Washing Plant Produces Recycled Aggregates to Specification
Thursday, October 18th, 2007
Raymond Brown Group recently formed Raymond Brown Minerals & Recycling Limited specifically to focus the related businesses within the company. Their operation at the Rookery Farm Landfill and Recycling site, close to Swanwick near Fareham in Hampshire has recently seen the design, construction and commissioning of a modern, ecologically and environmentally friendly washing plant, supplied by Blue Machinery Southern. Based on Powerscreen equipment working in tandem, with a highly specialist silt management system from Haith Industrial, Raymond Brownâ€™s new washing plant is now producing high quality clean aggregates and clays to specification and, significantly, has already made considerable reductions in water usage, settlement pond maintenance, wasteful and costly landfill tipping.
Landfilling at Rookery Farm, first started in the 1980â€™s, with recycling on the site beginning in 1995 by crushing and screening concrete. In 2002, a pilot washing plant was installed to develop the production of clean recycled aggregates. The limited silt recovery system at that time required large volumes of water and, when considering a new and more sophisticated washing plant for the site, Raymond Brown focussed on enhanced silt recovery to produce quality clays as well and to effect a major reduction in water wastage. Additionally, a key element for the new plant was to achieve a long-term planning life of at least 15 years to justify the investment. The new plant supplied and installed by Blue Machinery Southern is not only capable of attaining Raymond Brownâ€™s target of 65,000 tonnes output of aggregate per annum, plus silts and clays, but has also already significantly reduced water consumption. Raymond Brown Minerals & Recycling Ltd reports that the new plant is now fully operational and meeting their high expectations.
Rookery Farm is ideally located for both sourcing raw materials from the surrounding area and easily reaching the markets for the clean and high quality recycled aggregates and clays produced. In developing and investing in the Rookery Farm plant, Brownâ€™s had to meet stringent planning controls, paying particular attention to impact on local residents, ecological considerations, highways and traffic, noise and dust reductions and landscape.
Steve Cole, Environmental & Development Director for Raymond Brown Minerals & Recycling Ltd comments; â€œWe undertook a major revision of the site layout, constructed an internal acoustic screening bund around the washing plant, increased other screening bunds around the site, all now planted with trees and re-routed transport away from sensitive boundaries to reduce the siteâ€™s impact in the surrounding area and the washing plant is powered by a fully sound-insulated generator systemâ€. Steve continues, â€œBlue Machinery Southern came up with a strong proposal and, coupled with our already excellent and long-standing relationship with the company and the build quality of the Powerscreen equipment they distribute, our choice was obviousâ€. Steve concludes â€œWeâ€™re looking to move recycling up the value chain and our new plant at Rookery Farm is helping us to achieve this very satisfactorily!â€
Recycled materials now being produced at Rookery Farm include concreting sand, a range of aggregates for pipe bedding, drainage, and low-strength concrete, as well as the bulkâ€“fill crushed concrete materials for capping and sub base. The silt cake produced by the Haith Industrial silt management system is still being assessed and tested for a variety of potential uses which include puddle clay for canal and river bank work, landfill capping and also as a soil base with blended compost materials.
The Powerscreen Washing plant
A series of Powerscreen machines work in tandem, starting with a Commander 1400 belt feeder with vibrating grid fitted with 60mm heavy-duty fingers. A 6532 feed conveyor is equipped with an overband magnet to remove any contaminating ferrous metals. An 8X4 double-deck rinsing plant removes the 0-5mm sand and +40mm oversize. The Powerscreen 120 Log Washer is fitted with a trash screen which removes light waste, wood and plastic, from the aggregates and also has a wash deck which gives the 5mm-40mm products a final rinse. Next, a Powerscreen 5032 conveyor takes the aggregates to the final 10X5 screen which splits the material into 5mm-10mm, 10mm-20mm and 20mm-40mm with three conveyors stockpiling the different products. The sand is processed through a Powerscreen Finesmaster 60 which dewaters this material prior to stockpiling via another conveyor.
The Haith Silt Management System
This sophisticated water treatment system is comprised of a thickener tank with automatic flocculation, a polyelectrolyte dosing station, a sludge stocking tank with sludge pump and a Haith overbeam filter press with 1500mmX1500mm plates for cake production. A clarified water tank with a water pump feeds cleaned, recycled water back to the washing plant. The installation is powered by a 500kVA generator supplied by Woodlands Generators of Evesham and the central control system for the entire plant has a PLC electric control panel located in a lockable steel container.
Overall, this new washing plant has vastly reduced water consumption and settlement pond maintenance through recycling and with the addition of ground level tanks which collect spillage water and rainfall. Raymond Brown Minerals & Recycling reports that the site is now 90-95% water self sufficient.
All civil engineering at Rookery Farm was undertaken by Raymond Brown Construction Limited and the project benefited from a grant from the Waste Resources Action Programme (WRAP) under the Capital Grant Scheme based on a five year performance agreement. The landfill operations at Rookery Farm are deferred until recycling ceases.
For further information visit: www.bluemachinery.com