Wheal Jane Group is based on the site of Wheal Jane Mine which closed in 1991. The Processing Mill here continued to work processing South Crofty’s ore until the closure in 1998. The mill then lay idle until it was demolished, by 2014 all remains of the plant had been removed from the site.
In January 1992 after the mine had flooded the plug failed on the main mine adit. This caused the release of over 10 million gallons of contaminated mine water to enter the Carnon River and flow to Falmouth Bay.
The water was contaminated with Cadmium, Zinc, Arsenic and Iron. Due to the reaction of the water with the salt water of the sea caused the appearance of a red sludge which caused significant environmental problems.
Consequently a temporary treatment plant was constructed by the Environment Agency in 1992. During the years that followed this has evolved into a plant that treats 500 million litres of water every month.
The process is quick and simple. Seven electric pumps are suspended in Wheal Jane’s No2 shaft just above the adit level which is at 60m depth. These raise up to 330 litres a second up the shaft to the plant, this is dependent on the level of the water.
The rest of the mine site is now occupied by the Wheal Jane Group who have a long term vision to covert the site into a sustainable business park. Many of the old mine building have been adapted for use for the seven companies and 120 staff that now work on site.
A Solar farm which covers 7.2 acres has recently been built. There are plans for Hydo, Wind and Geothermal plants which will contribute to the reduction of the carbon footprint. There is also a large laboratory which analyses mineral samples from all over the world which was very interesting to see.
The following images are taken in and around the treatment area. Firstly, Hydrated Lime is added in the Reaction Chamber to raise the pH of the water and to assist the precipitation of the suspended Iron.
This in turn colours the water a deep red. After mixing the water is pumped to the Clarifiers, here a liquid chemical polymer is added which helps bind together all the solids in the water. As a result, these quickly settle at the bottom of the tank, and the now clear water is pumped into Clemows Stream.
The remaining sluge is pumped to the Tailings Dam where eventually it will be covered by soil and landscaped. The plant is now run by Veolia Water, my thanks to Nigel who gave up his time to show me around.
It was sad the day was not better for photography, the next few photographs were taken whilst wandering around the old site.
Finally, at the end of the tour I was asked if I wanted to see a “melt”. I jumped at the chance, it was only a small furnace but well worth seeing.
When the mill was demolished a large amount of Tin concentrate was salvaged. So I was watching South Crofty Tin, which I thought was very fitting.