History
Devon Quarry is located in North East Fife approximately 1 mile north of the village of Kennoway. Quarrying operations began at Devon in the mid 1930's and continued until the mid 1960's when the quarry closed. In 1977 the quarry was re-opened as a landfill site only, to allow the void space to be filled in and restored to its original condition. In 2000 the Skene Group re-opened the quarry and commenced crushing operations in late 2001.


Geology
The rock extracted from Devon Quarry is a Gabro, which is part of the Gabro Rock Group. This is a particularly unique rock which having a high crushing strength, low shrinkage value and a high resistance to polishing (PSV 67) makes ideal for high specification concretes and road surfaces used in motorways and airport runways.



The following processes have to be followed in the production of finished quarry materials.


Stripping
To gain initial access to the rock any soil, subsoil and any other types of soft dirty material, which covers the top of the rock, must first be removed. This is called stripping or "muck shifting" and is usually carried out with large excavators and wheeled loading shovels. This material is then used to landscape or screen the quarry or is stored for restoration uses at a later date.


Drilling & Blasting
With the top of the rock surface now clean and levelled off it can now be drilled in preparation for blasting of the rock face. The rock drilling is carried out by a pneumatically powered drill rig, which traverses on caterpillar type tracks. This machine drives drill tubes vertically into the rock face to a pre-determined depth and angle. These drill holes are equally spaced apart in single, double or treble rows of some 10-20 holes.

These drill holes are then carefully loaded with sausage type explosive pills which can only be detonated with a high electrical current in a controlled and safe manner. This blast can release up to 25,000 tonne of large boulder-sized rocks.


Types of Mobile Plant Used

 Volvo Loading Shovel

 Volvo 36 tonne Excavator


Primary & Secondary Crushing
These large boulder-sized rocks are then lifted by the face excavator and cast into the primary crusher where they are crushed between two large steel jaws into smaller stones prior to being conveyed into the secondary cone crusher which again further reduces the size of stone. This primary & secondary crushing process reduces the boulder-sized rocks down to rocks the size of a tennis ball.


Tertiary Crushing and Screening
This tennis ball sized rock is then lifted by a loading shovel and processed through a smaller cone crusher which reduces the rock to its finished product sizes. This smaller crushed material is then passed over a series of screens which segregate them into the individual sizes of 40mm, 28mm, 20mm, 14mm, 10mm, 6mm and whin dust.


Product Uses
These single sized aggregates or blends of such are used in the manufacture of concrete, tarmac, building blocks, bricks, roof tiles, slabs which are all key constituents in the building of roads, railways, airports, hospitals and houses e