在不同温度下对高pH和低pH的白丰富水泥进行固定
Raju Sharma1, Kunal Krishna Das1, Salman Siddique2
1Division of Architecture and Urban Design, Urban Science Institute, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon 22012, Republic of Korea.
Journal of hazardous materials
|March 16, 2024
概括
富含贝莱特的水泥 (BRC) 有效地固定,而较低的pH值提高了的流动性. 由于扩散减少,高pH的BRC在放射性废物处理方面表现出卓越的性能.
科学领域:
- 材料科学 材料科学 材料科学
- 地质化学 地质化学
- 环境科学 环境科学
背景情况:
- 放射性废物仓库需要稳定的材料来长期封存.
- 低pH水泥,特别是富含贝莱特的水泥 (BRC),正在研究其二氧化碳捕获和降低pH的能力.
- 了解在不同条件下BRC中的 (Cs) 固定是核废物管理的关键.
研究的目的:
- 为了评估pH值和温度对贝莱特丰富的水泥中的固定的影响.
- 为了确定BRC的物理化学特性和的移动性之间的关系.
- 评估BRC在核废物储存应用中的可行性.
主要方法:
- 高pH (空气固化) 和低pH (碳化) BRC样品的生产.
- 在25°C和45°C下进行90天的漏试验.
- 分析物理化学和形态特性,包括Si/Ca比率,矿物相和孔隙结构.
- 热力学建模用于预测相位稳定性.
主要成果:
- 在BRC pH和调动之间观察到一个反向相关性.
- 与低pH BRC (2.64E-07 cm2/s) 相比,高pH BRC对的有效扩散系数 (4.05E-09 cm2/s) 显著较低.
- 低pH BRC显示凝,石沉和孔隙连接性增加的Si/Ca比率下降,而高pH BRC在C-S-H凝和氧化物阶段的Si/Ca比率更高.
结论:
- 在BRC中的固定性强烈依赖于pH值,更高的pH值有利于更好的固定性.
- 在低pH下观察到的BRC微观结构和矿物学变化会对含量产生负面影响.
- BRC 证明了核废物储存的潜力,特别是在保持高pH值的条件下.
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