On the Thermal Decomposition Rate of Molybdenum Sesquisulphide (Mo<SUB>2</SUB>S<SUB>3</SUB>) in Vacuum

• Maru Yôichi

  Department of Metallurgy, Kyoto University

• Yoshida Hiroshi

  Department of Metallurgy, Kyoto University

• Kondô Yoshio

  Department of Metallurgy, Kyoto University

抄録

Kinetics of the vacuum thermal decomposition of Mo₂S₃ pellet into metallic Mo was studied. This reaction plays an important role in the direct winning process of metallic Mo by thermal decomposition of MoS₂. Isothermal weight loss measurement was carried out with 0.5 g, 0.4 g and 0.3 g disc-shaped pellets at 1140°∼1440°C. The pressure within the reaction tube was kept at about 5×10⁻⁵ mmHg.<BR>Concerning the rate-determining step of the reaction, a heat transfer model and a mass transfer model were examined.<BR>The heat transfer model assumes that the heat transfer rate from surroundings to the decomposing interface determines the overall rate. This model was not accepted because a linear rate equation from this model could not explain the parabolic relationship between the decomposition fraction and the time. The mass transfer model assumes that the outward diffusion of sulphur gas through porous Mo shell controls the overall rate. Based on this model, the parabolic kinetic expression was obtained which can explain the experimental results. The change of the rate constant with the pellet thickness can also be explained. The effective diffusivity of sulphur gas was estimated at 1 to 3 cm²/sec.

収録刊行物

• Transactions of the Japan Institute of Metals

  Transactions of the Japan Institute of Metals 10 (1), 8-11, 1969

  社団法人 日本金属学会

キーワード

• General Engineering

詳細情報

• CRID: 1390001205118616704
• NII論文ID: 130003484944
• DOI: 10.2320/matertrans1960.10.8
• COI: 1:CAS:528:DyaF1MXktVGlsb4%3D
• ISSN: 24324701
• ISSN: 00214434
• Web Site: https://www.jstage.jst.go.jp/article/matertrans1960/10/1/10_1_8/_pdf
• 本文言語コード: en
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