Abstract: Advancements in exploration theory and equipment have significantly enhanced mine reserve expansion. However, adapting new resources in the deep periphery of mines to existing production systems requires reassessment, especially as sustainable stoping-and-filling operations face challenges from varying filling gradients and existing slurry transport parameters that no longer meet practical demands.To address these challenges, laboratory tests are conducted on the particle size distribution and slurry flow performance of backfill materials at the mine. Results identify an optimal slurry concentration range of 70%–72% by mass. Theoretical calculations assess the compatibility of current backfill system design with the filling gradients, establishing that a 70% slurry concentration supports a maximum self-flow filling gradient of 9.31, while 72% supports 5.56. To validate these findings, simulation models I (gradient 5), II (gradient 7), and III (gradient 9) demonstrate agreement with theoretical expectations. The results confirm that a 72% slurry concentration is suitable for self-flow backfill in older mine zones with filling gradients of 2.3–4.9, while reducing concentration to 70% enables self-flow in high-gradient (7.2–8.7) goafs in newly developed zones.For optimal technical and economic performance, we propose two strategies: (1) implementing additional pumps to transport 72% slurry under pressure, and (2) utilizing 70% slurry for gravity flow. A comparative analysis shows that the second strategy, which avoids technological modifications, offers a more reliable process and reduces operational costs by RMB2,334,500 compared to the first strategy. Therefore, the second strategy is the preferred option.