County Tyrone-based CDE Ireland Ltd, specialists in the design and manufacture of tailor-made processing equipment for the sand and aggregates industries, have recently installed a complete new processing system for Liam Lynch (Quarries) Ltd’s limestone quarry in Croom, Co. Limerick.The system includes Ireland’s first overhead-beam GHT filter press, which recycles the maximum amount of water possible and reduces water requirements at the site to only a small amount of top-up.
The quarry itself produces 20mm, 14mm and 10mm single-size aggregates, an 804 (crushed –2in material), and a 6–0mm dust by-product, which, in common with many quarries in the UK and Ireland, was previously being stockpiled as waste, as traditional washing and dry screening systems were unable to make a commercial product from the material.
The new CDE system, however, washes the 6–0mm dust to produce a concrete sand by removing the –75 micron material.This sand is used by Liam Lynch in their own readymixed concrete batching plant. Before the new system was installed, it had been necessary to buy in all of the sand required for concrete production. Now only 20% of the concrete sand needed is bought, with the other 80% being produced from the quarry’s waste dust.
The CDE plant is also used to wash quantities of dirty overburden that the site’s traditional dry screening systems could not process.This is washed to produce clean 20mm, 10mm and sand grades for concrete mixes, while any washed oversize is recirculated through the site’s crushing plant.