SUB LEVEL STOPING
Sublevel means a level intermediate between the two main adjacend levels driven during the development stage. It is confined to the block or ore and does not extend to the shaft.
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 stoping.
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
UNDERGROUND MINING METHODS AT KOLAR GOLD FIELDS, Bharat Gold Mines Limited KGF, School of Mines KGF, Rajasthan State Mineral Development Corporation, School of Mines KGF, Indian Copper Complex - Old History, Stoping methods - Indian Copper Complex, Mine Plan and Mine Design, Surpac Mining Software Training at Malanjkhand, Down the Hole Production Drilling Pattern ,KHETRI AND KOLIHAN MINES
Blast Hole Open Stopes Blasting to Improve Fragmentation in Mines ,Coal Mining Vs. Metalliferous Mining ,Development of an underground metal mine
Lead and Zinc Under Ground Mining Methods , Raising methods in metal Mines Typical Sub Level Stopes (54mm dia holes)
Mining Companies I've worked for, Hindustan Zinc Limited,; Hindustan Copper Limited; Bharat Gold Mines Limited; Rajsthan State Mineral Development Corporation; Rajasthan State Industrial & Mineral Development Corporation; Khetri Copper Complex; Malanjkhand Copper Project; Kolihan Copper Mines; Mahi Graphite Project Rajasthan; Rajasthan Felspar Project Dungarpur, Rajasthan