Grenville United Mines, this is a page of two mines, Condurrow and Wheal Grenville. They both merged in 1906 to form the Grenville United Mines. Between them over the course of their lives they produced over 31,000 tons of Tin from working the Great Flat Lode. The mining group worked until 1921 when a crash in the Tin Prices forced closure.
The images on this page were taken during 1995 for use in Bob Acton’s book Exploring Cornish Mines Vol 2.
To reach the next site, walk over the road and up the hill to see the New Stamps Engine House.
On the site there is quite a rare survival. There is a wall that belonged to Frue Vanner House. The Frue vanner has a continuous rubber belt 4 feet wide and 27½ feet long passed over rollers to form the surface of an inclined plane on which the orestuff was concentrated. The belt travelled up hill at from 3 to 12 feet per minute while being laterally shaken about 180 to 200 times.
The inclination of the belt was from 4 to 12 in. per 12 feet. The belt received crushed orestuff from the stamps via a distributor about 4 feet from its upper end. As it travelled upwards, it met with small jets of water which gradually washed the gangue off the bottom of the belt.
As the belt travelled over the top roller with the heavier ore adhering to it, it passed into a box containing water where the ore was deposited. From 3 to 6 gallons per minute of water was required. One machine could treat 6 tons per 24 hours of stuff passing a 40 mesh screen.