Abstract: Graphite tailing is a solid waste generated from the graphite mineral processing industry. It has been accumulated over one hundred million tons due to its difficult utilization technology, with a utilization rate of less than 20%, inducing significant environmental challenges. In this work, graphite tailings were employed as the primary raw material to prepare artificial aggregates via alkali-activated technology. The effects of forming process parameters, raw material composition, and curing conditions on the particle size distribution, water absorption, bulk density, particle shape coefficient, and cylinder strength of the artificial aggregates were systematically investigated. Furthermore, the phase composition and pore structure of the aggregates were characterized using X-ray diffraction (XRD) and mercury intrusion porosimetry (MIP). Experimental results demonstrated that the optimal pelletizing conditions involved a disc pelletizer with a tilt angle of 50°, rotation speed of 40 r/min, and pelletizing time of 40 minutes. The optimized conditions are 50% graphite tailings content, 3% alkali activator dosage (calculated as Na2O equivalent), and steam curing at 60 ℃ for 7 days. In this case, the prepared artificial aggregates achieve a peak cylinder strength of 21.6 MPa and a significantly reduced 1-hour water absorption of 2.3%. Increasing the proportion of graphite tailings leads to higher porosity and coarser pore structure, while an increase in the activator dosage first decreases and then increases the porosity. Most of pores in all the prepared artificial aggregate matrixes have diameters below 20 nm. The findings establish an innovative methodology for advancing the resource utilization of graphite tailings.
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2026, Vol. 40 
