硅酸钠改性磷石膏道路稳定材料性能及固化机理

硅酸盐通报 ›› 2024, Vol. 43 ›› Issue (12): 4471-4479.

硅酸钠改性磷石膏道路稳定材料性能及固化机理

黄绪泉^1,2,3,4, 蔡家伟^1,2,3, 赵小蓉^1,2,3, 薛菲^1,2,3, 王豪杰^1,2,3, 王俊^1,2,3, 王明^1,2,3

1.三峡库区生态环境教育部工程研究中心(三峡大学), 宜昌 443002;
2.三峡大学水利与环境学院, 宜昌 443002;
3.固体废物处置与资源化利用宜昌市重点实验室(三峡大学), 宜昌 443002;
4.湖北省磷石膏资源化综合利用企校联合创新中心, 宜昌 443002

收稿日期:2024-05-13 修订日期:2024-07-19 出版日期:2024-12-15 发布日期:2024-12-19
通信作者: 赵小蓉,博士,副教授。E-mail:rongrong315@ ctgu.edu.cn
作者简介:黄绪泉(1975—),男,博士,副教授。主要从事固体废物处置与资源化的研究。E-mail:hxq@ctgu.edu.cn
基金资助:
三峡库区生态环境教育部工程研究中心开放基金(KF2022-11,KF2023-07);宜昌市自然科学研究项目(A23-2-020)

Performance and Curing Mechanism of Sodium Silicate Modified Phosphogypsum Road Stabilizing Material

HUANG Xuquan^1,2,3,4, CAI Jiawei^1,2,3, ZHAO Xiaorong^1,2,3, XUE Fei^1,2,3, WANG Haojie^1,2,3, WANG Jun^1,2,3, WANG Ming^1,2,3

1. Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region, Ministry of Education (China Three Gorges University), Yichang 443002, China;
2. College of Hydraulic & Environmental Engineering, China Three Gorges University, Yichang 443002, China;
3. Yichang Key Laboratory of Solid Waste Disposal and Resource Utilization (China Three Gorges University), Yichang 443002, China;
4. Hubei Province Enterprise-College Cooperation Innovation Center for Comprehensive Utilization of Phosphogypsum, Yichang 443002, China

Received:2024-05-13 Revised:2024-07-19 Published:2024-12-15 Online:2024-12-19

摘要/Abstract

摘要： 以磷石膏资源化利用为目的,探索了硅灰和水泥固化高浓度原状磷石膏制备道路稳定材料的最优配比设计,并以此为基础研究了硅酸钠增强道路稳定材料的性能,分析了固化机理。结果表明,当水泥、硅灰、消石灰的质量比为5 ∶3 ∶2,并加入1.5%(质量分数)的硅酸钠时,磷石膏道路稳定材料的力学性能和耐水性能显著提高,28 d无侧限抗压强度可达9.77 MPa,软化系数可达0.81,水稳系数可达1.0,同时浸出液中氟离子和可溶磷浓度满足《污水综合排放标准》(GB 8978—1996)一级限值。微观测试表明,水化反应产生的大量水化硅酸钙凝胶可将二水硫酸钙包裹,同时硅灰和硫酸钠的填充作用使整体结构更加密实,形成性能良好的磷石膏道路稳定材料。

关键词: 磷石膏, 硅酸钠, 混料设计, 无侧限抗压强度, 水稳系数, 软化系数, 浸出毒性

Abstract: With the purpose of resource utilization of phosphogypsum, this paper explored the optimal ratio design of silica fume and cement curing high-concentration original phosphogypsum to prepare road stabilizing materials, on this basis studied the performance of sodium silicate enhanced road stabilizing materials, and analysed the curing mechanism. The results show that when the mass ratio of cement, silica fume and slaked lime is 5 ∶3 ∶2, and 1.5% (mass fraction) of sodium silicate is added, the mechanical properties and water resistance of phosphogypsum road stabilizing materials are significantly improved, and the unconfined compressive strength of 28 d reaches 9.77 MPa, the softening coefficient reaches 0.81, and the water stability coefficient reaches 1.0. At the same time, the concentration of fluorine ions and soluble phosphorus in the leaching solution meets the first-level limit of the "Comprehensive sewage discharge standard" (GB 8978—1996). Microscopic tests show that a large amount of hydrated calcium silicate gel produced by the hydration reaction could wrap calcium sulfate dihydrate. At the same time, the filling effect of silica fume and sodium sulfate makes the overall structure more dense, forming a phosphogypsum road stabilizing material with good performance.

Key words: phosphogypsum, sodium silicate, mix design, unconfined compressive strength, water stability coefficient, softening coefficient, leaching toxicity

中图分类号:

TU526

黄绪泉, 蔡家伟, 赵小蓉, 薛菲, 王豪杰, 王俊, 王明. 硅酸钠改性磷石膏道路稳定材料性能及固化机理[J]. 硅酸盐通报, 2024, 43(12): 4471-4479.

HUANG Xuquan, CAI Jiawei, ZHAO Xiaorong, XUE Fei, WANG Haojie, WANG Jun, WANG Ming. Performance and Curing Mechanism of Sodium Silicate Modified Phosphogypsum Road Stabilizing Material[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2024, 43(12): 4471-4479.

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