Stoping Methods

The production centers of the mine are the stopes. It is in this area where the ore is first broken.

Selecting an appropriate mining method is the paramount consideration for the safety of the people that work in the mines. Even then, miners must be constantly alert and on their guard to make the place where they work as safe as they possibly can. A constant potential danger is the rocks which are loose. As soon as a miner enters a stope, the back is examined meticulously, and any material which is loose is brought down with a scaling bar.

A stope must also be designed so that miners can reach their working locations, remove the broken ore, and get supplies, tools, explosives and equipment in. It must also be ventilated continuously and properly so that the environment in which they are situated does not fill with machine exhausts and dust. Ventilation also helps to mantain the temperature of the air low enough for miners to work in very deep mines where the wall rocks can be very hot.

Stopes are started from the principal levels in a mine. The primary step of the operation is known as silling – cutting a drift across the bottom or top of the ore to be mined.

There are quite a few ways of removing ore from a stope. The sill can consist of a wooden structure placed in a section of a crosscut which has had a slice taken out of the back. This structure will include chutes for the removal of the broken ore from the stope to be developed on top of the crosscut. It will also include the startings of the manways which have to be mantained for access and for services like electricity, water and compressed air.

In other instances, a series of short box holes or raises are opened in the rock. They are dug out at short intervals along the drift, or in the footwall which is parallel to it.

Development work for some stoping methods calls for a very elaborate system of box holes. This is needed for the ore removal from scraper drifts, which in turn are fed from drawpoints which are underlying a stope that extends for quite a distance along the strike. Development work for a stope most of the time includes rib pillars (which are oriented at right angles to the strike) and sill pillars (which are oriented parallel to the strike) over the principal haulageway. In any case, development work gives service and supply, ore removal and access to a stope.

Chutes and box holes are replaced with a system of drawpoints spaced equally along the footwall of an orebody in trackless mining. These are developed so as to break into the ore at the level of the sill.