Portland stone mining
Perryfield mine
Operating in Perryfield quarry, the already exposed face allows us to mine directly into the whitbed, mid tier and roach limestone beds. This gives us access to over 680,000m³ of reserve with 2 portal entrances.
The main limestone bed we are extracting from mining is Perryfield whitbed. With further beds following on in a phased extraction, as we progress further into the reserves.
A Portland stone mining operation consists of extracting dimension stone from underground. Removing the excavation process, found in open cast quarrying, allows us to reach suitable stone. Mining lets us access future reserves whilst reducing our impact on the local community and environment.
Perryfield mine entrance portals
The mine is a natural continuation of the quarry floor. This allowed us to directly saw into the Perryfield quarry face to form our mine.
After each advance from cutting, our team rock bolt into the roof of the mine to ensure it is reinforced and stable.
Initial portal cutting
We have 2 portals into Perryfield mine. They control the air flow whilst providing a safe emergency exit for our staff whilst underground.
The second portal was opened using a specialist back cutting blade Fantini, which is the first to be used in the UK.
Pillars
As we progresses further into our mineral reserve pillars are left behind to form a roof support system.
The surrounding dimension stone from each pillar is extracted by our team and leaves road ways. Perryfield mine’s extraction ratio is 70% of usable stone with 30% remaining for pillars.
Advancing by cutting
Each Fantini mining machine will cut into the road way face 3 horizontals and up to 5 verticals depending on geology.
Our loading shovels then extract the Portland stone which can be sold to the market or drawn into our modern factory.