Metso crushers help safeguard national asset
A FULL line-up of Metso Minerals crushing and screening equipment is being used to provide the Isle of Man with much-needed roadstone and asphalt products. Owned and operated by the Works Division of the Isle of Man Government’s Department of Transport, the Metso equipment forms the lynchpin in production at Poortown Quarry, near Peel, and represents part of a £7 million redevelopment of the site.
Measuring approximately 30ha in size, Poortown is now the only quarry on the island producing roadstone. The site currently produces 70,000 tonnes per year although contingency plans are in place to increase output to around 100,000 tonnes if planning permission is granted for the extension of a new runway at the island’s airport.
Quarry manager Kevin Brookes said: ‘Roadstone is a vital commodity in an island community such as this as it is prohibitively expensive to import it from the UK mainland. We see the dolorite at Poortown as a national asset to be controlled and safeguarded.’
The blasted dolerite is loaded into a Lokotrack LT 105 track-mounted mobile crushing plant and the resulting product is fed directly into a Lokotrack LT 200 HP cone crusher, which in turn discharges into a Metso ST 352 screen to produce a 28mm product. This is fed directly into a second LT 200 HP cone crusher before being screened over a series of three Metso double-deck units – one ST252 and two ST348 machines – to produce a range of single-sized aggregates.
Production rates at the quarry are dictated primarily by local demand with the aim of serving the island’s needs first and private companies second. The most popular grades are a 6mm product, used largely for footpaths, and a 10mm product used as a surface coating on the island’s roads. The quarry also produces 14mm and 20mm grades for road use, and there is currently a significant order for railway ballast being processed by the Metso Minerals plant.
‘The material here is very hard but it is also naturally flaky. It is important that we get the right product shape with the minimum possible waste,’ commented Mr Brookes. ‘The Metso cones are the ideal crushers for this; the shape of the finished product from the HP machines is absolutely brilliant.’