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    吴军, 张金生, 谈云志, 张晟, 李文琦, 明华军, 王冲. 磷石膏-矿渣-石灰固化底泥力学性能及微观机理[J]. 应用基础与工程科学学报, 2024, 32(5): 1360-1373. DOI: 10.16058/j.issn.1005-0930.2024.05.012
    引用本文: 吴军, 张金生, 谈云志, 张晟, 李文琦, 明华军, 王冲. 磷石膏-矿渣-石灰固化底泥力学性能及微观机理[J]. 应用基础与工程科学学报, 2024, 32(5): 1360-1373. DOI: 10.16058/j.issn.1005-0930.2024.05.012
    WU Jun, ZHANG Jinsheng, TAN Yunzhi, ZHANG Sheng, LI Wenqi, MING Huajun, WANG Chong. Mechanical Properties and Microscopic Mechanism of Phosphogypsum-Slag-Lime Solidified Sediment[J]. Journal of Basic Science and Engineering, 2024, 32(5): 1360-1373. DOI: 10.16058/j.issn.1005-0930.2024.05.012
    Citation: WU Jun, ZHANG Jinsheng, TAN Yunzhi, ZHANG Sheng, LI Wenqi, MING Huajun, WANG Chong. Mechanical Properties and Microscopic Mechanism of Phosphogypsum-Slag-Lime Solidified Sediment[J]. Journal of Basic Science and Engineering, 2024, 32(5): 1360-1373. DOI: 10.16058/j.issn.1005-0930.2024.05.012

    磷石膏-矿渣-石灰固化底泥力学性能及微观机理

    Mechanical Properties and Microscopic Mechanism of Phosphogypsum-Slag-Lime Solidified Sediment

    • 摘要: 采用石灰作为碱性激发剂激发工业废渣(磷石膏和矿渣)的活性用于固化河湖底泥,可减少能源消耗和环境污染,形成“以废治废”的绿色发展模式.基于此提出了以磷石膏-矿渣-石灰三元固化剂(PSCA)对河湖底泥进行固化的方法.首先,采用无侧限抗压强度试验研究了不同掺量PSCA和养护龄期对固化底泥力学性能的影响;然后,借助扫描电镜、X射线衍射和压汞试验从水化产物和孔隙结构角度揭示了其固化机理.试验结果表明:PSCA固化底泥早期强度较低,但后期强度增长较快,28d强度可达到1.53MPa,高于同掺量普通硅酸盐水泥固化底泥的强度.微观结果表明PSCA固化底泥中含有大量的絮状C-S-H产物和针棒状钙矾石晶体,前者主要贡献胶凝强度,而后者主要贡献密实强度.经济和环境分析表明PSCA单位强度成本(28d龄期)和碳排放量分别为水泥的59.1%和14倍,具有良好的经济和环境效益.该研究成果可为底泥提供一种可持续固化材料和技术,对我国底泥和固废的安全处理和资源化利用具有重要的科学意义和实用价值.

       

      Abstract: The utilization of using lime as an alkaline activator to improve the activity of industrial byproducts (i.e.,phosphogypsum and slag) is an approach to solidify river and lake sediments,which can reduce energy consumption and environmental pollution and form a green development model of “treating waste with waste”.The study proposes a method of solidifying river and lake sediment using phosphogypsum-slag-lime ternary stabilizer (PSCA).Firstly,the unconfined compressive strength (UCS) test was used to study the effects of PSCA dosages and curing periods on the mechanical properties of solidified sediment.Then,scanning electron microscopy (SEM),X-ray diffraction (XRD),and mercury intrusion porosimetry (MIP) tests were used to reveal the microscopic mechanism of hydration products and pore structure.The results indicate that the strength of PSCA solidified sediment is low in the early curing stage,but the strength increases rapidly in the later stage,and the strength can reach 1.53MPa in 28 days,which is higher than those solidified by ordinary Portland cement with the same dosage.Microscopic results show that the PSCA solidified sediment contains a large amount of flocculent C-S-H products and needle-shaped ettringite crystals.The former mainly contributes to the bonding strength,while the latter mainly contributes to the filling strength.Economic and environmental analysis shows that the unit strength cost (28 days) and carbon emissions of PSCA are 59.1% and 14 times that of traditional ordinary Portland cement,respectively,exhibiting good economic and environmental benefits.Overall,this research results can provide a sustainable solidification material and technology for sediment,which has important scientific significance and practical value for the safe treatment and resource utilization of sediment and solid waste in China.

       

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