Finedoor has recently completed an installation of an ORTNER Sand Classification Machine for a major Scottish Quarrying Company.

Approached to supply an Ortner 3000 sand classification machine to process 350,000 tonnes of -6mm granite (with 12% passing -63 micron) waste material, which over the years had been produced and stockpiled. Finedoor were challenged with the goal of reducing the -63 micron down to 5%.

The ORTNER which is a well proven concept for dewatering, removing fines, classifying and rinsing sand and other materials up to 60mm has the performance capabilities and advantages unmatched by other machinery. It is currently used by the majority of the major aggregate producers in the USA.

Production process:

Finedoor supplied an ORTNER 3000 which was capable of processing 80-100tph with a water requirement of 130-170gpm depending on the gradation of the material fed to the machine. Mounted on a skid sub frame assembly the ORTNER 3000 features a variable speed drive, 2 vibrating mechanisms and a height adjustment mechanism. Further features include a rubber lined mounted feed box, centralized greasing point, overflow collection flume and a centre discharge with replaceable wear ring.

The operation and principle are simple. Material is fed to a slowly revolving pan on an incline and vibrated at high speed. The high speed vibration quickly separating the various sizes of material with the fines and water rising to the top and flowing over the weir to the discharge.

With the coarser particles sinking to the bottom the rotating pan carries the settled particles up the machine and out of the water, where a stationary plough diverts the dewatered material to a centre discharge chute. The driving and vibrating mechanism is mounted under the pan, preventing any contamination with the water and processed material, thus increasing the life of the components. It is possible to vary the angle, speed, and vibrations of the pan. Washed material is then fed onto a 7.2 metre x 650mm wide inclined transfer trough belt conveyor which, in turn delivers to a radial stockpiler.

Currently processing the waste material at 80tph with an end result of -63 micron washed down to 3% the installation has been extremely successful and has subsequently provided the capability to feed an on-site coating plant with sand which previously had been supplied from a sister company approximately 10 miles distant.

This has proved to be highly beneficial with the obvious elimination of transport costs and subsequent environmental benefits from the reduction of their carbon footprint.

Within the project, Finedoor manufactured and supplied the ORTNER 3000 and the installation was then commissioned on site by Finedoor engineers.

The ORTNER is manufactured by Finedoor in the UK under license from AEI, USA Based in Morley, Leeds Finedoor are recognised as a manufacturer of high quality screens for both aggregate and asphalt applications Finedoor have supplied all major quarry groups in Ireland, UK and the Middle East. With currently over 400 ORTNER machines currently operating in North and South America, Finedoor have recently introduced this mature technology into the EU.