Stabilization/Solidification of Ladle Slag in Cement-stabilized Clay
Ladle furnace basic slag (ladle slag) is a by-product generated from the secondary steelmaking industry. The subsequent disposal of this slag in Singapore is problematic due to its quantity and impact on the environment. A possible solution is to incorporate the ladle slag with deep cement mixing for soft ground improvement. Hence, this study investigates the stabilization/solidification of the ladle slag in the cement-stabilized clay, focusing on the influence of ladle slag on mechanical properties of cement-stabilized soft clay and the leaching of heavy metals. A range of laboratory tests were conducted, including unconfined compressive strength (UCS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and leaching tests. The results showed the addition of ladle slag slightly reduced the UCS of cement-stabilized clays at 14 days, but did not affect or even slightly increased the UCS at and after 28 days if the ladle slag/cement ratio was within 0.15. The leaching of heavy metal elements all meet the requirement of the non-hazardous waste standard. This implies the potential incorporation of ladle slag into soft clay stabilization as a sustainable waste management strategy.
KeywordsLadle slag Soft clay stabilization Unconfined compressive strength Microstructure
The authors appreciate the support from Singapore MOE AcRF Tier 1 grant (RG184/17) and NTU URECA programme (CEE17065).
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