"A hydrogen reduction technique was used to determine some thermodynamic properties of various zirconium sulfide phases. The equilibrium H2S/H2 ratios were determined as a function of temperature and composition of the condensed sulfide phases. The hydrogen sulfide content of the equilibrated gas mixtures was analyzed by an iodimetric titration procedure.
A detailed description is given for the method and apparatus used both in the preparation of the various sulfide phases and in their equilibration with a hydrogen-hydrogen sulfide gas mixture.
The composition ranger 59 to 67 atomic per cent sulfur was studied over a temperature range of 500⁰ C to 900⁰ C. Within this composition range there existed a two phase region of the Zr3S4 and ZrS2 type phases. The upper limit of this two phase region was bounded by a disulfide phase of a composition which was practically constant over the temperature range investigated. The lower limit of this two phase region was bounded by a Zr3S4 phase composition which varied appreciably with temperature. The upper limit of the disulfide phase solid solution was not definitely determined, but appears to be bounded very closely by the stoichiometric composition of ZrS2. The lower limit of the Zr3S4 phase solid solution was not determined due to the extremely low values of the equilibrium H2S/H2 ratio.
The partial molar free energy, partial molar enthalpy, and partial molarl entropy of solution of sulfur were calculated for various compositions existing in the solid solution regions. A two term free energy equation was calculated for the two phase region of the Zr3S4 type phases. The standard free energy of formation of the zirconium sulfide phases in the composition range 59 to 73 atomic per cent sulfur was determined from unpublished zirconium oxide-sulfide equilibrium data and published data for the ZrS3-ZrS2 equilibrium by means of a graphical method for a temperature of 900⁰ C"--Abstract.
Schlechten, A. W.
Materials Science and Engineering
Ph. D. in Metallurgical Engineering
Union Carbide and Carbon Corporation
Missouri School of Mines and Metallurgy
vi, 112 pages
© 1959 Andrew Hessler Larson, All rights reserved.
Dissertation - Open Access
Library of Congress Subject Headings
Zirconium -- Metallurgy
Sulfides -- Metallurgy
Zirconium compounds -- Thermal properties
Print OCLC #
Electronic OCLC #
Link to Catalog Record
Larson, Andrew Hessler, "A thermodynamic study of the zirconium sulfides" (1959). Doctoral Dissertations. 973.