Shire Oak Quarry up and running

"Powerscreen Washing Systems have recently installed a new sand plant at Tarmac’s Shire Oak Quarry near Walsall. Having previously processed the sand and gravel deposit using a conventional static plant, the decision to invest in a Powerscreen sand plant was based on the company’s success with similar contracts throughout the industry."

"Generally the Bunter deposit at Shire Oak comprises a 50/50 sand/gravel split, the sand fraction being very fine with around 30% passing the 300µm sieve and silt accounting for 7% of the raw material."

"The plant supplied by Powerscreen Washing has the capacity to produce 150 tonnes/h in addition to recirculated material from the crusher. The plant utilizes a Fines Master 120, which, with its combination of bucket-wheel and twin hydrocyclone sand-recovery systems, maximizes sand production by minimizing fine sand losses to the silt ponds."

"Sand and gravel is extracted from the face by a loading shovel and deposited into the feed hopper of a primary Powerscreen Commander 1400 12 x 5 twin-deck full rinser that washes the material and produces 0–3mm and 0–6mm sands (through a split bottom deck), a mid-size –20mm+6mm material and an oversize +20mm material. The sand slurry is piped to the Powerscreen Fines Master 120 where it is dewatered and the fines recovered and stockpiled using two T5032 conveyors."

"Oversize product from the primary screen is fed to an in-line Pegson 900 Autocone crusher, with the crushed material being recirculated on to the inclined feed conveyor of the primary Commander 1400 via a third T5032 conveyor. Mid-size material from the primary screen is scrubbed in a Powerscreen Powerscrub 120R to remove any remaining clay and fines, while any wood contaminates are floated off via sieve bends at the rear of the unit. "

"Clean stone from the Powerscrub 120R is fed to a secondary Commander 1400 12 x 5 part rinser, where it is rinsed and graded. This screen delivers two products from its twin-deck box, with material from both the top and bottom decks providing a 20–5mm product, while the bottom deck provides a 10mm product; to ensure some overrun a variety of modular mats are used on both decks to bring the 20–5mm product within the required specification."

"The new washing plant is now producing four grades of clean, high-quality aggregate: a building sand to BS 1200, a concrete sand to BS 882, 20–5mm and a 10mm single size."

"Powerscreen Washing also supplied the sequential start/ stop electrical control systems for the entire plant. Housed in an adjacent free-standing weather-proof module, the control centre is powered by a Caterpillar genset."