비등온 열중량법에 의한 AUC분말의 열분해 특성해석

김응호; 김연구; 우문식; 박진호; 유재형; 최청송

HWAHAK KONGHAK, Vol.37, No.1, 14-20, February, 1999

Export Citation

비등온 열중량법에 의한 AUC분말의 열분해 특성해석

Thermal Decomposition Characteristics of AUC Powder by Non-Isothermal Method

김응호, 김연구, 우문식, 박진호, 유재형, 최청송

초록

AUC(ammonium uranylcarbonate) 분말의 배소·환원에 대한 연구를 수소분위기에서 TG-DTA를 사용하여 수행하였다. AUC 분말의 열분해 과정 중 다양한 상 변화 특성을 XRD로 확인하였다. AUC 분말의 열분해 반응 메카니즘은
(NH₄)₄[UO₂(CO₃)₃]→UO₃+3CO₂+4NH₃+2H₂O
3UO₃+H₂→U₃O₈+H₂O
U₃O₈+H₂→3UO₂+H₂O
와 같은 3단계로 나타났다. AUC 분말의 배소·환원 속도는 비등온 열중량법으로 구하였으며, 데이터해석은 Osawa 방법과 Zsako 방법으로 구하였는데 다음과 같다.

Reaction	Mechanusm	E(Kcal/mole)
AUC→UO₃	2^nd nucleation and growth	19.5
UO₃→U₃O₈	3^nd nucleation and growth	30.12
U₃O₈→UO₂	4^th nucleation and growth	31.43

Calcination and reduction of AUC(ammonium uranylcarbonate) have been carried out by using TG-DTA in H₂ atmosphere. Phases of various intermediates obtained during thermal analysis of AUC were confirmed by XRD. As results, AUC was calcined and reduced by three steps as follows;
(NH₄)₄[UO₂(CO₃)₃]→UO₃+3CO₂+4NH₃+2H₂O
3UO₃+H₂→U₃O₈+H₂O
U₃O₈+H₂→3UO₂+H₂O
The calcination and reduction kinetics of AUC have been also determined by non-isothermal method and the analysis of kinetic data was made by Osawa and Zsako methods. The results were as follows;

Reaction	Mechanusm	E(Kcal/mole)
AUC→UO₃	2^nd nucleation and growth	19.5
UO₃→U₃O₈	3^nd nucleation and growth	30.12
U₃O₈→UO₂	4^th nucleation and growth	31.43

Keywords:Ammonium Uranylcarbonate;Calcination;Reduction;Non-Isothermal Method;Hydrogen Atmosphere

[References]

원자력 장기발전 종합계획(2차 시안), 과학기술처 (1990)
Wacklington JS, Raven LF, Thorpe, Br. Nucl. Energy Soc., 18, 283 (1979)
Kim BK, Chang IS, Hwang ST, Park JH, Kim EH, Park JJ, Choi CS, Chem. Ind. Technol., 9, 373 (1991)
Assmann H, Doerr W, "Ceramic Powders," Material Science Monographs 16, Elsevier, 707 (1983)
Assmann H, Bairiot H, IAEA Tech. Report Ser., No. 221, 149 (1983)
Chang IS, Proceedings of the 2nd Korea-Japan Symposium on Separation Technology, Seoul, 519 (1990)
Halldahl L, Nygrem M, J. Nucl. Mater., 138, 99 (1986)
Corfunke EHP, "The Chemistry of Uranium," Elsevier Pub. Co. (1969)
Friedman HL, Polym. Lett., 7, 41 (1969)
Freeman ES, Carroll B, J. Phys. Chem., 62, 394 (1958)
Doyle CD, J. Appl. Polym. Sci., 15, 285 (1961)
Zsako J, J. Phys. Chem., 72(7), 2406 (1968)
Ozawa T, Bull. Chem. Soc. Jpn., 38, 1881 (1965)
Ge Q, Kang S, Thermochim. Acta, 116, 71 (1987)
Kim EH, Park JJ, Park JH, Chang IS, Choi CS, Kim SD, J. Nucl. Mater., 209, 294 (1994)
Halldahl L, Toft Sorensen O, Proc. 6th Int. Conf. on Thermal Analysis, Bayrath, Germany, 499 (1980)
Notz, Mendel, J. Inorg. Nucl. Chem., 14, 55 (1960)
DeMarco, Mendel, J. Phys. Chem., 64, 132 (1960)
Sheila A, Trans. Faraday Soc., 57, 1400 (1961)
Dell, Wheeler, Trans. Faraday Soc., 58, 485 (1962)
Le Page, France, J. Inorg. Nucl. Chem., 36, 87 (1974)
Tompkims FC, "Treatise on Solid State Chemistry," ed. N.B. Hannay, Plenum Press, New York, 4 (1983)

[Referenced By]

[1] 원자력 장기발전 종합계획(2차 시안), 과학기술처 (1990)

[2] Wacklington JS, Raven LF, Thorpe, Br. Nucl. Energy Soc., 18, 283 (1979)

[3] Kim BK, Chang IS, Hwang ST, Park JH, Kim EH, Park JJ, Choi CS, Chem. Ind. Technol., 9, 373 (1991)

[4] Assmann H, Doerr W, "Ceramic Powders," Material Science Monographs 16, Elsevier, 707 (1983)

[5] Assmann H, Bairiot H, IAEA Tech. Report Ser., No. 221, 149 (1983)

[6] Chang IS, Proceedings of the 2nd Korea-Japan Symposium on Separation Technology, Seoul, 519 (1990)

[7] Halldahl L, Nygrem M, J. Nucl. Mater., 138, 99 (1986)

[8] Corfunke EHP, "The Chemistry of Uranium," Elsevier Pub. Co. (1969)

[9] Friedman HL, Polym. Lett., 7, 41 (1969)

[10] Freeman ES, Carroll B, J. Phys. Chem., 62, 394 (1958)

[11] Doyle CD, J. Appl. Polym. Sci., 15, 285 (1961)

[12] Zsako J, J. Phys. Chem., 72(7), 2406 (1968)

[13] Ozawa T, Bull. Chem. Soc. Jpn., 38, 1881 (1965)

[14] Ge Q, Kang S, Thermochim. Acta, 116, 71 (1987)

[15] Kim EH, Park JJ, Park JH, Chang IS, Choi CS, Kim SD, J. Nucl. Mater., 209, 294 (1994)

[16] Halldahl L, Toft Sorensen O, Proc. 6th Int. Conf. on Thermal Analysis, Bayrath, Germany, 499 (1980)

[17] Notz, Mendel, J. Inorg. Nucl. Chem., 14, 55 (1960)

[18] DeMarco, Mendel, J. Phys. Chem., 64, 132 (1960)

[19] Sheila A, Trans. Faraday Soc., 57, 1400 (1961)

[20] Dell, Wheeler, Trans. Faraday Soc., 58, 485 (1962)

[21] Le Page, France, J. Inorg. Nucl. Chem., 36, 87 (1974)

[22] Tompkims FC, "Treatise on Solid State Chemistry," ed. N.B. Hannay, Plenum Press, New York, 4 (1983)