This study investigates the hydration mechanism, phase assemblage, and strength characteristics of blended Portland limestone cement containing 15% Phosphate Beneficiation Tailing (PBT) and 15% limestone (LS). Hydration kinetics was studied using isothermal calorimetry, and X-ray diffraction revealed the phase evolution and structural transition occurring during hydration reaction. Furthermore, 7- and 28-day compressive strengths were used to assess strength development in the PBT-based Portland limestone cement (PBTPLC) and comparisons were made bench-marked with strength evolution in control Ordinary Portland cement and in Portland limestone cement. Results show that the hydration reaction of PBTPLC was delayed but also enhanced due to the presence of phosphorus and due to filler effect of PBT, respectively. The compressive strength of PBTPLC mortar specimens was comparable with that of PLC mortar specimens and satisfied codal minimum strength criteria for blended cement. Results of this study offer experimental support for utilization of PBT in production of Portland limestone cement, leading to conservation of scarce cement-grade limestone, lowering carbon emission and energy consumption in cement production, and promote effective waste management in the phosphate mining industry.