Author: Edward G. KingPublisher:
ISBN:
Category : Molybdenum compounds
Languages : en
Pages : 38
Book Description
Thermodynamics of Some Oxides of Molybdenum and Tungsten
Author: Edward G. KingPublisher:
ISBN:
Category : Molybdenum compounds
Languages : en
Pages : 38
Book Description
Some Reactions of Tungsten (VI) Oxide and Molybdenum(VI) Oxide with Liquid Sulfur
Author: John W. GoodrumPublisher:
ISBN:
Category : Chemical reactions
Languages : en
Pages : 40
Book Description
In situ generation of species for crystal growth in solution is a relatively undeveloped, but promising technique for preparation of solid state material. In this work a solvent, liquid sulfur, generates species in solution by chemical reduction at high temperatures. Evaluation of this high temperature reduction agent included measurements of qualitative and kinetic parameters for the reactions molybdic oxide - sulfur and tungstic oxide - sulfur as a function of temperature, time, and atmosphere. Temperature effects on reduction rate over the range 125 to 400C were markedly non-linear. Reduction products isolated include Mo(IV) oxide at 250C; Mo(IV) sulfide at 400C; W(IV) sulfide at 400C. The oxidation product detected whenever reduced species were found was sulfur(IV) oxide. Additional evidence of species WO(x)S(y) and polymeric sulfur was found. Results of this study indicate that liquid sulfur can serve as a straightforward reducing agent at high temperatures. The rate or extent of such reduction is easily controlled by varying thermal conditions or duration of reaction, and the products of such reductions may be readily isolated by solution techniques which remove unreacted sulfur.
Oxidation of Tungsten
Author: Vincent David BarthPublisher:
ISBN:
Category : Tungsten
Languages : en
Pages : 192
Book Description
The report presents a detailed review of available information on the oxidation of W and its alloys. W is relatively inert below 700 C. As the temperature is increased above this level, however, oxidation becomes progressively more rapid, reaching catastrophic rates at temperatures around 1200 C and above. Various theories for the mechanism and rates of W oxidation at different temperatures are reviewed, and the effect of pressure and water vapor on the stability of W oxides is discussed in detail. The elevatedtemperature reactions of W with other materials, such as refractory oxides, and with gases other than oxygen also are covered. Information on the protection of W by alloying and coating is included. (Author).
Preliminary Report on the Thermodynamic Properties of Selected Light-element and Some Related Compounds
Author: Preliminary Report on the Thermodynamic Properties of Selected Light-element and Some Related Compounds
Author: United States. National Bureau of StandardsPublisher:
ISBN:
Category : Chemistry, Physical and theoretical
Languages : en
Pages : 288
Book Description
"Abstract" signed: Thomas B. Douglas, project leader.
Report of Investigations
Author: Thermodynamic Properties of Minerals and Related Substances at 298.150 K (25.00 C) and One Atmosphere (1.013 Bars) Pressure and at Higher Temperatures
Author: Richard A. RobiePublisher:
ISBN:
Category : Mineralogy
Languages : en
Pages : 590
Book Description
Some Reactions of Tungsten(VI) Oxide and Molybdenum(VI) Oxide with Liquid Sulfur
Author: John Wesley GoodrumPublisher:
ISBN:
Category : Chemical reactions
Languages : en
Pages : 0
Book Description
In situ generation of species for crystal growth in solution is a relatively undeveloped, but promising technique for preparation of solid state material. In this work a solvent, liquid sulfur, generates species in solution by chemical reduction at high temperatures. Evaluation of this high temperature reduction agent included measurements of qualitative and kinetic parameters for the reactions molybdic oxide - sulfur and tungstic oxide - sulfur as a function of temperature, time, and atmosphere. Temperature effects on reduction rate over the range 125 to 400C were markedly non-linear. Reduction products isolated include Mo(IV) oxide at 250C; Mo(IV) sulfide at 400C; W(IV) sulfide at 400C. The oxidation product detected whenever reduced species were found was sulfur(IV) oxide. Additional evidence of species WO(x)S(y) and polymeric sulfur was found. Results of this study indicate that liquid sulfur can serve as a straightforward reducing agent at high temperatures. The rate or extent of such reduction is easily controlled by varying thermal conditions or duration of reaction, and the products of such reductions may be readily isolated by solution techniques which remove unreacted sulfur.
Thermodynamic Properties of Minerals and Related Substances at 298.15° K (25.0° C) and One Atmosphere (1.013 Bars) Pressure and at Higher Temperatures
Author: Richard A. RobiePublisher:
ISBN:
Category : Mineralogy
Languages : en
Pages : 264
Book Description
A summary of the thermodynamic data for minerals at 298.15°K together with calculated values of the functions [...]H0f,T, [...]G0f,T, S0T, and -(G0T - H0298.5/T) at temperatures up to 2,000° K.
Author: