In 2021 Cemex awarded MEP the contract to supply, design, deliver, construct and commission a new, fully operational, mineral washing and processing plant at the new Pyford Brook Quarry located near Alrewas, Staffordshire.
The quarry processes Trent Valley sand and gravel containing lignite throughout. MEP has resolved this problem at many sites producing clean, well graded, de-lignited sand to the levels required for this project.
MEP’s experience of supplying de-ligniting equipment for the Trent Valley goes back to the 1970’s when BCA first installed Hydrosizers to remove lignite from concrete sand.
To supply and install a bespoke 230 t/h sand and gravel plant, with the ability to process 300 t/h including re-crushed material. The plant is designed to produce 4 x 10 and 10 x 20 aggregates, both with 1000 t stockpiles and a washed concrete sand with lignite < 0.04% by weight with a 2000 t stockpile.
The primary gravel section consisting of feed hopper, belt feeder, cone crusher, a primary and secondary screen were subcontracted to Quarry Manufacturing & Supplies (QMS) with an MEP Hydrolig integrated into the primary process to remove coarse lignite before the MEP two-stage deligniting sand plant.
The Hydrolig is a variation of the TBS Hydrosizer, which is a hindered settling classifier that uses an upward current of water to separate materials by specific gravity. It is designed to handle material up to 40 mm, however at Pyford Brook it receives the < 20 mm fraction. The Hydrolig uses water and sand particles to create a natural media within the vessel of the tank. The lower density particles, such as sand and lignite, float to the surface and overflow to an MEP Sieve Bend which separates the coarse lignite from the water and sand. The heavier gravel sinks and is discharged through the spigot and falls by gravity to the QMS Secondary Screen and on to conveyors producing the 4 x 10 and 10 x 20 aggregates.
The MEP two-stage deligniting sand plant receives the < 4.00 mm material together with the water from the Hydrolig plant. The feed material and water report to the Primary Sump and are pumped to two Primary high-capacity Cyclones, which partially dewaters the material and removes some of the silts. The Primary Cyclone underflows report to the Primary TBS Hydrosizer.
The TBS Hydrosizer underflow discharges onto a Dewatering Screen to produce a concrete sand. The overflow, which contains lignite together with the finer sand, reports to a Sieve Bend. The Sieve Bend overflow passes by gravity to the Effluent Tank. The underflow reports to the
Secondary Sump, where it is pumped to a Secondary high capacity Cyclone, which discharges to a Secondary Hydrosizer. The Hydrosizer underflow discharges to the SDS Dewatering Screen, where it is dewatered and discharges to a QMS Radial Stockpile Conveyor. The overflow from the secondary Hydrosizer reports, by gravity, to the Effluent Tank.
David Hakes, Senior Project Manager for Cemex commented “The team at MEP have a proven track record working with this material and with Cemex, having installed a similar plant at our nearby Willington Quarry. Following numerous technical and commercial discussions we placed a contract with MEP. The plant is built to our continually improving standards for safety in operation and maintenance”.
Steve Slingo, Sales Manager at MEP commented “The new plant was designed to achieve clean well graded sand and gravel that has exceeded the customer’s expectations.
MEPs unparalleled expertise, experience and track record together with our desire to work with the customer at all levels to ensure the best possible outcome is industry leading.
MEP would also like to put on record a special thanks to our contractor team including Boast Site Services, Darren Lee Construction, Intelect Midlands and QMS for their work on the Pyford Brook project.
