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Gallagher Aggregates take delivery of the 900th Bivitec screen and resolve their screening problems Gallagher Aggregates currently operate Hermitage Quarry, near Maidstone which is the largest Kent Ragstone quarry. The deposit comprises an inter-bedded 50 - 50 mix of Ragstone and Hassock which is a relatively soft sandy material with a high, but variable, silt content. Within the current production cycle this is separated from the ragstone by a large heavy-duty trommel screen which removes the -75mm material containing the hassock.

Previously conveyed to a mobile screen to remove the -20mm material, Gallagher's found that if the screen was fitted with smaller mesh it would block because the material was so sticky, especially when wet.

Whilst +20mm material was then conveyed to the washing plant to produce clean single size aggregates it was quite obvious that a considerable quantity of good quality stone was lost in the -20mm material with the further disadvantage that this material occupied valuable space on the quarry floor. It became obvious that if Gallagher's could screen at much smaller sizes they could recover this valuable stone and process it through the washing plant.

After initial consultation with DUO a sample of their material was sent to the testing laboratory of Binder in Austria for trials using their Bivitec screen. Gallagher's attended the trials and were very impressed by the capability of the screening system to size their difficult material at very small apertures in comparison to traditional screens.

Follow the successful trials DUO engineers evaluated the current operation and measure the site with the view to installing a large Bivitec screen in-line with the existing plant. Having presented detailed layout drawings to Gallagher's illustrating how the new Bivitec screening system would fit in conjunction with their current operation the final price was agreed and the screen was ordered. The screen supplied is 8m long by 2.4m wide with 25mm aperture fingers on the top deck, and 6mm aperture polyurethane mats on the bottom deck, and is capable of taking a feed rate of 500tph.

Martin Hobbs the Managing Director of Gallagher Aggregates commented on the project - "We are impressed by the approach of DUO. We had a problem and after initial discussion they provided the solution. Their approach was planned at each stage and we are very pleased with the quality and performance of the final product."