Sandvik screening plant for Ethiebeaton Quarry
Situated near the northern shore of the river Tay on the outskirts of the city of Dundee, Ennstone Thistle’s Ethiebeaton Quarry was recently equipped with a new asphalt facility and crushing plant. The next stage involved the design, supply and installation of a new static screening plant.
The design criteria required a screening plant capable of receiving 300 tons/h of basalt from the crushing plant and producing seven finished products (+28mm, 28mm, 20mm, 14mm, 10mm, 6mm and dust), and ultimately a 20–5mm concrete aggregate.
The first triple-deck screen had to effect a four-way split, with the +28mm, 28mm and 20mm either going to stock as final products or being recrushed before rejoining feed to the screening plant. The –20mm underflow from the first screen was to be carried forward to a double-deck screen configured to split the material at 6mm and 4mm. The –20mm +6mm rejected by the top deck of this screen was to be sent forward to a final double-deck screen for separation into 20mm, 14mm and 10mm final products.
Sandvik were awarded the screening plant contract in August 2004 and were required to ensure delivery before the end of October 2004, which would allow for installation to be completed before the end of February 2005.
With a maximum feed rate of 420 tons/h to screen number one, the decision was taken to supply a Sandvik Roxon 2.4m x 7.0m triple-deck elliptical-motion screen inclined at 5º. Sandvik Stepdeck modular polyurethane screen media was chosen to give the required separations of 28mm, 20mm and 14mm, with the special trapezoidal-shaped polyurethane modules preventing material tracking down the blank areas and allowing maximum use of the screening area. The unit’s twin-mechanism, top-mounted modular drive allows for easy access between the decks for media inspection and panel changes when required.
For screen number two, a Sandvik Roxon 2.7m x 7.0m double-deck elliptical-motion screen, inclined at 7º, was chosen to give the required separations of 6.3mm and 4mm. Sandvik Flexdeck modular screen media is fitted to the top deck with harp wire being used on the bottom deck.
The rejected 20mm, 14mm and 10mm fractions are separated on screen number three, a Sandvik Roxon 2.4m x 6.0m double-deck, circular-motion screen, inclined at 18º and fitted with Sandvik Stepdeck PU modular screen media. All three screens were fitted with dust encapsulation to prevent escape of dust to the atmosphere.
