Electronically mediated reactions in metal thermal reduction of molybdenum and tungsten oxide compounds
- Authors: Kolosov V.N.1, Orlov V.M.1
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Affiliations:
- Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials Kola Science Centre of the Russian Academy of Sciences
- Issue: Vol 484, No 4 (2019)
- Pages: 447-450
- Section: Physical chemistry
- URL: https://journals.eco-vector.com/0869-5652/article/view/12556
- DOI: https://doi.org/10.31857/S0869-56524844447-450
- ID: 12556
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Abstract
The reduction of tungsten and molybdenum oxide compounds (WO3, MoO3, MgWO4, MgMoO4, and CaMoO4) with calcium vapor at 800–860°С and a residual argon pressure of 5–10 kPa in reactor have been studied. As previously during the reduction with magnesium vapor, the spatial separation of the reaction products was observed, namely, the major portion of the calcium oxide formed in the reaction was deposited outside the reaction zone. A specific feature of the reduction of MgWO4 and MgMoO4 is that the magnesium is first replaced by calcium. The resulting magnesium metal acts as a reducing agent, and the magnesium oxide, along with calcium oxide, forms a crust on the surface of the reaction mass. Analysis of the results shows that the reduction of oxide compounds with magnesium and calcium vapors at a residual argon pressure in reactor of more than 5 kPa proceeds via the electronically mediated reaction mechanism without direct physical contact between the reactants.
About the authors
V. N. Kolosov
Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials Kola Science Centre of the Russian Academy of Sciences
Author for correspondence.
Email: tantal@chemy.kolasc.net.ru
Russian Federation, 14, Fersman street, Apatity, Murmansk region,184209
V. M. Orlov
Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials Kola Science Centre of the Russian Academy of Sciences
Email: tantal@chemy.kolasc.net.ru
Russian Federation, 14, Fersman street, Apatity, Murmansk region,184209
References
- Okabe T.H., Sadoway D.R. // J. Materials Res. 1998. V. 13. № 12. P. 3372–3377.
- Park I., Okabe T.H., Waseda J. // J. Alloys and Compounds. 1998. V. 280. № 1/2. P. 265–272.
- Park I., Okabe T.H., Lee O.Y., Lee Ch.Y., Waseda J. // Materials Trans. 2002. V. 43. № 8. P. 2080–2086.
- Okabe T.H., Park I., Waseda J.Y. // J. Alloys and Compounds. 1999. V. 288. № 1/2. P. 200–210.
- Yoon J.S., Kim B.I. // Metals and Materials Intern. 2007. V. 13. № 2. P. 177–184.
- Рощин В.Е., Рощин А.В. // Металлы. 2013. № 2. С. 12–30.
- Орлов В.М., Колосов В.Н. // ДАН. 2016. Т. 468. № 3. С. 288–292.
- Müller R., Bobeth M., Brumm H., et al. // Int. J. Materials Res. 2007. V. 98. № 11. P. 1138–1145.
- Орлов В.М., Крыжанов М.В., Калинников В.Т. // ДАН. 2015. Т. 465. № 2. С. 182–185.
- Орлов В.М., Крыжанов М.В., Князева А.И. // Физикохимия поверхности и защита материалов. 2016. Т. 52. № 5. С. 500–504.
- Колосов В.Н., Мирошниченко М.Н., Орлов В.М. // Неорган. материалы. 2016. Т. 52. № 8. С. 845–852.
- Орлов В.М., Крыжанов М.В., Калинников В.Т. // ДАН. 2014. Т. 457. № 5. С. 555–558.
- Конышева Е.Ю., Нейман А.Я. // Электрохимия. 2002. Т. 38. № 4. С. 419–427.
- Кофстад П. Отклонение от стехиометрии, диффузия и электропроводность в простых оксидах металлов. М.: Мир, 1975. 336 с.