Mine Planning and Mine Design

Mine Planning
Under Ground Mining Methods Khetri. Stopping Methods practiced in Indian Metal Mining

From Mines Plan and section, Khetri and Malanjkhand

Sub level Mining Methods Mine Planning by N G Nair Manager (Mines) Malanjkhand Copper Project. I worked at Khetri Copper complex, Hindustan Zinc Limited, Bharat Gold Mines Limited. 

From Mines Plan and section, Khetri and Malanjkhand

SUB LEVEL STOPING

Some autorites (eg. Higham) condiser it to be a variation of overhand stoping adapted to massive and wide ore deposits. However, the drill holes used in the stopes may be downwarde or in a ring or fan pattern and the stoping method is better treated as a seprate variety of open stping.

The method involves the driving of subleves within the orebody to vertically divide a block to be stoped. Miners working within the sublevel opening drill a pattern of holes, long holes of re. Ore is produced b drilling and blasting longholes which may range n diameter from 50-200 mm  with length up to 90 m. The ore falls into he large open stope created by previous blasts. For deposits of thickness less than 20m, sub-level for deposits width greater than 20m, the sub-level for deposits of width greater than 20m, the stopes may be formed in transverse direction. Ie. From handwall to footwall (transverse stopes). The method requires considerable preparatory work prior to stoping.

Vertical pillars are left between stopes on the same level. These are called rib pillars. Horizntal pillars are left to support the main haulage levels. The horizontal pillar for support of the upper level is called crown pillar; the one support of the lower level is called the sill pillar.