 |
|
Earlier this year one of Bardon Aggregate's newest sand and gravel operations came on-stream. Uttoxeter Quarry is located in the heart of rural England, close to the Staffordshire / Derbyshire border. The site is being developed on 100ha of Greenfield land in the Dove valley.
Geological investigations at the site have identified potential reserves of approximately 4.7 million tonnes of saleable sand and gravel. The depth ranging between 1.5m and 8.5m. Compositionally it comprises 6% silt, 30% sand and 64% gravel, the latter being predominantly quartzitic in nature. The sand and gravel is underlain by a layer of alluvium, which overlies the Mercia mudstone group.
Bardon Aggregates plan to work the deposit in 12 phases over a period of 12 years, with each 12-month phase yielding around 4000,00 tonnes of material. The quarry has been established primarily to supply concrete aggregates to outlets within the business in the Midlands region.
On arrival at the plant the material is discharged from the field conveyor into a 20 tonnes capacity Finlay plant feed hopper equipped with a sloping reject grid with bars set at a spacing of 150mm. A reversible belt feeder mounted beneath the hopper allows the sand and gravel to be either sent on for further processing or fed to an adjacent as-raised stockpile which provides a supplementary raw material supply in the event of serious flooding in the working area.
| |
 |
From the plant feed copper, a 27m long inclined static conveyor, fitted with a 750mm wide belt and equipped with a Beckford belt weigher at the tail end, delivers the material to the first screen. This comprises a 20ft x 5ft twin-deck Finlay washing screen fitted with polyurethane panels and rubber-lined chutework. The screen's top deck removes any +75mm material, which is fed to an adjacent oversize stockpile by means of a short side conveyor.
|
-3.5mm material is washed through the lower deck and fed by a flume arrangement to a variable-speed electric/hydraulic Finlay 200E Hydrasander for dewatering. The -3.5mm sharp sand discharged from the Hyrdrasander is delivered to stockpile by a 24m long x 750mm wide Finlay 830 mobile stockpile conveyor with a powered hub for 120° radial movement.
|
 |
 |
The middle product from the first screen is discharged directly into a Finlay 206 logwasher which is powered by a 45kW electric motor and offers an adjustable angle of slope from 4° to 10°. Any sand liberated by the log washer is once again flumed to the Hydrasander, while the coarser fraction is discharged directly on to a 17m long transfer conveyor for delivery to the second screen
|
The second screen comprises a 20ft x 5ft twin-deck Finlay rinsing screen, the first 4ft of which is fitted with spray bars while the remainder of the units is dry.
Once again, any residual sand liberated by the rising action is flumed away to the Hydrasander. The Uttoxeter plant has a total water requirement (Hydrasander, spray bars etc) of 1,200 gal/min, which is met entirely by the recirculation of process water through two 100m x 90m lagoons.
|
 |
|
|
The quarry's remaining final products (-20mm + 5mm and 8mm single size) are sized on this screen and delivered to stockpiles by a Finlay 830 mobile/radial stockpiler and a 24m long static conveyor respectively. Meanwhile the -75mm + 20mm oversize from the top deck of the second screen is fed on to a 24m long x 750mm wide chevron conveyor for delivery to a 20-tonne crusher surge hopper
|
|
