Study on the setting time and real-stope continuous filling strategy for metal mine backfill via a self-made simple iron cylinder

The interval time between successive filling processes in a stope is a critical parameter for metal mines. It is imperative to accurately determine this interval time. The relationship curves between curing time and heavy hammer settlement height under various types of cementing materials and slurry concentration conditions were obtained through the self-developed heavy hammer experiment. The mathematical model for the relationship between curing time and heavy hammer settlement height was fitted and regressed, with further analysis of the impact of slurry concentration and cementing material type on initial setting time. The results demonstrate an exponential relationship between curing time and heavy hammer settlement height, wherein the heavy hammer settlement height gradually decreases with increasing curing time. The initial setting time is significantly influenced by both the concentration of slurry and the type of cementing materials. Generally, with the same cementing material conditions, higher backfill concentrations result in shorter initial setting times. When the slurry concentration is 68 %, the initial setting time of A-type cementing materials occurs approximately 36.8 % earlier compared to that of C-type cementing materials, highlighting the crucial significance of selecting appropriate cementing materials for mine filling. The implementation of a consecutive filling strategy based on heavy hammer experimentation holds significant implications for enhancing the efficiency of mine filling, as exemplified by an iron mine in China.