Study of the activated stripping tailings from limestone mines as the supplementary cementitious material

In view of the unused overburden and interlayer in limestone mining, it is proposed that the stripping tailings should be calcined and activated as supplementary cementitious materials.Combined with mechanical properties, basic properties (fluidity, water consumption for standard consistency, setting time and stability), synchronous thermal analysis and X-ray diffraction (XRD) tests, the results show that the stripping tailings of limestone mines are soft, and their chemical composition and mineral composition are close to those of silica-alumina clay minerals.During the calcination process, carbonate decomposition and mineral dehydration activation are found in the stripping tailings, which is certain pozzolanic activity.The highest activity of the stripping tailings is obtained at 800℃, with an activity index of 73% for 28 days.The cement-based materials are characterized by mercury injection (MIP).It is found that the porosity of the cement-based materials activated at 800℃, is smaller and the whole density is more compact, thus showing a higher macro-strength, which provided a new idea for the utilization of tailings.