无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2025, Vol. 57 ›› Issue (5): 93-99.doi: 10.19964/j.issn.1006-4990.2024-0413

• 环境·健康·安全 • 上一篇    下一篇

磷石膏复合胶凝材料力学性能与微观特性研究

王丰1(), 宋宇1, 何兆益2, 夏羽花3(), 毕研立1, 冯浩1, 曹东伟4   

  1. 1.中冶建工集团有限公司,重庆 400037
    2.重庆交通大学交通运输学院,重庆 400074
    3.重庆交通大学土木工程学院,重庆 400074
    4.交通运输部公路科学研究院,北京 100088
  • 收稿日期:2024-07-19 出版日期:2025-05-10 发布日期:2024-08-12
  • 通讯作者: 夏羽花(2001— ),女,在读硕士研究生,主要研究方向为固废材料资源化利用;E-mail:2022467498@qq.com
  • 作者简介:王丰(1983— ),男,高级工程师,主要研究方向为道路与桥梁工程固体废物资源化利用;E-mail:156993217@qq.com
  • 基金资助:
    电解锰渣规模化综合利用技术研究项目(cstc2021 jscx-jbgsX0006)

Study on mechanical properties and microscopic characterization of phosphogypsum composite cementitious materials

WANG Feng1(), SONG Yu1, HE Zhaoyi2, XIA Yuhua3(), BI Yanli1, FENG Hao1, CAO Dongwei4   

  1. 1. MCC Construction Engineering Group Co. ,Ltd. ,Chongqing 400037,China
    2. School of Transportation,Chongqing Jiaotong University,Chongqing 400074,China
    3. School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China
    4. Highway Science Research Institute of the Ministry of Transport,Beijing 100088,China
  • Received:2024-07-19 Published:2025-05-10 Online:2024-08-12

摘要:

磷石膏堆存量巨大且含有大量硫酸盐、磷、氟、重金属等有害物质,若处置不当将会对环境造成严重危害。为解决此问题,利用磷石膏中含有CaSO4·2H2O的特点,采用矿渣、Ca(OH)2、Na2SO4等材料协同制备磷石膏复合胶凝材料,并系统研究其力学性能、水化机理、微观结构及浸出毒性特征。研究结果表明:磷石膏复合胶凝材料的抗压强度随Ca(OH)2掺量的增加呈先减后增趋势,随磷石膏掺量的增加则呈先增后减趋势,最优配合比确定为67%矿渣、30%磷石膏、3% Ca(OH)2及外掺3% Na2SO4,在此配合比下,材料3、7、28 d的抗压强度分别达到4.12、25.21、37.45 MPa;Ca(OH)2掺量的增加能够加速磷石膏分解释放SO42-与Ca2+,同时促进矿渣中硅氧四面体和铝氧四面体的分解,这些成分通过水化反应形成大量钙矾石和C-(A)-S-H凝胶,且相互交织构成致密的网络结构。在浸出毒性方面,磷石膏中F-、PO43-的质量浓度分别为148.23、298.24 mg/L,而制备的胶凝材料中F-、PO43-的质量浓度分别下降至2.34~4.32 mg/L和0.05~0.18 mg/L。此外,胶凝材料中的所有污染物指标均满足GB 8978—1996《污水综合排放标准》的要求。

关键词: 磷石膏, 胶凝材料, 力学性能, 水化机理, 浸出毒性

Abstract:

The large stockpiles of phosphogypsum,which contain a large amount of sulfate,phosphorus,fluorine,heavy metals and other harmful substances,pose environmental risks if improperly managed.To address this issue,the CaSO4·2H2O content in phosphogypsum was leveraged,combined with slag,Ca(OH)2,and Na2SO4,to prepare phosphogypsum composite cementitious materials. their mechanical properties,hydration mechanism,microstructure,and leaching toxicity were investigated.The results showed that the compressive strength of the phosphogypsum composite cementitious material was initially decreased then increased with the addition of Ca(OH)2 and initially increased then decreased with the addition of phosphogypsum.The optimal mix ratio was 67% slag,30% phosphogypsum,3% Ca(OH)2 and 3% Na2SO4,and the compressive strength of 3 d,7 d and 28 d could reach 4.12,25.21 and 37.45 MPa,respectively.Increasing the Ca(OH)2 content accelerated the decomposition of phosphogypsum into SO₄²⁻ and Ca²⁺,which in turn promoted the breakdown of silicon-oxygen and aluminum⁃oxygen tetrahedra in the slag.These components then hydrated to form large amounts of ettringite and C-(A)-S-H gel,which interweaved to form a dense network structure.The concentrations of F- and PO43- in phosphogypsum leachate were 148.23 and 298.24 mg/L,respectively,while in the cementitious material,they were decreased to 2.34~4.32 mg/L and 0.05~0.18 mg/L,respectively.Additionally,all pollutants in the cementitious material met the GB 8978—1996 Integrated Wastewater Discharge Standard.

Key words: phosphogypsum, cementitious materials, mechanical properties, hydration mechanism, leaching toxicity

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