The mechanisms and drivers of lithification in slag-dominated artificial ground
The mechanisms and drivers of lithification in slag-dominated artificial ground
复制标题
矿渣为主的人工地基的石化机制和驱动因素
DOI：
10.1002/dep2.230
复制
发表时间：
2023
期刊：
影响因子：
--
通讯作者：
MacDonald J
中科院分区：
文献类型：
--
作者：
MacDonald J
松散的人工地基是地球表面不断增加的特征，但它带来了各种挑战，如污染物释放和地面不稳定性。岩化过程可能是改变人工地面特性和改善这些挑战的一个重要因素。在这项研究中，与前钢铁厂在苏格兰的炉渣的锂化存款进行了分析，以确定的机制和驱动力的锂化。扫描电子显微镜分析表明，钙浸出渣碎屑的边缘周围的化学不稳定的炉渣与水从附近的水体反应。炉渣中Ca（和OH−）的溶解导致与炉渣接触的水变得超碱性，促进了大气中CO2的吸收和羟基化（通过碳同位素分析进行指纹识别）。溶解的Ca和CO2反应导致方解石沉淀。扫描电子显微镜分析显示，方解石分布在矿渣碎屑之间，在碎屑周围形成边缘，并将碎屑粘合在一起形成固体岩石状物质。了解机制和驱动器的人工地面的石化将是重要的，因为它的广泛性，特别是在城市地区的人工地面是大多数发展的基板。
Unconsolidated artificial ground is an ever‐increasing feature on the Earth's surface but it poses various challenges such as pollutant release and ground instability. The process of lithification could be an important factor in changing the properties of artificial ground and ameliorating these challenges. In this study, a lithified deposit of a furnace slag associated with a former iron and steel works in Scotland was analysed to determine the mechanisms and drivers of lithification. Scanning electron microscope analysis showed that Ca leached from around the edges of clasts of slag through reaction of the chemically unstable slag with water from an adjacent water body. Dissolution of Ca (and OH−) from the slag caused the water in contact with the slag to become hyperalkaline, facilitating ingassing and hydroxylation of CO2from the atmosphere (fingerprinted through carbon isotope analysis). Reaction of the dissolved Ca and CO2led to precipitation of calcite. Scanning electron microscope analysis showed the calcite is distributed between slag clasts, forming rims around clasts and cementing clasts together into a solid rock‐like mass. Understanding the mechanisms and drivers of lithification in artificial ground will be important, given its widespread nature particularly in urban areas where artificial ground is the substrate of most development.