Fine Sand | Coarse Sand | Filter Cake
The C&D waste recycling plant installed by CDE for Derwen Construction was the first of its kind in Wales and offers a viable alternative to waste disposal at landfill sites.
The majority of the feedstock at Derwen originates from Greenfield excavations and rock overburden; normally sent to landfills. This material is now processed by the CDE plant at a rate of 150tph, producing high quality, washed, sustainable, certified aggregates which conform to British and European standards; contributing towards minimising waste to landfill, and meeting ever increasing landfill division targets.
Variable feed working in close conjunction with Derwen Construction throughout every stage CDE designed a system capable of managing the widely varied feed stock associated with construction and demolition waste. On this project the highly variable feed gets fed onto a vibrating head, mounted over the feed hopper by shovel, removing any oversize material. This then passes through the integrated CDE hopper-conveyor - correctly aligned during manufacture, thus reducing spillage and the time required for installation and house keeping.
The inclined conveyor, fitted with an over-band magnet removes any ferrous material and feeds directly into the ‘R2M60’ 1.5x4m Rinsing Screen, which washes out the -4mm material. This -4mm material then travels directly to the CDE Dual Sands Plant and is washed using an integrated hydrocylone, removing silts and clays. The Dual Sand Plant will produce approximately 80tph fine sand and coarse sand, dewatered to typically less than 13% moisture content.
Maximum water recycling
The waste water is sent for treatment firstly to a A600 High-Rate Thickener with its integrated polyelectrolyte dosing station. A thick sludge is quickly formed and pumped to a sludge holding tank fitted with agitators. A CDE / Diemme GHT Filter Press is then used for maximum water recycling. The GHT is a heavy-duty machine that has been well proven and is trusted in numerous installations throughout the world. Its cake dryness of c80% results in easy handling and reduced transport costs, while the low cycle time results in reduced maintenance. Further to this no flocculent or lime is required to be added significantly reducing long term costs.