Breaking Ore Underground

A miner’s job was to extract the ore that contained valuable metals from deep underground. To get to the lodes containing the ore, they first had to dig shafts or tunnels to reach it. But how did they manage to break the ore from the hard rock and what tools did they use to do it?

 

Getting the valuable copper or tin ore of the rock was a difficult and often hazardous process. The rock had to be broken, either by hand, gunpowder, or later with dynamite or other high explosive.  As Cornish mines became deeper, the mine workers’ job became more dangerous – with an increased risk of falling from the many ladders in use, collapsing rock, or flooding. 

Separating the ore from the rock

Mining today owes much to 19th century Cornish miners, who pioneered new tools and methods for extracting ore.

Miners used a variety of tools to extract the ore, including hammers, borers (chisels) and gads (wedges).  From the 1880s, they also used air-powered rock drills to increasing effect.

The productive area of the lode being exploited is known as the stope. The most effective way of extracting the ore was to drill holes, called ‘shot holes’, into the rock and introduce gunpowder into the hole. When suitably stemmed (packed) a safety fuse would be inserted then lit, and the resulting explosion would break the rock apart. The fuses would be lit in sequence, if driving a level (tunnel), to ensure the rock would break out to the full width and height required.

There were two main problems for miners: removing large volumes of water from deep workings, and the hardness of the rock to be broken.

Blasting was usually done at the end of a shift, so that the fumes had chance to clear before the next gang arrived to load the ore ready for hoisting to surface.  Over-sized ore would be broken manually to a size suitable for loading into kibbles and later skips, used for hauling. Once above ground, surface workers started the process of dressing the ore.

Learn more ...

Geology: Earth Treasures

Geology: How Minerals Form

Inventions: Drills

Mining Processes: Haulage and Transportation

Mining Processes: Dressing the Ore