Six Powerscreen Crushing and Screening Plants Work in Tandem at Limestone Quarry

Willowtree Site Services, established in 2001 and based in the north-east of England, is a contract crushing and screening specialist which is in partnership at Coxhoe Quarry in County Durham with owners and operators Hope Construction Materials, Britain’s leading independent producer of cement, concrete and aggregates.

Willowtree has been a Blue Machinery Scotland customer since the company bought its first Powerscreen rinser a couple of years ago and, during the past few months, Willowtree has made a major investment with Blue purchasing six Powerscreen crushing and screening plants. These productive, crawler-mounted, mobile machines are now working the top bench at Hope’s Coxhoe Quarry, crushing, screening and stockpiling around 350,000 tonnes a year of size-specified limestone aggregates and agricultural lime.

The Powerscreen set-up at Coxhoe is comprised of a Premiertrak 400 jaw and 1000 Maxtrak cone crusher, three Chieftain 2100X and one Warrior 1800 screening plants. Working largely in tandem, the Powerscreen array is producing 10mm, 14mm and 20mm aggregates and 20mm+ oversize from the quarried stone for the civil engineering and construction markets, plus 4mm lime for soil enhancement for agriculture. The initial contract for Willowtree Site Services is for two years with potential for extending this further.

The high capacity Powerscreen Chieftain 2100X and Warrior 1800 screening plants are well-established and site proven machines with output potentials up to 600 and 400 tonnes per hour respectively which, of course, depends on feed size, mesh size and material type. Agile and mobile on site, with heavy-duty crawler tracks and a removable pendant remote control system, both models have quick set-up times, easily accessible engines and screen media for maintenance convenience and screen changes, hydraulically folding conveyors and high-performance hydraulics for optimum output. Both Warrior and Chieftain models are equally at home screening and stockpiling aggregates, blasted rock, recyclables and mined materials such as processed ores and minerals.

The 1000 Maxtrak cone crusher can accept an ‘all in’ feed, thereby eliminating the need for pre-screening which would reduce the cubicity of the finished product.   The feed hopper is equipped with a level probe which maintains choke feeding of the cone crusher, improving cubical shape and increasing fines production for ‘road-base’ applications.   The taper roller bearing design, with hydraulic setting, tramp release and unblocking system, ensures excellent productivity and ease of operation. Dust suppression sprays are included as standard to reduce environmental emissions. Adjustment can be made ‘on the run’ using touch button controls with direct read-out of closed side setting.

The Premiertrak 400 pre-screen jaw crusher incorporates a fully independent high amplitude, hydraulically driven pre-screen with increased drop angle on the bottom deck to facilitate maximum throughput and capacity. Improved pre-screened material flow is achieved by an enlarged discharge opening from the under chute which allows faster movement of pre-screened material to bypass the crushing chamber.

Commenting on the Powerscreen machines, Willowtree’s founder and owner James McLeod said “We looked at the available equipment on the market and closely consulted our customer’s highly experienced quarry manager at Coxhoe and we both came to the conclusion that the Powerscreen products would be best for the job in hand. Also, we at Willowtree have enjoyed an excellent relationship with Blue Machinery Scotland and this, combined with the reputation, build quality and productivity of the Powerscreen machines, made our choice easy”.

www.bluegroup.co.uk