RE: Southwestener - Thank you.17 Mar 2021 16:25
How much copper has been mined in Cornwall in tge last 100 years - pretty much zero, Cornwall pretty much stopped producing copper by the end of the 19th century.
The biggest problem with copper ore was benefication - the stuff being pulled out of the ground at the end of the 18th century was grading around 12-15Cu, and that was hand sorted and sent for smelting, as the grade dropped there was no way of processing it to increase the concentrate grade and mining switched to tin which was found at depth.
At the beginning of the 20th century froth flotation was developed which enabled the copper ore to be concentrated, but by that stage there were far cheaper sources of the metal.
Wheal Jane was a truly polymetallic mine as opposed to a tin mine, it produced 3 times as much zinc as it did tin, it also produce a significant amount of copper as well as silver - croftys mill was essentially a gravity mill while janes was principally a flotation mill. As a result Janes copper production was pretty much the only copper produced in Cornwall in the last 100 years.