What is the purpose of a paste backfill system in an open-pit mine?

The purpose of a paste backfill system in an open-pit mine is to improve slope stability, reduce the risk of subsidence, and provide a means of disposing of tailings or waste rock within the mined-out areas of the pit. Paste backfill is a mixture of finely ground tailings or waste rock, cement, and water that is pumped into the open pit to fill voids and create a stable backfill mass. Unlike conventional tailings disposal methods, which often involve storing tailings in surface impoundments, paste backfill allows for the tailing....