaded organic phase using 0.002 mol/L H2SO4 and 0.01 mol/L HCl.
文摘目前针对921A钢材裂纹的检测方法,无法有效利用材料特点得出最优探头参数,从而提高检测精度、在检测过程中有效减少材料损失。文章基于交流电磁场检测技术(alternating current field measurement,ACFM)开发了一种针对921A钢材裂纹的无损检测系统并试验研究。通过有限元软件Ansys Maxwell进行模型建立与仿真,并使用曲面响应法(response surface methodology,RSM)得出最优探头电磁组合参数。结合实际,利用单片机设计磁芯激励及功率放大电路、探头检测电路,并编写信号控制软件,使用Matlab设计检测信号采集及数据处理,形成一套完整的检测系统。最后利用不同尺寸的裂纹进行检测。实验结果表明,系统中信号发生器输出电压稳定,且功率放大模块可以降低感抗增强激励效果,可以有效检测出不同裂纹特征,长度误差率为7.325%,深度误差率为9.96%。
文摘This article reports the extraction of zirconium （IV） from aqueous HC1 solution by tri-octyl amine （TOA）, Cyanex 921, and their binary mixture using kerosene as the diluent. The effect of some parameters on the extraction of Zr（IV） was investigated such as equilibration time, aqueous phase acidity, extractant molarity, chloride ion concentration, nature of diluents, and temperature. The extraction of Zr（IV） was found to be 99% from 7.5 M HC1 using the mixture of extractants containing 0.1 M TOA and 0.02 M Cyanex 921 in kerosene. Kerosene was found to be the effective diluent for the extraction of Zr（IV） with the binary mixture of TOA and Cyanex 921. The positive enthalpy change and positive entropy change in the binary extraction system show the endothermic process with an increase in entropy. Stripping of Zr（IV） from the loaded organic phase containing the mixture of TOA （0.1 M） and Cyanex 921 （0.02 M） indicates that HNO3 and Na2CO3 are the best stripping agents.
基金supported by GuangDong Basic and Applied Basic Research Foundation(No.2020A1515110128).
文摘Hot corrosion behaviors of the 921A alloy and Fe-based amorphous coating induced by KCl-10% ZnCl_(2) and KCl-55% ZnCl_(2) salts at 450℃ in air for 40 h were investigated.Results show that the 921A alloy suffers more serious corrosion damage than the coating and KCl-55% ZnCl_(2) salts are more corrosive than KCl-10% ZnCl_(2) salts.In the two salts,an Fe_(2)O_(3) layer is formed on the 921A alloy surface,while an outer Fe-rich oxide layer and an inner Cr-rich oxide layer are formed on the surface of the coating.Moreover,a certain amount of metal chloride can be found at the oxide/alloy(coating)interface,which can be explained by "active oxidation".However,the corrosion resistance of the Fe-based amorphous coating did not achieve the desired results,probably because the intersplats in the coating serve as corrosion diffusing channels,which facilitate the corrosion damage rate.Nevertheless,the coating is still in amorphous state after hot corrosion exposure.
文摘The extraction and separation of Cu(Ⅱ)and Fe(Ⅲ)from HCl media using Cyanex 921 in kerosene were investigated.The effect of shaking time,aqueous phase acid concentration,Fe(Ⅲ)/Cu(Ⅱ)concentration,Cyanex 921 concentration,temperature and aqueous to organic phase ratio on the separation of Cu(Ⅱ)and Fe(Ⅲ)was studied using 0.1 mol/L Cyanex 921 in kerosene.Maximum separation was achieved from 2 mol/L HCl containing 0.001 mol/L Cu(Ⅱ)and 0.005 mol/L Fe(Ⅲ)with 0.1 mol/L Cyanex 921 in kerosene.Feasible separation of copper and iron was also possible from 5 mol/L HCl using 0.02 mol/L Cyanex 921.
