Research progress on mining with backfill technology of underground metalliferous mine

Mining with backfill has been used extensively in underground metal mines which is an important way to conduct green and low⁃carbon mining operations. Backfill technologies can achieve both the maximum recovery ratio of underground mineral resources and the environment⁃friendly disposal of mining wastes. This paper systemati⁃ cally reviewed the recent development of mining with backfill methods. The progress of new technology application were introduced from three aspects:High⁃efficiency and large⁃scale mining with backfill，continuous mining with back⁃ fill methods，and reduction of backfill costs in underground mining. Then the evolution and development of the min⁃ ing technologies with backfill used in metal mine were introduced. The application and development trends of the whole process of backfill technology covering the preparation and transportation of tailings slurry，barricades design and the drainage of backfill slurry in the stope were analyzed. The mechanism of heterogeneous characteristics and self⁃weight consolidation behavior of tailings backfill slurry were analyzed，and the comparisons between the tradition⁃ al methods used for strength requirement design of the backfill structure and the improved strength calculation⁃de⁃ sign methods for backfill in mine stopes were made. In addition，the in⁃situ monitoring methods of the backfill slurry to assess the field backfill quality were introduced. Based on the above research，it was obtained that the revolution of mining with backfill methods was the crucial path to achieve a high⁃efficiency，large⁃scale and low⁃cost under⁃ ground mining. The innovations on key points in the whole process of mine backfill were necessary measures for the stable preparation and utilization of high⁃quality underground backfill slurry. Most importantly，an in⁃depth study on the backfill mechanics of different mining methods was essential to ensure a safe，green，economical，and convenient application of mining with backfill. In the end，the research aspects and directions that should be focused on in the fu⁃ ture were clarified. It pointed out that accelerating the development of new technologies，new materials and new equip⁃ ment for green and low⁃carbon backfill was the driving force to promote the transformation and development of mine backfill operation.