辐射防护 ›› 2022, Vol. 42 ›› Issue (1): 11-17.

• 综述 • 上一篇    下一篇

花岗岩氡析出影响因素研究进展

龙淑琴, 谢焱石, 谭凯旋, 张明华, 单健, 王升   

  1. 南华大学资源环境与安全工程学院 稀有金属矿产开发与废物地质处置技术湖南省重点实验室,湖南 衡阳 421001
  • 收稿日期:2021-07-08 出版日期:2022-01-20 发布日期:2022-01-24
  • 通讯作者: 谢焱石。E-mail: xie_yanshi@qq.com
  • 作者简介:龙淑琴(1997—),女,2019年毕业于北部湾大学地理科学专业,现为南华大学地质资源与地质工程专业硕士研究生。E-mail:1373521381@qq.com
  • 基金资助:
    国家自然科学基金项目(U1703123);东华理工大学放射性地质与勘探技术国防重点学科实验室开放基金项目(RGET1602)。

Research progress on influencing factors of radon exhalation in granite

LONG Shuqin, XIE Yanshi, TAN Kaixuan, ZHANG Minghua, SHAN Jian, WANG Sheng   

  1. School of Resource Environment and Safety Engineering,University of South China Hunan Key Laboratory of Rare Metal Minerals Exploitation and Geological Disposal of Wastes,Hunan Hengyang 421001
  • Received:2021-07-08 Online:2022-01-20 Published:2022-01-24

摘要: 随着对氡气危害认识的加深,花岗岩作为生产、生活上接触较多的天然辐射来源,其氡析出特征对人居环境的辐射影响得到广泛关注。本文从岩石的原生特性和次生变化两方面对花岗岩的氡析出进行文献综述,发现花岗岩氡析出与岩石化学成分、矿物成分和成因类型等原生特性以及次生风化和蚀变导致的放射性核素分布、矿物颗粒大小以及岩石微裂隙等因素密切相关。研究表明,铀镭活度与花岗岩氡析出表现出线性相关,但受铀赋存矿物类型的影响,矿物成分的具体影响还需进一步研究,可能与其构造背景或者物质来源有关。岩石次生变化对花岗岩氡析出的影响主要表现为风化和蚀变使得放射性核素迁移到颗粒表面和岩石裂隙等有利于氡析出的位置,而颗粒变小比表面积增大以及岩石内表面积和孔隙率增加使得铀镭发生富集和逃逸,从而最终促进岩石氡的析出。岩石原生特性和次生变化对花岗岩的氡析出起着重要的影响作用,铀镭活度可以作为花岗岩氡析出率潜力的预测指标,而对于矿物成分和岩石的次生变化则是研究花岗岩氡析出的重要潜在因素。故此,未来需要系统研究并定量描述岩石化学、矿物成分和次生变化,并据此建立合理有效的岩石氡析出模型,帮助更全面地掌握岩石中氡析出规律,为地下工程及人居环境的氡防护提供理论依据。

关键词: 氡析出, 花岗岩, 岩石特性, 风化和蚀变作用

Abstract: With the deepening awareness of radon hazards, granite is a natural radiation source to which people are more often exposed in production and daily life. Granite's radon exhalation characteristics and its radiation impact on human settlements have been widely attention. In this paper, a literature review has been made for radon exhalation in granite from two aspects ofprimary properties and secondary changes of rocks. It is found that the radon exhalation of granite is relevant to the primary properties of rock chemical composition, rock mineral composition, and rock genetic type, as well as secondary factors caused by weathering and alteration such as the distribution of radionuclides, the size of mineral granules and rock micro-cracks. Researches show that there is a linear correlation between both uranium activity and radium activity and radon exhalation rate in granite, but this will be affected by the types of uranium-occurring minerals, the specific impact of mineral composition needs further study, which may be related to its structural background or material source. The effect of secondary changes on radon exhalation in granite is mainly manifested in weathering and alteration that cause radionuclides to migrate to the granule surface and rock fractures that are favorable for radon exhalation. Secondly, the granule size decreases and the specific surface area increases, and the internal surface area and pores of the rock also increase. These changes makes uranium and radium enrich and escape, which ultimately promotes the radon exhalation from the rock. Both the primary properties and secondary changes of rock play an important role in the radon exhalation in granite. Uranium and radium activity can be used as a predictor of the potential for radon exhalation rate in granite, while the mineral composition and the secondary changes of granite are important potential factors for the study of radon exhalation in granite. Therefore, it is necessary to systematically study and quantitatively describe chemical composition, mineral composition and these secondary changes, and establish a reasonable and effective rock radon exhalation model in the future, so as to more comprehensively grasp the rules of radon exhalation in the rocks, and provide a theoretical basis for radon exhalation in underground engineering and human settlements.

Key words: radon exhalation, granite, rock properties, weathering and alteration

中图分类号: 

  • P642