Abstract: The paper presents the backfilling technology of high density total tailings prepared by a new type vertical sand silo.Extremely fine total tailings are directly prepared into high density slurry by a special vertical sand silo using slurry making technology with rationally controlled pressure for assisting the tailing flow.Control Cement and other auxiliary materials are added into the tailings in the proportion as test specified, which are fully agitated and adjusted to the required density.High density total tailings thus prepared or cemented total tailings are transported to the deep underground mined-out area by gravity.The technology can effectively control the geopressure of the stoping area so as to realize a safe and efficient deep mining.It can be widely used in mining-backfilling mines, laying a foundation for non-waste mining and being of enormous significance to promoting and transforming the mining process of metal mines.

Key words: High density tailings, Total Tailings Backfill, Vertical , silo, Deep underground metal mine, Large scale