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ArticleName Research on the technology of high-capacity tantalum capacitor grade powders
ArticleAuthor Orlov V. M., Kolosov V. N., Prohorova T. Yu., Miroshnichenko M. N.

I. V. Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials, Kola Scientific Centre, Russian Academy of Sciences

V. M. Orlov, Head of Laboratory, e-mail:
V. N. Kolosov, Leading Researcher
T. Yu. Prokhorov, Senior Researcher
M. N. Miroshnichenko, Junior Researcher


The processing of electron beam melted and sodiumthermal tantalum capacitor grade powders has been investigated. The technology of electron beam melted agglomerated capacitor grade powders with a charge of 5000–7000 μC/g is described. Its characteristic features are the combination of dehydration and sintering processes, as well as the utilization of hydrogen liberated in the dehydrogenation process with its subsequent use for the hydride. Performed comprehensive studies of the process of sodium-thermal tantalum powders has been investigated showed that the most promising method of obtaining them is to restore from a melt containing potassium heptafluorotantalate (liquid-phase reduction). At the same time methods for diminishing the contents of apparatus impurities in powders and enlarging their surface have been developed. It has been shown that oxygen, added to a tantalate-containing melt at the initial stage of reduction process, promotes the growth of powder particles, including after the addition of new fluorotantalate batches to the melt. The resulting sodiumthermal capacitor powders had a specific charge of 10 000 to 70 000 μC/g.

keywords Tantalum powder, potassium heptafluorotantalate, sodium-thermal reduction, thermal treatment, hydrogenation, dehydrogenation, agglomeration, specific charge, anode, capacitor

1. Mosheim E. T. I. C. bulletin. 2003. N 116. pp. 2–8.
2. Moore J., Prymak J. T. I. C. bulletin. 2004. N 117. pp. 5–8.
3. Poroshok tantala (Tantalum powder). Produktsiya Ulbinskogo metallurgicheskogo zavoda (Production of Ulba metallurgical plant). [Electronnic resources]. Available at:
4. Pozdeev-Freeman Y. T. I. C. bulletin. 2005. No. 122. pp. 4–8.
5. Orlov V. M., Ryungenen T. I., Novichkov V. Yu. Poroshkovaya metallurgiya – Power metallurgy. 1986. No. 11. pp. 27–31.
6. Patent 2284248 RF. Sposob polucheniya poroshka ventilnogo metalla (Method of valve metal obtaining). Orlov V. M., Kolosov V. N., Prokhorova T. Yu., Miroshnichenko M. N. ; asserted 04.04.2005 ; publ. 27.09.2006, Bul. No. 27.
7. Pat. 4356028 US. In situ phosphorus addition to tantalum. Bates V. T. ; publ. 26.10.1982.
8. Pat. 4544403 US. High charge, low leakage tantalum powders. Schiele E. K. et al. ; publ. 01.10.1985.
9. Orlov V. M., Kolosov V. N., Prokhorova T. Yu. et al. Khimicheskaya tekhnologiya — Chemical Technology. 2007. Part. 8, No. 2. pp. 62–65.
10. Kolosov V. N., Orlov V. M., Miroshnichenko M. N. et al. Metally — Metals. 2009. No. 1. pp. 99–104.
11. Pozdeev-Freeman Yu., Rozenberg Yu., Gladkikh A. et al. J. Mat. Science : Mat. Electronics. 1998. Vol. 9. pp. 309–311.
12. Pat. 5605561 US. Tantalum powder and electrolytic capacitor using same. Iwabuchi K. et al. ; publ. 25.02.1997.
13. Appl. 0211932 WO. Method for producing tantalum powder, tantalum powder and tantalum electrolytic capacitor. Mizusaki Yu, Izumi T. ; publ. 14.02.2002.
14. Konstantinov V. I. Elektroliticheskoe poluchenie tantala, niobiya i ikh splavov (Electrolytical obtaining of tantalum, niobium and fheir alloys). Moscow, 1977. 240 p.
15. Pat. 6238456 US. Tantalum powder, method for producing same powder and sintered anodes obtained from it. Wolf R. et al. ; publ. 29.05.2001.

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