Key Stages in the Mining Process
From finding the right location to dressing and smelting the ore, there was much more to mining than just what happened underground. The mining process was complex, with several stages. So what came first and how did it all work?
There were six main stages in the Cornish mining process:
Skilled mine workers who could judge the quality of the lode were much sought after.
Skilled workers with geological knowledge could identify an area where a particular ore was likely to be present by analysing the composition of the rock in the area and surface mining activity such as streamworks nearby. If it looked promising, small-scale exploratory shafts might be sunk to confirm the area’s promise. Setting up a new mine was an expensive business, so skill and experience were important to maximise the chances of striking a profitable ore body.
2. Reaching the ore
While ore could sometimes be found on the surface in small amounts, larger lodes – or veins of metal ore in the rock – were found deep underground. To reach them, miners had to dig levels (tunnels) and sink shafts into the ground.
3. Breaking the ore underground
Extracting the ore from the rock was an arduous and sometimes dangerous process. Miners used a variety of hand tools – including hammers, borers (chisels) and gads (wedges) – as well as gunpowder, and later dynamite or other high explosives, to break the rock up and free the ore.
4. Bringing the ore to the surface
Depending on the extent of the mine, and where the ore was located, ore could be brought up to the surface using a hand operated windlass (winch) or by using a more mechanised winding device such as a horse whim (winch) or that driven by a water wheel. As mining technology developed, steam powered beam whims were constructed to do this, later to be superseded by horizontal steam winders.
Mining was a family occupation, with women and children working on the surface dressing the ore.
5. Dressing the ore
Once the ore had been brought up from underground, it needed to be dressed, or processed ready for smelting. Women (known as ‘bal maidens’) and children did the majority of this work, particularly on copper mines, but men were also employed to perform some of the heavier ore dressing tasks.
6. Smelting the ore
To extract the metal from the ore, it needed to be smelted. Most ores are a chemical compound of metal with other elements, like oxygen or sulphur. Smelting uses heat and a reducing agent, like charcoal, to remove these other elements from the metal.