Activities of oxygen in liquid thallium and indium from electrochemical measurements

Modified coulometric titrations on the galvanic cell;O in liquid Tl or In/ZrO₂(+CaO)/Air, Pt, were performed at 973, 1073, and 1173 K to determine the oxygen activities in liquid thallium and liquid indium. The standard Gibbs energies of solution of oxygen in liquid thallium and liquid indium for l/2 O₂ →O (1 at. pct) were determined respectively to be δG‡(in Tl) = -22000 + 0.74T (±300) cal/g-atom = -92000 + 3.10T (±1300) J/g-atom, δG‡(in In) = -42450+ 3.30T (±350) cal/g-atom = -177600 + 13.8T (±1500) J/g-atom, where the reference state for dissolved oxygen was an infinitely dilute solution. It was reconfirmed that the apparent initial oxygen concentration observed in the range of very low oxygen concentration in liquid metal was attributed to the oxygen released from the solid electrolyte.     

Activities of oxygen in liquid copper and silver from electrochemical measurements

Modified coulometric titrations on the galvanic cell:O in liquid Cu or Ag / ZrO₂( + CaO) / Air, Pt, were performed to determine precisely the oxygen activities in liquid copper and silver in the range of relatively low oxygen concentration. The present experimental results were remarkably reproducible in comparison with the published data. The standard Gibbs energies of solution of oxygen in liquid copper and liquid silver for 1/2 O₂(l atm) → O(l at. pct) were determined respectively to be ΔG° (in Cu) = −18040 −0.03 T(K) (± 120) cal · g-atom−1 = −75500 −0.12 T(K)(± 500) J · g-atom−1, ΔG°(inAg)= -3860+ 1.56 T(K) (±90) cal · g-atom−1 = −16140 + 6.52 T(K)(±380) J · g-atom−1 where the reference state for dissolved oxygen was an infinitely dilute solution. The present value of the partial entropy of oxygen dissolved in liquid copper differs significantly from that suggested by many investigators. Further, the present equation for liquid copper has been found to be consistent with a correlation proposed previously by the present authors. The equation for liquid silver is in good agreement with the published ones.     

Wettability of MgO single crystal by liquid pure Pb,Sn and Bi

The wettability of MgO single crystals by liquid metals such as Sn, Pb and Bi was studied at 873 K in a hydrogen atmosphere. It became apparent that wettability was dependent on a crystallographic orientation and a heat treatment of the MgO substrate. The MgO surfaces were observed using an atomic force microscope (AFM) to clarify the effect of the surface arrangement of the substrate on wettability. The results suggest that the surface arrangement of the substrate does indeed affect wettability.     

The Densities of liquid In−Bi,Sn−In,Bi−Sb,and Bi−Cd−Tl alloys

Metallurgical and Materials Transactions B -     

Thermodynamic measurements in liquid Sn−Ag Alloys

The reversible galvanic cell: $$ Sn(l), SnO_2 (s)/CaO - ZrO_2 /Sn - Ag(1),SnO_2 (s) $$ electrolyte was employed to determine the thermodynamic properties of liquid Sn?Ag Alloys in the range ofX _Sn from 0.2 to 0.9 and in the overall temperature range of 825° to 1111°K. The data are consistent with the phase diagram. At 900°K, tin shows both positive and negative deviations from Raoult’s law, anda _Sn values agree well with the determinations of Frantik and McDonald but not with those of Laurieet al. At 1100°K, both tin and silver exhibit negative deviations from Raoult’s law lines.     

Thermodyn mics of oxygen in liquid tellurium from electrochemical me surements

The activity coefficient of oxygen in liquid tellurium at 753 nd 823 K w s measured by the coulometric titration method employing solid electrolyte. The oxygen was found to obey Henry’s law, and the standard Gibbs energy of solution of oxygen in liquid tellurium for l/2O₂ O (1 t. pct) was determined to be: 1 $$\Delta G^O (inTe ) = ---21,840 + 10.3T (cal/g--atom)$$ 2 $$ = ---91,380 + 43.1T (J/g--atom)$$ . The standard Gibbs energy of formation of TeO₂ was also determined by using similar electrochemical cell; the result is: 3 $$\Delta G^O (TeO_2 ) = - 79,920 + 46.5T(cal/mol)$$ 4 $$ = - 334,400 + 194.6T(J/mol)$$ The solubility of oxygen in liquid tellurium was calculated from the combination of these two results to be: 5 $$C_S = \exp (6.52 - 9119/T)(at.pct )$$ By comparison of the present results for tellurium with the published values for the other elements, thermodyn mic behavior of oxygen dissolved in liquid elements was discussed and compared with sulfur dissolved in liquid elements.     

Activities of oxygen in liquid Cu-Sb and Cu-Ge alloys

In order to determine the activity coefficients of oxygen, γΩ in liquid Cu-Sb and Cu-Ge alloys at 1373 K as a function of alloy composition, the modified coulometric titrations, described previously, have been performed by using the galvanic cell: O in liquid Cu-Sb or Cu-Ge alloys/ZrO₂ (+CaO)/Air, Pt. A pronounced point of inflection in the In γΩvs alloy composition curve has been observed both for Cu-Sb and Cu-Ge alloys, as predicted by Jacob and Alcock’s quasichemical equation. The measured data itself, however, are significantly different from those predicted by their equation. The validity of Wagner’s solution model with one or two energy parameters has been also tested. YOSHIHIRO MATSUMURA, formerly a Graduate Student, Osaka University.     

Activities of oxygen in liquid Bi-Pb and Bi-Sb alloys

The activity coefficient of oxygen, γ_o, in liquid Bi-Pb and Bi-Sb alloys at 1073 K has been measured over the entire composition range utilizing a modified coulometric titration method with the electrochemical cell: O in liquid Bi-Pb or Bi-Sb alloys/ZrO₂(+CaO)/Air, Pt. The measured In y0 values for both systems, plotted in terms of alloy composition, lie on upwardly concave curves. This behavior is significantly different from what is predicted by the quasi-chemical equations. The models of Wagner and of Blanderet al., which involve one adjustable parameter,h, give a satisfactory representation of the data. YOSHIKAZU KUROSE, formerly a Graduate Student, Osaka University, Osaka, 565, Japan     

降低高纯铅中的Cu、Bi、Sn等杂质含量

本文叙述了用电解精炼法在制备高纯铅过程中，降低铜、铋、锡杂质含量的各种措施和试验结果，比较详细地介绍了用硫化法降低电解液中的铜、铋、锡杂质的新工艺。     

Activities of As,Sb, Bi,and Pb in copper mattes

The transportation method was used to determine the activity coefficients of the minor impurity components As, Sb, Bi, and Pb in homogeneous copper mattes (Cu-Fe-S) as functions of the Cu/Fe mole fraction ratio and of the sulfur content of the matte at 1200 °C. All matte samples contained about 0.2 wt pct As, Sb, Bi, and Pb. The activity coefficients were calculated on the basis of primary experimental data and available thermodynamic values of the gas components, which exist over the mattes. The sulfur-to-metal ratio, which controls the activities of the main matte constituents, was found to be the most important factor influencing the activities. When the sulfur-to-metal ratio of the matte changed from sulfur deficit to sulfur excess, the activity coefficient of As varied from 0.52 to 38, Sb from 3.3 to 82, Bi from 75 to 3.4, and Pb from 25 to 0.079 in the matte. The activities of AsS_1.5, AsS, SbS_1.5, BiS_1.5, and PbS had negative deviations from the ideal behavior.     

ICP—AES法测定海绵铁中砷、锡、铅、锑、铋

文章提出了用ICP—AES法直接测定海绵铁As、Sn、Pb、Sb、Bi含量的方法,建立了最佳工作条件。对各元素的分析线进行了选定,考察了干扰情况、介质酸度等对测定结果的影响。方法准确,快速简便,重现性好。