Slimes are treated in the Slime Plant|
At various stages in the dressing process, quality checks are carried out. This is done by VANNING: a small amount of the concentrate is put on a large vanning shovel and is then swirled round with clear water in a circular motion. A skilled vanner will soon see a line of the grey tin particles thrown up along the upper edge of the shovel and will be able to make an accurate estimate of the percentage of tin present. He can then make any slight adjustments to the machinery which may be necessary - for example, he might alter the tilt of one of the tables.
The final stage at Tolgus, a chemical check, or ASSAY, was done.
You often saw a white-coated figure in the Assay laboratory, absorbed with test tubes, their contents changing colour as if by magic.
The final assay should have corresponded closely with the one done at the smelters, for the price they paid for the tin was based on the percentage of pure tin in the concentrate
|History of Tolgus||Stream Tin & Lode Tin||Management & Workers||12-headed Cornish Stamp||Sulpher & Arsenic Waste Disposal.|
|Water Power||The Sand House||The Slime Plant. Assaying.||Smelting||Trevithick Trust|
|TOLGUS Tin streaming at Redruth|