Extraction of Thallium with Butyl Acetate

ABSTRACT

Experimentally obtained extraction isotherms of the system thallium-sulfuric acid-sodium chloride-butyl acetate are presented. The influence of the sulfuric acid and chloride anion concentrations on the extraction equilibria of thallium was investigated. An increase in the acidity of the aqueous phase results in steeper extraction isotherms, and the amount of thallium extracted generally increases. The influence of chloride anions on the equilibrium is more complex. It was found that the extraction equilibria is not influenced by the chloride ion concentration, provided that the Cl/T1 ratio in the aqueous phase is ? 4. If this ratio is less than 4, the concentration of chloride anions significantly influences the extraction isotherms. The results obtained are discussed in terms of the composition of the complex in the organic phase. An apparent reaction constant equation is proposed for the prediction of the extraction equilibria.     

Crystal growth and properties of TI3BX4 crystals for acoustic surface-wave and bulk acoustic devices

Crystals of Tl₃TaS₄ and T1₃Tase₄ possess properties which indicate that they could be extremely useful for acoustic devices. They are piezoelectric, have low acoustic velocities (6.89 to 8.53 x 10₄ cm/sec), high effective values of electromagnetic coupling (k² up to ~ 3%) and contain directions in which the thermal coefficients of delay are zero. Materials preparation and crystal growth and properties are described.     

Asymmetry between flux penetration and flux expulsion in Tl-2212 superconductors

dc magnetic hysteresis as well as flux penetration and flux expulsion were investigated in Tl_2–y Ba₂CaCu₂O_8–x polycrystals and monocrystals. All measurements were performed at 35 K and in the 0–5 T field range. Hysteresis measurements revealed an irreversibility field of about 2 T. Existing models predict identical field-cooled (fc) and zero-field-cooled (zfc) magnetizations and vanishing time dependence above this field. Although the identical fc and zfc magnetizations are in fact observed, the time dependence vanishes only for flux penetration after zero-field cooling; a remanence is preserved after field cooling and decays with a finite relaxation rate. Activation energies calculated on the basis of the thermal activation model display a pronounced field dependence, and arelower for flux penetration than for flux expulsion in high fields (H3 T) for all orientations. This behavior of extreme layered superconductors contradicts classical theoretical models and questions the original definition of the irreversibility line as well. All of our results are consistent with the recent theory of lock-in transition, and can be well interpreted by using those principles.     

土壤溶液中铊存在形式的理论探讨

本文结合土壤以及土壤污染的特点，从理论上探讨了剧毒元素铊在土壤溶液中可能的化学形态，为实际问题的解决提供了理论根据和方法。     

铊矿湿法制取高纯铊的研究

根据贵州铊矿资源的特点，介绍了一种化学法制取高纯铊的生产工艺和应用方法。     

Two-equivalent electrochemical reduction of a cyano-complex [Tl(CN)2] and the novel di-nuclear compound [(CN)5Pt−Tl]

Extending our recent insights in two-electron transfer microscopic mechanisms for a Tl^III/Tl^I redox system [D.E. Khoshtariya, et al., Inorg. Chem. 41 (2002) 1728], the electrochemical response of glassy carbon electrode in acidified solutions of Tl^III (ClO₄)₃ containing different concentrations of sodium cyanide has been extensively studied for the first time by use of cyclic voltammetry and the CVSIM curve simulation PC program. The complex [Tl^III(CN)₂]⁺ has been thoroughly identified electrochemically and shown to display a single well-defined reduction wave (which has no anodic counterpart), ascribed to the two-equivalent process yielding [Tl^I(aq)]⁺. This behavior is similar to that of [Tl^III(aq)]³⁺ ion in the absence of sodium cyanide, disclosed in the previous work, and is compatible with the quasi-simultaneous yet sequential two-electron transfer pattern (with two reduction waves merged in one), implying the rate-determining first electron transfer step (resulting in the formation of a covalently interacting di-thallium complex as a metastable intermediate), and the fast second electron transfer step. Some preliminary studies of the two-equivalent reduction of directly metal-metal bonded stable compound [(CN)₅Pt^II-Tl^III]⁰ has been also performed displaying two reduction waves compatible with a true sequential pattern.     

Electrochemical study of the quasi-binary thallium(I) telluride–indium(III) telluride solid system

The Tl₂Te–In₂Te₃ solid system was studied using emf measurement of concentration cells to verify the phase diagram for the system published earlier by other authors. Partial molar thermodynamic functions of thallium at 443 K were determined for the ternary phases of this system. The study produced substantial evidence corroborating the formation of a new compound not found earlier.     

X-Ray and Neutron Diffraction Studies on Thermal Parameters of Thalous Bromide

Thermal parameters of TIBr were determined using both X-ray and neutron diffraction techniques. The data was analysed by Rietveld profile refinement procedure. From the neutron diffraction data, due to weak odd-order reflections, it was not possible to determine the individual thermal parameters. The X-ray diffraction measurements yielded BT1=0.296(5)nm2 and BBr=0.162(5) nm2. The overall isotropic value, J9 was 0.252(7) nm2 which is in good agreement with B=0.230(8) nm2 obtained from present neutron diffraction measurements. The present values are also in good agreement with theoretical estimates obtained from the shell models.     

铊的生产现状与开发

本文叙述了铊的资源,生产厂家,工业生产现状,用途,并展望其发展前景。     

稀散元素镓铟铊配合物的研究进展

概述了稀散元素镓、铟和铊配合物的研究进展和目前研究动向 .