2006-02-08_REVISION - M1983141 - Laserfiche WebLink

Home Browse Search

The general layout of a scope for resuming mining is shown in Figure 4. The cycle of drilling, blasting, mucking, pulling floor, raising chutes and manways, blasting and levelling waste and laying Boor is repeated on successive lifts until the next level is reached. Additional service raises are driven as the slope advances. Temporary pillars are left where a bad hangingwall requires support. In some places where the vein is over 2 ft. wide, sufficient waste fill cannot be obtained from slashing the foot- Mining Methods --- ~-~._ %~-~ ~ i ~~ i ~.~ iii" ;t ~~ •~' ~i r~~ :'°'~ ~ _ '.i.8' .i I ~.~ i /; ar s.r fiyuro 4. Sacliaa aAeriap ~/ Asap. lar nwawiq n'rp. gall without making the slope excessively wide. In such cases, additional waste, usually from develop- ment on other levels is dumped into the scope through the service raises. Sculls are placed where the ground needs additional support. particularly in the first two lifts above the drift back timber. All slope operations are on an incentive bonus system. Breaking and mucking is paid for by the square foot of vertical area extracted and chute and manway raising by the lift, floor laying by the square foot, chute pulling and tramming by the tan. Typical costs and consumption o[ major supplies and materials are shown in the accompany- ing table. Advantages of the method ate: The ore is extracted separately thus reducing dilution and maintaining a high grade. Scope openings are kept to an optimum working width. Fill is placed immediately after the extraction of orc thus minimizing the sloughing of walls. The fill is ordinarily obtained directly from the footwall and usually no additional fill from outside has to be transported into the slope. \o ore is tied up as in shrinkage scopes. 103 fipuro 3. Vtar A,rp. .4.:y lrsa~..I I~gaer>r vAer.: e«!<- •~