Cornish Metals Inc has started pumping the first water in a quarter of a century using two submersible pumps in New Cook’s Kitchen shaft from South Crofty tin mine.
TREATMENT PLANT
Two KSB BSX 463/5 specialist high-head 950 kilowatt vertical submersible pumps, manufactured and supplied by KSB Ltd, sit approximately 360m below surface.
The pumps are controlled by two Schneider Electric Altivar ATV 1200 variable speed drives supplied through Siemag Tecberg UK.
Cornish Metals said that the VSDs maintain the permitted 25,000m3 per day pumping rate to the mine water treatment plant as the water level in the shaft drops and the pumping head increases.
Teams from the Canadian company, Siemag Tecberg and Schneider Electric have been on site for the past two weeks testing the pumps and VSDs.
“The two pumps and both VSDs have now been successfully commissioned and run through a series of performance tests to demonstrate their ability to meet the target flow rate to the MWTP [mine water treatment plant],” added Cornish Metals in a statement.
“The pumps have been pumping mine water from below the 195 fathom level to the MWTP where it has been diverted around the plant and returned back underground via a specially installed commissioning loop.
“Once the MWTP is completed and commissioned later in the summer, the fully treated mine water will be diverted to the Red River and dewatering of the mine will commence.”
Chief executive officer Richard Williams described the commissioning as a very significant milestone for South Crofty.
“Seeing the first water being pumped out of the mine during this commissioning phase since the mine’s closure 25 years ago is a truly historic moment.
“Our project team has worked extremely hard to instal and commission the pumps and drives safely and efficiently.
“We have also been supported by a small army of dedicated local contractors along with equipment manufacturers and suppliers, so a big thank you to everyone involved in the project to date.”