Hope Construction Materials open first new greenfield quarry with a washing plant from CDE

The UK’s leading independent construction materials supplier has recently demonstrated its commitment to sustainability and continuous improvement with the installation of a new modular washing plant from materials washing specialist CDE Global. In March 2014, Hope Construction Materials acquired their first washing plant in the company’s short history in order to bolster sand and gravel supplies into the South East of England and enhance efficiencies in their concrete production.

‘Black Cat’ Quarry near Roxton in Bedfordshire will supply more than 100,000 tonnes of sand and gravel each year to use in concrete for various building and construction projects across the south east of England.

As the country’s leading independent supplier of cement, concrete, aggregates and with around 180 sites across England, Scotland and Wales, Hope were clear from the outset in terms of the grading of materials that they required, and CDE were the chosen providers because of their ability to successfully configure a plant according to their specific needs.

As a result, Hope invested in a 225 tph sand and gravel washing plant comprised of an 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 3000 tonnes of concrete sand product.   

Five different types of material outputs are produced; 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.  

All of these requirements resulted in the installation of an M2500 E4X mobile washing plant, the world’s first integrated mobile washing plant which offers, feeding, screening, sand washing and stockpiling on one compact, portable chassis, offering minimal footprint and rapid deployment.

The co-creation approach to plant delivery

From the preliminary stages of the project, CDE worked closely with the company in order to co-create a solution which would essentially meet and exceed their needs and requirements and there were various strands to this process.  Matt Bunting, General Manager for CDE Global in the UK, comments,  “From the very beginning of the tender process, Hope Construction Materials were very definitive in what they 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 their specifications and this was achieved through their 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 highlights, "Throughout the  consultation process, we were heavily involved in the project.  Representatives from Hope including myself, our Quarry Manager and our Health & Safety Manager 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 got the opportunity to meet the Project Manager and get an understanding of their project delivery – this gave us a lot of confidence and we knew that CDE was the correct choice."

Andrew continues, “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."

The Processing System

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 to make sure we are maximising production volumes for our customers which maximises the return on investment that our customers enjoy” explains Matt 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 M2500 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 John Gallery the CDE Project Manager. Andrew Rollo of Hope Construction Material also comments, "As well as their expertise, CDE were the chosen providers due to their ability to offer shorter lead times in terms of project delivery and 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."

Post Commissioning Support

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, Global CustomCare Manager comments ‘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’. 

Hope Construction Materials is Britain’s leading independent producer of concrete, aggregates and cement, employing 900 people who between them have extensive knowledge, experience and determination to provide a fresh alternative in the heavy materials sector.