Solvent extraction of tellurium from chloride solutions using tri-n-butyl phosphate: conditions and thermodynamic data.
The extractive separation of tellurium (IV) from hydrochloric acid media with tri-n-butyl phosphate (TBP) in kerosene was investigated. The dependence on the extraction of tellurium species, concentrations of tellurium and TBP, extraction time and stage, organic/aqueous ratio, and interferences from coexist metallic ions were examined and are discussed. Besides, the stripping agent and stripping time were also studied. It was found that the extraction reaction corresponds to the neutral complex formation mechanism and the extracted species is TeCl4 · 3TBP and that the extraction process is exothermic. The thermodynamic parameters of enthalpy (ΔH), entropy (ΔS), and free energy (ΔG) of the extraction process were evaluated at -26.2 kJ · mol(-1), -65.6 J · mol(-1) · K(-1), and -7.0 kJ · mol(-1), respectively at 293 K.
Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin 300457, China ; Engineering Research Center of Seawater Utilization Technology, Ministry of Education, Hebei University of Technology, Tianjin 300130, China.
Dongchan
D
Li
Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin 300457, China.
Yafei
Y
Guo
Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin 300457, China ; Department of Chemistry & Biochemistry, Laurentian University, Sudbury, ON, Canada P3E 2C6.
Tianlong
T
Deng
Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin 300457, China ; Department of Chemistry & Biochemistry, Laurentian University, Sudbury, ON, Canada P3E 2C6.
Yu-Wei
YW
Chen
Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin University of Science and Technology, Tianjin 300457, China ; Department of Chemistry & Biochemistry, Laurentian University, Sudbury, ON, Canada P3E 2C6.
Nelson
0000-0001-6372-6341
N
Belzile
D002712:Chlorides / Q000032:analysis*; D059625:Liquid-Liquid Extraction / Q000379:methods*; D010755:Organophosphates / Q000737:chemistry*; D012996:Solutions / Q000032:analysis; D012997:Solvents / Q000032:analysis*; D013691:Tellurium / Q000032:analysis*; D013816:Thermodynamics
D002712:Chlorides; D010755:Organophosphates; D012996:Solutions; D012997:Solvents; C009524:tributyl phosphate; D013691:Tellurium