Solvent Extraction of Some Lanthanides with Trioctylphosphine Oxide in Molten Paraffin Wax

The extraction behavior of Ln(III) (Ln=Nd, Sm, Tb and Yb) with trioctylphosphine oxide (TOPO) in molten paraffin wax has been studied. The effect of pH, TOPO concentration, medium, stirring time and the amount of sails added on the distribution of lanthanides between two phases were investigated. Two different compositions Ln(H2O)(t-2) (TOPO)(2)(OH)(2)NO3 (Ln=Nd and Sm) and Ln(H2O)(s-1) (TOPO)(2)(OH)(NO3)(2) (Ln=Tb and Yb) were determined by slope analysis method. The equilibrium extraction constant K-ex and pH(1/2) value were calculated and the thermodynamic parameters were obtained from the dependence of K-ex on the temperature.

Preparation and Characterization of ZrO_2 Nanoparticles Capped by Trioctylphosphine Oxide (TOPO)

Monodisperse ZrO2 nanoparticles capped by trioctylphosphine oxide （TOPO） were prepared in non-aqueous solvent using in-situ synthesis method. Transmission electron microscopy（TEM）, X-ray diffraction（XRD）, X-ray photoelectron spectrometer（XPS）, Fourier transformation infrared spectroscopy （FTIR）, and thermogravimetric analysis（TGA） were adopted to characterize and investigate the size, structure, composition, and the binding manners between organic capping agent TOPO and inorganic ZrO2 nanocores of the as-prepared nanoparticles. In addition, the nanoparticles were also studied to determine their solubility and relative stability. The experimental results show that the prepared nanoparticles contain about 25% organic capping shell TOPO, 75% inorganic ZrO2 nanocores, and can be easily dissolved and be stably disersed in non-polar organic solvents.

Synergistic Extraction of Lanthanides by 1-Nitroso-2-Naphthol and Trioctylphosphine Oxide in Paraffin Wax

The paraffin wax was used as a diluent for 1-nitroso-2-naphthol(HA) and trioctylphosphine oxide(TOPO) in the extraction of lanthanides at 70℃. The composition of the extracted species was given as LnA_3(TOPO)_2 by means of the slope analysis. The variation of the synergistic extraction equilibrium constant(K_ sex) was investigated at 60～80℃, and the thermodynamic data were calculated. The dependence of separation factors on temperature was also studied.

Solvent extraction and stripping of lithium ion from aqueous solution and its application to seawater

For the development of lithium ion recovery process from seawater, a series of experimental researches were performed. Solvent extraction of lithium ion from aqueous solution using kerosene as solvent was proposed. Lithium ion is effectively extracted by thenoyltrifluoroace- tone-trioctylphosphine oxide （TTA-TOPO） in kerosene within 80 min. Extraction efficiency is severely influenced by stoichiometric parameters. Among the stoichiometric parameters, volume ratio of aqueous （A） to extraction （E） solution is the most influential parameter. After extrac- tion, lithium ion could be easily stripped from the extraction solution by acidic solutions. Stripping efficiency decreases with pH of acidic solutions, and the kind of acid does not affect the stripping efficiency. Extraction efficiency main- tains at more than 93 % even when the extraction solution is recycled three times. 65 % of lithium ion can be extracted from seawater by this solvent extraction process when magnesium ion is precipitated by NHaOH prior to solvent extraction process. Other metallic ions in seawater decrease the extraction efficiency of lithium ion.