The Totten Mine deposits consists of the actively mined Totten Main (215), and other mineralized zones including the 230, 260, 242, 235, 238, 238 West, Howland, and McIntyre zones.
Slot–slash and Mechanized cut-and-fill mining methods are employed for ore extraction. Most of the main ore body at the Totten Mine is mined using transverse primary–secondary stoping. Longitudinal stoping is used in narrow portions of orebodies and in stopes adjacent to trap dykes.
Mix of mill rock tailings and alluvial sands are used for backfilling.
Slot–Slash
Slot–slash mining is a bulk mining method that entails blasting vertical slices of ore to a free face, which initially will be a blasted inverse raise, or a bored raise. The amount of ore that can be blasted at any given time is limited to the existing void space and the available free face. Blastholes are loaded with staggered decks to break anywhere from 6 m to the entire length of the hole. The blocks are slashed out to the stope boundaries and up to a crown. The final crown is taken in one blast.
This method concentrates loading and blasting operations, and, once a slot has been established, stopes of 25,000–40,000 t of ore can be completely broken in 3–5 separate blasts, while smaller stopes can be blasted in one blast.
Blastholes are drilled using in-the-hole (ITH) drills. Prior to blasting, long blastholes are surveyed in order to determine their location and all holes ........