摘要
The extraction kinetics of Gd（III） from the nitric acid medium using bis（2,4,4-trimethylpentyl） dithio- phosphinic acid （Cyanex301） and 2-ethylhexyl phosphoric acid （D2EHPA） in kerosene solution were measured by the single drop technique. The influences of hydrogen ion concentration, gadolinium ion concentration, extractant concentration, column height, and nozzle diameter on the extraction rate were investigated. The forward rate equations for the gadolinium extraction with D2EHPA and Cyanex301 were obtained. Based on the experimental results, the forward extraction rate constant was calculated. With the increase of D2EHPA or Cyanex301 concentration, the drop rising diameter and the value of interfacial tension decrease in the studied system, which shows that D2EHPA or Cyanex301 has interfacial activity as a kind of surfactant. Also, the droplet diameter and interfacial tension decrease with the increase of aqueous solution acidity. The experimental results show that the D2EHPA extractant provides faster extraction rate in comparison with Cyanex301 extractant, and it would be useful in industrial continuous extraction process.
The extraction kinetics of Gd（III） from the nitric acid medium using bis（2,4,4-trimethylpentyl） dithio- phosphinic acid （Cyanex301） and 2-ethylhexyl phosphoric acid （D2EHPA） in kerosene solution were measured by the single drop technique. The influences of hydrogen ion concentration, gadolinium ion concentration, extractant concentration, column height, and nozzle diameter on the extraction rate were investigated. The forward rate equations for the gadolinium extraction with D2EHPA and Cyanex301 were obtained. Based on the experimental results, the forward extraction rate constant was calculated. With the increase of D2EHPA or Cyanex301 concentration, the drop rising diameter and the value of interfacial tension decrease in the studied system, which shows that D2EHPA or Cyanex301 has interfacial activity as a kind of surfactant. Also, the droplet diameter and interfacial tension decrease with the increase of aqueous solution acidity. The experimental results show that the D2EHPA extractant provides faster extraction rate in comparison with Cyanex301 extractant, and it would be useful in industrial continuous extraction process.
基金
financially supported by the Iran National Science Foundation(INSF)(No.90005452)
