Investigation of muck drawing in blocks with trapezoid sills

The article is aimed at determining regularities of muck
drawing in blocks and developing the technology of enhancing of muck
ore parameters through shaping a trapezoid block sill. To confirm the
suggested assumptions, study regularities of forming and determine
contours of crests after full muck drawing from the second stage blocks,
laboratory experiments have been conducted on drawing muck ore on the
boundary with solidifying backfill massif of I stage stopes. For the first
time there have been determined numerical dependencies of ore losses in
crests on the contact with the solidifying backfill massif of the I stage
stopes after ore drawing from the II stage blocks on the dead stope height
and dips of side surfaces of trapezoid basis of sill pillars when forming the
trapezoid sill with inclined side surfaces of the lower part of the I stage
stopes. There are developed methods of calculating ore losses in crests on
the contact with the solidifying backfill massif of I stage stopes after muck
drawing from the II stage blocks. There are proposed methods of
determining optimal parameters of mining ore deposits considering
minimization of re losses in crests and increase of muck extraction from II
stage blocks.