First publishedin Aggregates Business Europe
Europe's largest mobile crushers are helping to process greywacke in County Tipperary, Ireland
County Tipperary in Ireland may not seem a likely place for records to be set but it currently holds the title for the largest mobile crushing and screening plant in Europe. Latteragh Quarry took delivery of what is believed to be the largest and most powerful track-mounted mobile crushing and screening plant in Europe last year.
The manufacturer behind these record breaking mobile units, which have a feed capacity of more than 500tonnes per house, is Germany's Kleemann
. Seven different final aggregate fractions are produced in a three-stage crushing operation, five of them complying with the quality requirements for asphalt and concrete production.
The decision to go with Kleemann plants has been a result of the good experience the operating company - Kelly's of Fantane - had with previous plants. According to the company, the other Kleemann machines proved their strenghs and power in thousands of operating hours under the roughest conditions. Furthermore, the good level of service and support provided by local Kleemann dealer McHale in the past made the decision even easier.
The process of determining the right plant configuration took several months and the process involved close collaboration between Kleemann, Mchale and the Kelly's of Fantane plant manager Martin Flynn.
The feed material is a hard greywacke with a density of up to 2.6tonnes/m³. It is quarried by blasting prior to being delivered into the Mobicat MC 140 Z jaw crusher by means of an 80tonne excavator. Contamination is removed by the large double-deck pre-screen. After primary crushing the greywacke has a grain size ranging 0-250mm. Discharge conveyors then transport the material to the first of two mobile secondary Mobicone MCO 13 S crushers, where the 0-20mm grain sizes are screened and stockpiled prior to the secondary crushing operation.
The remaining material with grain sizes of 20mm or more produced by the first KH 400 cone crusher at a closed side setting of 30mm is then processed to chipping size in the second Mobicone 13 S. Aggregates with a 14-20 mm grain size are stockpiled by this machine.
The fourth plant of the process chain is a Mobiscreen MS 20 D triple-deck screening unit which is used to screen the remaining 0-14mm material to four final aggregate fractions of 0-5mm, 5-8 mm, 8-12 mm, and 12-14 mm.
This screening plant features a banana type triple deck screening unit and 2050x6000mm sized screen decks to make sure the maximum screening output will be achieved. Even with the critical grain size 0-5mm. it delivers an output of over 100tonnes per hour.
The final aggregate fractions produced in Latteragh Quarry are used in the nearby asphalt plant, and also in a concrete plant. The pre-screen material resulting from the processing operation is sold into the local construction market.
According to Kleemann, this plant combination shows how the advantages of tracked mobile plants can be used in such complex and high-output applications, which had not been considered possible a few years ago.