Hope Construction Materials has introduced claimed pioneering CDE Global washing plant technology at its greenfield quarry in county Bedfordshire, UK Guy Woodford reports.
The
While demonstrating Hope’s focus on sustainability and continuous improvement, the plant is enabling Black Cat Quarry to supply around 350,000tonnes/year of sand and gravel to use in concrete for various building and construction projects across south-east England.
Hope was clear from the outset in terms of the grading of materials it required, and CDE was said to be the chosen provider because of its ability to successfully configure a plant according to the company’s needs.
As a result, Hope, the UK’s leading independent supplier of cement, concrete, aggregates, with around 180 sites across England, Scotland and Wales, invested in a 225tonnes/hour sand and gravel washing plant comprised of the M2500 E4X mobile washing plant, a P3-42 ProGrade aggregate screen, three M1508 integrated stockpile conveyors and one R2008 radial stockpile conveyor.
Furthermore, Hope had a requirement for the plant to produce a 20/5mm gravel product without the need to bucket blend as well as the ability to produce single size gravels, removing the necessity for screen mat changes or other labour intensive processes. A radial stockpile conveyor was also required in order to increase the available stockpile space beneath to allow for up to 3,000 tonnes of concrete sand product.
Five different types of material outputs are produced by the CDE plant solution; a 0-1mm building sand, a 0-5mm concrete sand, a 10mm gravel, a 20mm gravel and a 40mm gravel. Additionally, the plant effectively handles and rejects oversize material in order to negate the need for Hope to manually access the plant to remove any material of this kind.
From the preliminary stages of the project, CDE worked closely with Hope in order to co-create a solution which would essentially meet and exceed the firm’s needs and requirements, and there were various strands to this process. Matt Bunting, general manager for CDE Global in the UK, said: “From the very beginning of the tender process, Hope Construction Materials was definitive in what it wanted to reap from the plant, right down to the types of output material, the rate of feed, the overall capacity and even the colour of the plant itself. As with all projects that we deliver, we made every effort to ensure that we had a full understanding of what was required to ensure that Hope was happy with the solutions that we were designing based on its specifications, and this was achieved through its close involvement at various stages throughout the process. Our plants are designed and configured for each individual client and input from the customer is crucial to enable us to ensure the best possible performance.”
Andrew Rollo, engineering manager for Hope Construction Materials, said: “Throughout the consultation process, we were heavily involved in the project. Representatives from Hope including myself, our quarry manager, Simon Bryant, and our health and safety manager, Gareth Sturges, visited a CDE installation at Smiths Bletchington, and we also paid a visit to CDE Headquarters in Northern Ireland for a design workshop and a tour of their factory.”
“We also had the opportunity to meet the Project Manager at an early stage and get an understanding of their methods of project delivery – this gave us a lot of confidence and confirmed that CDE was the correct choice for this project.”
Rollo added: “Black Cat Quarry became the company’s first new quarry development, securing high quality aggregates supply to the south-eastern UK market for the next few years. This directly supports our concrete business in the region and represents a significant step forward for the business.”
At the beginning of the process, the feed material enters the plant via a tipping grid directly into the feed conveyor which features an integrated belt weigher. This feature allows operatives to ascertain what level of material is being fed to the plant at certain intervals and acts as a signal in terms of whether or not an increase in feed material is necessary, ensuring optimum feed rates. “This allows us to make sure we are maximising production volumes for our customers which maximises the return on investment that our customers enjoy,” explains Bunting.
Once moved along the conveyor, the material is then transferred onto the first phase of the screening and dewatering phase through the ProGrade P2-75 double deck rinsing screen, designed to cope with the harshest of conditions. Individually controlled spray bars ensure the highest level of washing. The top deck apertures on the polyurethane screening mats allow for the screening and stockpiling of the oversize +40mm aggregate while the bottom deck apertures on the screening mats screen the -40mm material down onto a side conveyor for transferring onto a triple deck sizing screen. Three material outputs are produced. The top deck creates a stockpile of a 20-40mm aggregate, the middle deck creates a stockpile of a 10-20mm aggregate and the bottom deck of the triple rinsing screen produces and stockpiles a 5-10mm of aggregate.
Meanwhile, the loose sand fractions from the bottom of the double deck rinsing screen on the M2500 are sent through the sand pump and pumped through to the first cyclone on the wash plant before being sent to one side of the split deck rinsing screen for further dewatering. From here, the apertures on the deck filters the material which is discharged to the integrated M2500 stockpile conveyor before being transferred to a radial stockpile conveyor. The sand washing element is configured to allow a proportion of 0-1mm material to fall through the screen apertures and this is then pumped to the second cyclone before being discharged to the dewatering screen where a 0-1mm building sand is produced. “The feed material on this project contained a large proportion of material in the 0-1mm range so there was an opportunity to produce the additional 0-1mm building sand which also guaranteed that the concrete sand was produced to the required specification,” explains CDE project manager on this project, John Gallery.
Rollo, of Hope, continued: “As well as their expertise, CDE were the chosen providers due to their ability to offer shorter lead times in terms of project delivery. This was essential, given the tight timeframe we were working within. Furthermore, the performance guarantees which were offered have given us an extra level of confidence in the plant’s ability to perform consistently and to the optimum level for maximum productivity.”
Following the installation and commissioning of the plant, the focus switched from the Project Management team over to the CDE CustomCare team to ensure that the plant operates to its maximum capacity. The remote team of engineers ensured that all training requirements of Hope’s on-site team were met to ensure a productive and safe plant operation. A range of CustomCare preventative maintenance programmes were also on offer to ensure that operations continue to perform consistently at the highest level possible.
Martin Jackson, CDE Global CustomCare manager, said: “Hope Construction Materials will be able to avail of an exclusive suite of aftersales services including training programmes, preventative maintenance inspections, a range of warranties and a full range of plant parts as and when required, and this service is exclusive to all CDE customers to ensure that their plant continues to generate operational efficiencies and a solid return on investment.”
