Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-25T18:03:09.298Z Has data issue: false hasContentIssue false

Graphite Processing With Carbon Retention in a Waste Form

Published online by Cambridge University Press:  10 February 2011

M.I. Ojovan
Affiliation:
Scientific and Industrial Association “Radon”, 7th Rostovsky Lane, 2/14, Moscow, 119121, Russia, [email protected]
O.K. Karlina
Affiliation:
Scientific and Industrial Association “Radon”, 7th Rostovsky Lane, 2/14, Moscow, 119121, Russia
V.L. Klimov
Affiliation:
Scientific and Industrial Association “Radon”, 7th Rostovsky Lane, 2/14, Moscow, 119121, Russia
G.Yu. Pavlova
Affiliation:
Scientific and Industrial Association “Radon”, 7th Rostovsky Lane, 2/14, Moscow, 119121, Russia
Get access

Abstract

Conversion of waste graphite into a stable waste form acceptable for long term storage and disposal was considered both theoretically and experimentally. A self-sustaining transformation process of graphite composited with suitable precursors was studied. The powdered precursors that were used were used were: Al+SiO2 (1), Al+TiO2 (2) and Ti+SiO2 (3).

Numeric thermodynamic simulation was performed. Equilibrium temperatures and chemical compositions of reaction products were determined for a wide range of component ratios in the source mixtures. The highest temperatures (up to 2300 K) were observed for precursor type (2). Precursor type (3) demonstrated a minimal rise of temperature of up to 1900 K.

Regions of compositions with complete binding of all chemical elements as well as production of stable final products were found to be rather narrow. About 10 – 13 wt.% of carbon can be processed in composition with given precursors. The gas phase reaction products were studied to minimize carry over of radionuclides. Carbon monoxide was shown to be the main component of the gas phase.

The self-sustaining synthesis process was conducted in ceramic crucibles at ambient pressure in an air atmosphere. Batch masses ranged between 0.1 – 1 kg. Best results were obtained for processing of graphite composited with Al and TiO2. XRD analysis has identified titanium carbide and corundum in the waste form produced. These experiments confirmed that carbon can be converted completely into a stable waste form.

Type
Research Article
Copyright
Copyright © Materials Research Society 2000

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1 Bulanenko, V.I., Frolov, V.V., Nikolayev, A.G., Atomic Energy. 81, 304 (1996) (in Russ.)Google Scholar
2 Natanzon, Ya.V., Tokarevski, V.V., Kremnev, V.A., Petrishchev, V.Ya., and Titov, V.P., SU Patent No. 1 718 277 (31 May 1989).Google Scholar
3 Rudisill, T.S., Merra, J.C., and Peeler, D.K. in Abstracts of the Materials Research Society 1998 Fall Meeting (Boston, Massachusetts, 1998) pp.714715.Google Scholar
4 Merzhanov, A.G., Borovinskaya, I.P., Mahonin, N.S. et al. , Russ. Patent No. 2 065 220 (18 March 1994).Google Scholar
5 Konovalov, E.Ye., Starkov, O.V., Muishkovski, M.P., Gudkov, L.S., and Lisitsa, F.D., Atomic Energy. 84, 239 (1998) (in Russ.).Google Scholar
6 Kropochev, V.V., Ojovan, M.I., Sobolev, I.A. in Proceedings of the 1997 Intern. Conf on Incineration and Thermal Treatment Technologies (Oakland, California, 1997) pp. 207212.Google Scholar
7 Sobolev, I.A., Ojovan, M.I., Petrov, G.A., Klimov, V.L., and Tarasov, V.L. in Proceedings of the 1998 Intern. Conf. on Incineration and Thermal Treatment Technologies (Salt Lake City, Utah, 1998) pp.311313.Google Scholar
8 Trusov, B.G., Simulation of Chemical and Phase Equilibrium at High Temperatures: Computer Code, State Reg. No. 920 054 (31 March 1992).Google Scholar
9 JANAF Thermochemical Tables, J. of Phys. and Chem. Ref. Data, 14, Suppl. No.1 (1985).Google Scholar
10 Gurvich, L.V., Veits, I.V., Medvedev, V.A. et al. , Thermodynamic Properties of Individual Substances, 4th ed. Vol.1–4. (Hemisphere Publ. Corp. & CRC Press, New York, 1989-1994).Google Scholar
11 Klimov, V.L., Ojovan, M.I., Karlina, O.K., and Pavlova, G.Yu. in Proceedings of the 1999 Intern. Conf on Incineration and Thermal Treatment Technologies (Orlando, Florida, 1999).Google Scholar