Dmitry Sukhomlinov

Thermodynamic stability of solid phases in the system Cu–O–Al2O3 by means of the EMF and DSC-TGA techniques

Thermodynamic properties of solid phases in the Cu–O–Al2O3 system were measured by means of the EMF method with oxygen concentration galvanic cells based on stabilized zirconia solid electrolytes. The standard Gibbs energies of formation of pure copper oxides and copper aluminates from their component oxides were determined. Copper aluminates were also investigated calorimetrically by the DSC-TGA combined techniques. Based on the calorimetric measurements, the enthalpies and temperatures of spinel decomposition and delafossite melting were determined. The obtained results were discussed and compared with the available literature data.

Behavior of Co, Ni and Precious Metals in Copper Converting Process: Experimental Study

This study is focused on distribution of Co, Ni, Ag, Au, and Pd between molten copper and molten copper sulfide (‘white metal’) phases in copper converting conditions. The behavior of the elements selected was studied experimentally at 1300 °C and at various sulfur dioxide partial pressures (0.01, 0.05, 0.1, 0.5, and 1 atm). The experimental technique employed involves a high temperature equilibration followed by rapid quenching in ice water, with subsequent quantitative elemental analysis of the equilibrium phases with an electron micro probe analyzer. The distribution coefficients \( {\text{L}}_{\text{Me}}^{{{\text{Cu}}/{\text{wm}}}} \) determined in this work can be arranged in the following sequence: Co < Ag < Ni < (Au, Pd).

High-temperature oxidation of bismuth- and antimony-based sulfosalts

ABSTRACT In this article, oxidation processes of Ag-Bi-Sb-based phases were investigated. Synthesized AgBiS2 and AgSbS2-Sb2S3-Sb samples were thermally analyzed in synthetic air by applying the simultaneous DSC-TGA analysis technique. The oxidation processes at PO₂=0.2 atm and T<1173 K were observed to take place in many-step sequence of various reactions with an overall reaction 2AgMeS2 + 5.5O2(g) ⇄ 2Ag + Me2O3 + 4SO2(g), where Me=(Bi,Sb). Oxidations of AgBiS2, Sb2S3, and AgSbS2 were observed to begin above 549±2K, 610±2K, and 733±2K, respectively. Furthermore, oxidation processes of AgBi3S5 and Ag3SbS3 were estimated, and thermodynamic functions for the overall oxidation reactions were calculated and discussed.

Thermodynamic Stability of Condensed Phases in the Ternary System CaO–Cu–O by the EMF Method

The standard thermodynamic properties of the compound Ca2CuO3 were determined electrochemically by the Electromotive Force (EMF) method. The ternary phase Ca2CuO3 was synthesized from the pure oxides CaO and CuO at CaO saturation using a ceramic route. The EMF measurements were performed over a temperature range 973 ≤ T/K ≤ 1124. The standard Gibbs energy of formation of the ternary compound Ca2CuO3 was determined using the EMF technique as:

Distributions of lithium-ion and nickel-metal hydride battery elements in copper converting

\Delta _{{{\text{f}}({\text{ox}})}} {\text{G}}^\circ_{\text{Ca2CuO3}} = 2 1. 8 8 4{-} 2 2. 9 2\cdot 10^{ - 3} \cdot {\text{T}}.

Determination of standard thermodynamic properties of Sb2O3 by a solid-oxide electrolyte EMF technique

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