Solidification Characteristics of Limestone Calcined Coal Gangue Cement for Nickel-contaminated Soil

With the increase of carbon emissions,the use of sustainable and effective low-carbon and low-cost cementitious materials has attracted extensive attention in the stabilization/solidification of contaminated soil. In this study,unconfined compressive strength,toxicity characteristic leaching procedure,X-ray diffraction,scanning electron microscopy and other tests were carried out to determine the solidification characteristics of a new type of coal gangue cement calcined with low carbon and low cost limestone for heavy metal nickel contaminated soil. The results show that the strength increases with the curing age and decreases with the increase of nickel ion concentration. The leaching concentration of nickel ion decreases with the increase of curing age and increases with the increase of nickel ion concentration. The higher pH value（alkaline environment）is beneficial to promote the solidification efficiency of cement to heavy metal contaminated soil;X-ray diffraction and scanning electron microscopy show th