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金属矿山 ›› 2020, Vol. 50 ›› Issue (05): 144-150.

• 协同开采 • 上一篇    下一篇

膏体—地聚物协同效应的铀尾矿井下充填处置体系构建

王富林,袁正平,陈国梁,杨仕教   

  1. 1. 南华大学资源环境与安全工程学院,湖南 衡阳 421001;2. 河南省矿产资源绿色高效开采与综合利用重点实验室,河南 焦作 454000
  • 出版日期:2020-05-15 发布日期:2020-06-12
  • 基金资助:
    国家自然科学基金青年科学基金项目(编号:51904154),国家安监总局安全生产重大事故防治关键技术科技项目(编号:hunan-0008-2016AQ),河南省矿产资源绿色高效开采与综合利用重点实验室开 放基金项目(编号:S201611)。

Construction of Uranium Tailings Underground Filling Disposal System with Synergistic Effectof Paste and Geopolymer

Wang Fulin,Yuan Zhengping,Chen Guoliang,Yang Shijiao   

  1. 1. School of Resource Environment and Safety Engineering, University of South China, Hengyang 421001,China;2. Henan Key Laboratory for Green and Efficient Mining & Comprehensive Utilization of Mineral Resources, Jiaozuo 454000,China
  • Online:2020-05-15 Published:2020-06-12

摘要: 铀尾矿井下充填处置是铀矿“协同开采”理念的重要技术支撑,但铀尾矿复杂的物理化学性质影响了胶结充填体的固结固化特性,进而制约了铀尾矿骨料胶结充填技术的应用。基于膏体和地聚物特性的协 同效应,针对铀尾矿地表堆置和常规井下充填处置存在的问题,提出了基于地聚物分割包裹—膏体稳固协同固化的铀尾矿井下充填设想。铀尾矿井下胶结充填体的技术指标包括机械强度、化学稳定、抗浸出性、氡析 出率和增容特性,物料组成包括铀尾矿骨料、地聚物基材、矿黏合剂、外加剂、功能矿物和水等,制备与充填过程的关键工艺为铀尾矿颗粒级配重构、充填材料多元复配以及充填质量的原位监测与动态调整技术。以 某铀尾矿库尾砂、复配冶炼矿渣等材料为研究对象进行了验证试验,当水固比为0.25、灰砂比为1:4时,充填体试件在(20±1)℃、湿度≥95%条件下养护28 d后,试件的最大单轴抗压强度为17.65 MPa,表明基于地 聚物的铀尾矿膏体充填体制备具备可行性。该充填体系的构建对于促进膏体充填技术在低或极低放射性固体废弃物处置领域的应用具有一定的意义。

关键词: 膏体充填, 地聚物, 铀尾矿, 协同效应, 井下充填

Abstract: The disposal of uranium tailings underground filling is an important technical support of the uranium "synergetic mining" concept. However, the complex physical and chemical properties of the uranium tailings affect the consolidation and solidification of the cemented backfill, and further restrict the application of the cemented backfill technology of the uranium tailings aggregate. Based on the synergistic effect of characteristics of paste and geopolymer, aiming at problems existing in the surface stacking of uranium tailings and the conventional underground filling disposal, a scientific idea of underground filling based on the fragmentation and wrapping of geopolymer and the stable and cooperative solidification of paste is put forward. The technical indexes of the cemented uranium tailings backfill include mechanical strength, chemical stability, leaching resistance, radon exhalation rate and compatibilization characteristics. The materials composition includes uranium tailings aggregate, geopolymer cementitious material, mineral binder, admixture and water, etc.. The key technologies in the preparation and filling process are particle grading reconstruction of uranium tailings, multiple compounding of filling materials, in-situ monitoring and dynamic adjustment of filling quality. Taking tailings of a uranium tailings pond and compound smelting slag as the study objects, the verification test was carried out. When the backfill with water-solid ratio of 0.25 and cement-sand ratio of 1:4 was cured at (20±1) ℃ and humidity ≥ 95% for 28 days, the maximum uniaxial compressive strength of the specimen was 17.65 MPa, which indicated that the preparation of uranium tailings paste filling system based on geopolymer is feasible. The construction of this system is of certain significance to promote the application of paste filling technology in the field of low or very low level solid waste disposal.

Key words: Paste filling, Geopolymer, Uranium tailings, Synergetic effect, Underground filling