Stoping

The specific method of stoping depends on a number of considerations, both technical and economical, based largely on the geology of the ore body being mined.

[3] It is common to dig shafts vertically downwards to reach the ore body and then drive horizontal levels through it.

When the ore body is more or less horizontal, various forms of room and pillar stoping, cut and fill,[4] or longwall mining can take place.

In steeply-dipping ore bodies, such as lodes of tin, the stopes become long narrow near-vertical spaces, which, if one reaches the surface is known as a gunnis or goffen.

The method requires that the hanging wall and often the footwall be of competent rock as the stulls provide the only artificial support.

Depending on rock conditions and other technical considerations, once the stope has reached its engineered height, it may be left open or backfilled for support.

A common historical method of hydraulic fill involved dumping waste rock into a completed stope, then slurrying in a mixture of mill sand and water.

[11] Long hole stoping is a highly selective and productive method of mining and can cater for varying ore thicknesses and dips (0 – 90 degree).

It differs from manual methods such as timbered and shrinkage as once the stope has begun blasting phase it cannot be accessed by personnel.

For this reason the blasted rock is designed to fall into a supported drawpoint or removed with remote control LHD (load, haul, dump machine).

Sketch painting of miners stoping at the Burra Burra Mine, Burra, Australia, 1847.
Stoping with an air drill in an American iron mine in the 20th century (museum exhibit)
A large stope converted into a chapel in a salt mine in Poland – now open to tourists
A large stope in the Treadwell gold mine, Alaska 1908; an example of shrinkage stoping