The progressive Liam Lynch operates it’s limestone quarry in Croom, Co. Limerick were they have been producing aggregates (20mm, 14mm, 10mm and a 6mm to 0mm dust) and 804, a crushed 2” down material.
The quarry dust (6mm to 0mm) produced was a by-product in the quarry and stockpiled as waste. This is common place throughout quarries in the UK and Ireland as traditional washing and dry screening systems are unable to make a commercial product from this dust.
The new CDE system washes this 6mm to 0mm quarry dust and produces concrete sand by removing the 75 micron material. This concrete sand is then used by Liam Lynch in their own concrete batching plant where they produce Ready Mixed Concrete.
Before the new CDE system was installed it was necessary to buy all of the sand required for the concrete production. This has been reduced to only 20%, the other 80% of their mix being made up by the concrete sand produced from their once waste quarry dust.
The CDE plant is also used to wash some dirty overburden that the traditional dry systems could not process. This is washed into clean 20mm, 10mm and sand for the concrete mix. The washed oversize is then put back through the crushing plant and re-processed.