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Kinetics of Mixed Low-Level Waste Incapsulation Using Iron Phosphate Chemically Bonded Cement

Published online by Cambridge University Press:  21 March 2011

A.S. Aloy
Affiliation:
RPA “V.G. Khlopin Radium Institute”, St. Petersburg, RF
T.I. Koltsova
Affiliation:
RPA “V.G. Khlopin Radium Institute”, St. Petersburg, RF
E.N. Kovarskaya
Affiliation:
RPA “V.G. Khlopin Radium Institute”, St. Petersburg, RF
M.Yu. Silin
Affiliation:
RPA “V.G. Khlopin Radium Institute”, St. Petersburg, RF
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Abstract

The iron phosphate cement (IPC) structure formation process has been studied by Mossbauer spectroscopy. The IPC is formed as a result of interaction of iron oxides with orthophosphoric acid and could be used as a matrix for immobilization of low-level radioactive waste.

The structural formation process has been shown may be considered to consist of two stages. The first stage lasts to the moment of setting, when the diffusion process goes on in the liquid phase. At this stage the main fragments of the structural polymeric frame of the IPC are developed consisting of iron (+2) and (+3) phosphates. The rate of the oxides-with-phosphoric-acid reaction as well as the time of hardening depends on the bivalent iron content.

The second stage begins from the moment of setting when the diffusion becomes slower. At this stage the process is characterized by the negligible increase in the iron phosphates (+2), (+3) content and transformation of the previously formed phosphates.

The nuclear gamma-resonance (NGR) parameters have been determined of FeH3(PO4)2·2.5H2O, forming in the hematite (Fe2O3) based IPC: isomeric shift (IS) = 0.46 mm/s, quadrupole splitting (QS) = 0.197 mm/s, FWHM =0.282 mm/s.

Type
Research Article
Copyright
Copyright © Materials Research Society 2006

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References

REFERENCES

1. Wagh, A.S., Jeong, S.Y., Singh, D., Aloy, A.S., Kolytcheva, T.I., Kovarskaya, E.N., Macheret, Yevgeny, “Iron-phosphate-based Chemically Bonded Phosphate Ceramics for Mixed Waste StabilizationTucson, AZ, (Proc. Waste Management, WM '97), 1997, pp. 343349.Google Scholar
2. Aloy, A.S., Kolycheva, T.I., Knecht, D.A., Macheret, Y., “Radiolytic Gas Generation in Chemically-Bonded Iron Phosphate Ceramic Forms Used for Immobilization Plutonium Ash Residues”, Boston, Massachusetts, USA (Mat. Res. Soc. Symp. Proc, MRS'98, 556), 1998, pp.12071274.Google Scholar
3. Aloy, A.S., Kovaskaya, E., Koltsova, T., Macheret, J, Todd, T.A., “Low-Temperature Chemically-Bonded Iron Phosphate Ceramics for Radioactive Waste Management”, Jackson, Wyoming, USA, (Mat. Res. Soc. Symp. International Conference on Future Nuclear Systems, Global'99), 1999.Google Scholar
4. Aloy, A.S., Kovaskaya, E., Koltsova, T., Macheret, J, Todd, T.A., et al, Iron-Phosphate Ceramics for Solidification of Mixed Low-Level Waste US, Patent # 6,075,176, Jun. 13,2000.Google Scholar
5. Kopeikin, V. A., Petrova, A. P., Rashkovan, I. L., “Metal–Phosphate Based Materials”, “Chemistry”, Moscow. (1976), (In Russian).Google Scholar
6. Gerasimov, V. V., Sheptitsky, S. P.. J. Chemistry and Chemical Technology, Vol. 29, No. 7, pp. 8690 (1986).Google Scholar
7. Turkina, L. I., Sudakas, L. G., Paramonova, V. A., Chernikova, A. A.. J. Inorganic Materials, Vol.26, No 9, pp.19671973, (1990).Google Scholar
8. Kingery, W., Fundamental Studies of Phosphate Bonding in Refractories: II. C., J. American Ceramic Society, vol. 33, pp. 242247, (1950).Google Scholar
9. Sychev, M. M., Komlev, V. G.. Proceedings of the Academy of Sciences of the USSR. J. Inorganic Materials, Vol.7, No. 9, pp.16121616, (1971).Google Scholar