These projects will all have ore throughput rates of around 100,000 metric tons per day or greater and, to provide the support infrastructure and the footprint for such outputs, rapid mine development is critical to source ore from a first drawpoint
MacLean, a former Inco employee who worked in Sudbury, developed drawpoint
obstruction clearance machines for block caving rigs, including blockhole jumbos in the late 1970s.
* an offset herringbone drawpoint
layout to facilitate the use of electric loaders.
loading has been introduced to the mining areas of both shafts.
SOB's mixed VCR/SLC section operates two Elphinstone R1300 3.5 [m.sup.3] LHDs on drawpoint
loading and has a Sandvik Tamrock Toro 151D for development work, 10-15 m/d of development drive mucking.
In the 1980s, mines begin to experiment with LHDs controlled by teleremote systems, removing the operator from the mucking process at the drawpoint
. The technology matures to the point where one operator is controlling two or three LHDs from a central controls station on the surface.
"The hydraulic radius needed to initiate caving, fragmentation, drawpoint
spacing, secondary blasting and the possibility of seismicity are geotechnical concerns that are being addressed.
A steel plate fitting over this raise is placed on whichever level the backfill is required to block the raise and collect the fill by, effectively, forming a backfill drawpoint
. Toro 6.1 [m.sup.3] LHDs are used to load backfill from the raise directly into the stopes.
That the mine has only been able to achieve that proportion despite a long involvement with automation projects is a reflection on the complexity involved, with the LHDs being controlled during loading by the operator in the control room, then traveling autonomously to the dump and back to the next scheduled drawpoint
All that is required is that the machine be driven, either by an operator in the cab or teleremotely, along the route to the orepass and then back to the drawpoint
. This is sufficient for Infrafree to learn the route.
Develop "measurables," such as best cycle times, drawpoint
and haul road condition, payload accuracy, etc.
In the Esmeralda project, they will be used as boxhole-boring (up-hole) machines for drawpoint
slot hole drilling and shaft development.