Dissolution Characteristics of Lead Sulfate in Borosilicate Glass Melt

Abstract

Abstract: During vitrification of high-level liquid waste with high content of sulfur and sodium, Na₂SO₄ is very easy to decompose and separate from the glass melts. In this paper, it was proposed that Na₂SO₄ in the high-level liquid waste was converted into PbSO₄ by addition a proper amount of Pb(NO₃)₂ solution, and then the borosilicate glass solidified body was prepared by melting method. The dissolution characteristics of PbSO₄ in glass melt was observed in situ for the first time by high temperature confocal scanning laser microscope, which has been widely used in steel materials. The thermal stability of PbSO₄ mixed with borosilicate glass at different temperatures (800 ℃ to 1 150 ℃) and the sulfur content in glass were investigated. The results show that borosilicate glass samples with 6% (mass fraction) SO₃ introduced in the form of PbSO₄ are homogeneous glass-ceramics at both 800 ℃ and 900 ℃. The glass-ceramics mainly possess SiO₂ phase along with a small amount of BaSO₄ and PbSO₄ phases at 800 ℃. The content of SiO₂ crystal decreases while the BaSO₄ crystal content increases, and PbSO₄ phase disappears and CaMgSi₂O₆ phase appears at 900 ℃. A white separated phase begins to appear on the glass surface composed of PbO, BaSO₄ and LiNaSO₄ crystals at 1 000 ℃. In addition, the round shape PbO crystals grow gradually and BaSO₄ crystals change from block to strip shape with the temperature increasing from 1 000 ℃ to 1 100 ℃. The sulfur content in the glass remains unchanged at 800 ℃ to 1 000 ℃, and decreases obviously with further increasing the temperature.

Key words: high-level liquid waste, borosilicate glass, lead sulfate, dissolution, solidification, high temperature confocal scanning laster microscopy

CLC Number:

TQ171

YAO Ying, ZHANG Zhuangsen, WANG Bin, LIAN Qihui, LI Huidong, WU Lang. Dissolution Characteristics of Lead Sulfate in Borosilicate Glass Melt[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2022, 41(3): 1044-1052.

References

[1] 王建晨,陈靖.我国高放废液中铯分离研究进展[J].核化学与放射化学,2019,41(1):27-39.
WANG J C, CHEN J. Progress on partitioning of cesium from high level liquid waste in China[J]. Journal of Nuclear and Radiochemistry, 2019, 41(1): 27-39 (in Chinese).
[2] 李玉松,张生栋,鲜亮,等.CIAE高放废液固化技术研发进展[J].原子能科学技术,2020,54(s1):126-136.
LI Y S, ZHANG S D, XIAN L, et al. Progress in research and development of vitrification technology for high-level radioactive liquid waste at CIAE[J]. Atomic Energy Science and Technology, 2020, 54(s1): 126-136 (in Chinese).
[3] 罗上庚.玻璃固化国际现状及发展前景[J].硅酸盐通报,2003,22(1):42-48.
LUO S G. Status and prospect of vitrification technology[J]. Bulletin of the Chinese Ceramic Society, 2003, 22(1): 42-48 (in Chinese).
[4] YANIKOMER N, ASAL S, HACIYAKUPOGLU S, et al. New solidification materials in nuclear waste management[J]. International Journal of Engineering Technologies, 2016, 2(2): 76.
[5] 王孝强,庹先国,周慧,等.高硫高钠高放废液玻璃固化配方研究[J].核化学与放射化学,2013,35(3):180-192.
WANG X Q, TUO X G, ZHOU H, et al. Glass formulation development on high-sodium and high-sulfur bearing high level liquid waste for vitrification process[J]. Journal of Nuclear and Radiochemistry, 2013, 35(3): 180-192 (in Chinese).
[6] 刘丽君,郄东生,周慧,等.高硫高钠高放废液玻璃固化的配方验证[J].核化学与放射化学,2014,36(3):163-168.
LIU L J, QIE D S, ZHOU H, et al. Verification experiment research of glass formulation for high sodium and high sulfur bearing HLLW[J]. Journal of Nuclear and Radiochemistry, 2014, 36(3): 163-168 (in Chinese).
[7] REMIZOV M B, KOZLOV P V, VLASOVA N V, et al. Thermal and electrical conductivity of molten alumophosphate and borosilicate glass containing imitators of high-active wastes from SNF processing[J]. Glass Physics and Chemistry, 2018, 44(6): 557-563.
[8] 刘丽君,徐建华,姜耀中.玻璃固化过程中硫酸盐分相和分解行为研究[J].原子能科学技术,2015,49(9):1551-1556.
LIU L J, XU J H, JIANG Y Z. Study on sulfate phase segregation and decomposition in vitrification process[J]. Atomic Energy Science and Technology, 2015, 49(9): 1551-1556 (in Chinese).
[9] PLODINEC M J. Vitrification chemistry and nuclear waste[J]. Journal of Non-Crystalline Solids, 1986, 84(1/2/3): 206-214.
[10] 李秀英,肖卓豪,陶歆月,等.高水平放射性废物固化用磷酸盐玻璃的研究进展[J].材料导报,2021,35(5):5032-5039.
LI X Y, XIAO Z H, TAO X Y, et al. Research progress on the vitrification of high level radioactive wastes in phosphate glassy matrices[J]. Materials Reports, 2021, 35(5): 5032-5039 (in Chinese).
[11] JANTZEN C M, SMITH M E, PEELER D K. Dependency of sulfate solubility on melt composition and melt polymerization[M]. Environmental Issues and Waste Management Technologies in the Ceramic and Nuclear Industries X, 2004, 168: 141-152.
[12] BANERJEE S, TYAGI A. Functional materials: preparation, processing and applications[M]. Elsevier, 2011.
[13] JAHAGIRDAR P B, WATTAL P K. Vitrification of sulphate bearing high level wastes in borosilicate matrix[J]. Waste Management, 1998, 18(4): 265-273.
[14] WU L, XU L G, JIANG F, et al. Microstructure, sulfate retention, and aqueous stability of barite-borosilicate glass-ceramics[J]. Journal of Nuclear Materials, 2019, 516: 152-159.
[15] 江枫,吴浪,雷杰,等.硼硅酸盐玻璃成分对硫酸钡热稳定性的影响[J].玻璃,2020,47(2):9-16.
JIANG F, WU L, LEI J, et al. Effect of borosilicate glass composition on the thermal stability of Barium sulfate[J]. Glass, 2020, 47(2): 9-16 (in Chinese).
[16] 雷杰,吴浪,江枫,等.制备工艺对重晶石-硼硅酸盐玻璃陶瓷结构及性能的影响[J].硅酸盐通报,2020,39(4):1289-1295.
LEI J, WU L, JIANG F, et al. Effect of preparation process on structure and properties of barite-borosilicate glass-ceramics[J]. Bulletin of the Chinese Ceramic Society, 2020, 39(4): 1289-1295 (in Chinese).
[17] 王昌,王辉,张超,等.高温激光共聚焦显微镜在钢铁材料中研究进展[J].物理测试,2019,37(6):15-26.
WANG C, WANG H, ZHANG C, et al. A review on high temperature confocal scanning laser microscope applied in steel materials[J]. Physics Examination and Testing, 2019, 37(6): 15-26 (in Chinese).
[18] 王孝强.高硫高钠高放废液的玻璃固化配方研究[D].成都:成都理工大学,2013.
WANG X Q. Studies of high-sufur, high-sodium, high radioactivity liquid waste vitrification formulation[D]. Chengdu: Chengdu University of Technology, 2013 (in Chinese).
[19] MANARA D, GRANDJEAN A, PINET O, et al. Sulfur behavior in silicate glasses and melts: implications for sulfate incorporation in nuclear waste glasses as a function of alkali cation and V₂O₅ content[J]. Journal of Non-Crystalline Solids, 2007, 353(1): 12-23.
[20] KAUSHIK C P, MISHRA R K, SENGUPTA P, et al. Barium borosilicate glass-a potential matrix for immobilization of sulfate bearing high-level radioactive liquid waste[J]. Journal of Nuclear Materials, 2006, 358(2/3): 129-138.
[21] TAN S H. The incorporation and solubility of sulphate, chloride and molybdate anions in borosilicate and aluminosilicate glasses[D]. Sheffield: The University of Sheffield, 2015.
[22] MISHRA R K, SUDARSAN K V, SENGUPTA P, et al. Role of sulfate in structural modifications of sodium barium borosilicate glasses developed for nuclear waste immobilization[J]. Journal of the American Ceramic Society, 2008, 91(12): 3903-3907.