Dernaseer supply & install a new wash plant for Acheson + Glover at Crievehill Quarry, Co. Tyrone

Based in Dungannon, Co. Tyrone Dernaseer was established in 1988 and has grown to be a leading manufacturer of washing plant systems for the sand and aggregate and C & D recycling industries. The company has installed equipment throughout the world including Ireland, UK, Latvia, Russia, Sweden, Norway, Spain, Columbia, Chile, Belgium, Bahrain, Trinidad, Lithuania, Romania, Poland, Bulgaria, Morocco, Australia, and USA

The company’s founder and Managing Director Declan McKenna leads a team whose combined experience of both engineering and washing applications ensures a quality plant which is designed, manufactured and installed to the highest standard. All their plant is designed and constructed with the latest health and safety, maintenance and environmental issues in mind.

We met with Martin Conway, Sales & Marketing Director of Dernaseer who told us more about the company “Business is extremely buoyant for us globally and we have recently invested heavily in a brand new 38,000sq ft (3,500m2) production facility which will open in January 2019 allowing us to double our production capacity. Dernaseer can supply a single piece of equipment or a fully turnkey washing system anywhere in the world. Our services include plant design, manufacture and supply of equipment, electrical control systems, shipping and on-site installation. As well as offering new installations Dernaseer’s extensive knowledge and expertise in the aggregate washing industry enables us to quickly identify and solve problem areas in existing plants, whether the customer needs increased production, improved grading, cleaner products or if they need to add a new product grade.

We then accompanied Martin to visit Declan McStravick, Works Manager at Acheson + Glover’s (AG) head office at Crievehill Quarry, Fivemiletown, Co. Tyrone to  look at one of their latest bespoke wash plant installations. Declan explained “We manufacture all types of concrete products across multiple sites in Northern Ireland, and this site is our head office where we have a working quarry and sand pit, and it’s from here we supply all the aggregates to the rest of the AG group. We have a limestone deposit here with primary, secondary, and tertiary crushing and screening and we also have a deposit which is fairly contaminated with clay and silt. We produce a dirty crusher run daily which has also been building in large quantities since the quarry started. This is where Dernaseer got involved to come up with a wash plant solution for us to take the dirty fraction of our primary material and wash it to give us further aggregate that we can put into our concrete products. This washing plant is going to allow us to now recycle that previously waste product which is a huge opportunity for us and we are very happy with the plant, its working very well, and we have a great partnership with Dernaseer.”

Martin explained a little more about the plant “With a feed material of crushed dirty limestone, this bespoke wash plant consists of a 40m3 variable speed belt feed hopper fitted with a remote-control tipping grid which is fed by a Volvo dump truck. The 0-120mm material which passes through the grid is then delivered onto the main inclined conveyor which feeds all the material into a 7m x 2.5m rubber-lined scrubber barrel. The scrubber barrel is the most effective solution for the difficult feed material in this quarry as it accepts an all-in feed removing the need to separate fines first and it can handle much larger particles than a log washer.

“The scrubbed material is discharged onto a 6m x 1.83m three deck washing screen which utilises eight individually controlled spray bars on each deck. The screen is fitted with polyurethane screen media on all decks. The top deck scalps off any material above 15mm which is fed by conveyor to a Hazemag horizontal impact crusher. The crushed material is returned to the washing screen by conveyor. A split bottom deck, 3mm and 5mm, with rubber-lined catch-box, provides the feed to the cyclone sand plants to produce the required two sands. The +5-15mm is fed by conveyor to a 5m x 1.8 screen to separate the three required aggregate sizes. All chute-work on the plant employs a dead-box system which results in a rock on rock set-up providing excellent wear properties.

“The water treatment system at Crievehill receives dirty water, from the washing plant and has two purposes. Firstly, the water is clarified and recycled the water and secondly the sludge is concentrated in preparation for further pressing. The dirty water coming from the cyclone overflows are mixed with a polymer flocculent solution and fed into the thickener tank. The sludge settles quickly at the bottom of the thickener where it is concentrated and gathered into the pumping cone due to the slow movement of a scraper inside the tank. The concentrated sludge is then pumped into a mud buffer tank which homogenises the sludge before being pumped to a Matec 2000 x 1500 x 140 filter press where it is pressed to produce a dry cake. The water from the pressed sludge is recycled to the washing plant. The clean overflow water from the thickener tank is discharged into the clarified water storage tank, where the water pump delivers it back to the washing plant. The finished products are 3mm sand, 5mm sand, 6-9mm, 10-12mm, 13-15mm with all +15mm going back to the crusher and returned to the washing screen for re-processing.”

For more information on wash plants and other products from Dernaseer please visit www.dernaseer.com or call Martin Conway on +44 (0) 28 8776 7646

Associated Businesses

  • BT70 3BW