Thermodynamics of oxide sulfate melts: The system PbO PbSO4

Jacob, KT and Toguri, JM (1978) Thermodynamics of oxide sulfate melts: The system PbO PbSO4. In: Metallurgical and Materials Transactions B, 9 (3). pp. 301-306.

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Abstract

Activities in the PbO-PbSO4 melts at 1253 K have been measured by emf and gas-equilibration techniques. The activity of PbO was directly obtained from the emf of the solid oxide cell, Pt, Ni-NiO/CaO-ZrO2/Auo.92PbO.08, PbOx-PbSO4(1-x), Ir, Pt for 1.0 >XPbO > 0.6. The melt and the alloy were contained in closed zirconia crucibles. Since the partial pressure of SO2 gas in equilibrium with the melt and alloy was appreciable (>0.08 atm) atXPbO < 0.6, activities at lower PbO concentrations were derived from measurements of the weight gain of pure PbO under controlled gas streans of Ar + SO2 + O2. The partial and integral free energies of mixing at 1253 K were calculated and found to fit a subregular model: ΔGEPbO =X2PbSO4 {-42,450 + 20,000X2PbSO4} J mol-1 ΔGEPbO =X2pbSO {-12,450 - 20,000XPbS} J mol-1 ΔGEpbSOXPbSO4 {-32,450XPbS - 22,450XPbSO4 } J mol-1. The standard free energy of formation of liquid PbSO4 from pure liquid PbO and gaseous SO3 at 1 atm at 1253 K was evaluated as -88.02 (±0.72) kJ mol-1.

Item Type:	Journal Article
Publication:	Metallurgical and Materials Transactions B
Publisher:	Springer-Verlag
Additional Information:	Copyright of this article belongs to Springer-Verlag.
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	01 Dec 2011 07:39
Last Modified:	01 Dec 2011 07:39
URI:	http://eprints.iisc.ac.in/id/eprint/42499

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