Grundon - Kennetholme Quarry

The prime objective of the new wash plant is to process ‘as-dug' material in a replacement for the existing Grundon operation at the nearby Padworth Quarry where mineral processing will soon cease.

Kennetholme has over 10 years of reserves of a flint based sand and gravel. The new plant site was originally an old paper mill works. Some of the old infrastructure has proved useful for the new plant installation, with the old water treatment system being brought into service for water storage and an old concrete structure utilised as a supporting wall for the hopper feed ramp.

Founded as a minerals company by Steven Grundon in 1929, Grundon is now the largest privately owned waste management group in the UK. As a family owned company, Grundon is well respected nationally for its professionalism and is acknowledged to be in the vanguard of waste management practice and innovation.
Production process.

After site survey and consultations DUO (Europe) supplied a plant capable of processing material at 150 tph, producing the required products of sharp sand, 10mm, 20mm, 40mm and +40mm oversize.

Material is fed via either dumptruck or loading shovel into a 30 ton capacity feed hopper which is fitted with a remote control tipping grid (4" grid spacing) and variable speed drag out belt. All +125mm oversize material is rejected to ground whilst the -125mm material is fed onto a 24 metre long inclined troughed belt feed conveyor.

From here the -125mm material is fed onto a 16 x 5 double deck rinsing screen. Any material greater than 40mm is rejected and sent to stockpile via a conveyor; whilst all -40mm material is fed to a Powerscreen Logwasher. Featuring twin shafts with interchangeable high tensile blades, a built in agitation system excites smaller particles causing them to float and in turn discharge via the water exits. The Powerscrub is fitted with an elevated spray bar which constantly adds water which washes the material and encourages lighter particles to float through the water exit.

Material then passes over an 8 x 4 dewatering screen fitted with polyurethane modules and is then conveyed via a 20 metre transfer conveyor to a 12 x 5 double deck dry screen. This dry screen grades the material into three sizes of 10mm, 20mm, and 40mm which are conveyed and stocked by three further 20 metre long stockpile conveyors.

All waste water from the Powerscrub is then sent over a 6 x 2 dewatering trash screen fitted with polyurethane modules where all foreign materials are removed from the system and fed into a skip, with the water and sand gravity flowing into an adjacent Powerscreen Finesmaster.

The Fines Master 120 compact sand plant incorporates a rubber lined Linatex cyclone with fixed spigot and a rubber lined Linatex centrifugal pump. The system has a self regulating collection sump with built in float system. The underflow from the cyclone is discharged onto a high frequency dewatering screen fitted with polyurethane modules and adjustable vibrating motors.

The dewatered sand from the Fines Master is then delivered to stockpile via a radial sand conveyor. The waste water from the sand classification unit is then pumped into a nearby lagoon.

Ken Branigan, Aggregates General Manager commenting on the project said, "Duo installed the plant in a very efficient and professional manner, paying specific attention to Health and Safety. I would have no problem recommending Duo and their products to anyone"

"At Grundon, we currently operate eight quarries across Southern England - producing a wide range of products for a wide variety of customers. Our core aggregate business is the supply of sands and aggregates to the building, construction, landscaping, decorative, and leisure markets".
"We offer a unique "open door" policy as we actively encourage the general public, smaller builders, landscapers and DIY enthusiasts to come along and purchase directly from our quarry weighbridge offices - no matter how little product is required".

"With our huge emphasis on customer care and our commitment to high standards, we are energetically committed to minimising the environmental impact of all our operations and services. Our commitment to quality of service and technological progress is allied to a real and demonstrable concern for the environment".