Tailings storage at Lisheen Mine, Ireland

The Lisheen Mine, owned jointly by Anglo American and Iverna West, is located near Moyne, County Tipperary, Ireland. The mine produces lead and zinc concentrates derived from sulphide rich ore hosted in dolomitised limestone. Acid generating tailings from processing of the ore are deposited using the sub-aqueous technique in a fully composite lined tailings management facility (TMF), which is located on a peat bog. The TMF is the largest fully lined tailings storage facility in Europe and deposition of tailings is from a mechanised floating head capable of spreading the tailings evenly over the basin. cility has been constructed in two stages. Stage 1 of the TMF was constructed during 1998 to a maximum height of 12 m (elevation 130 m AOD) which included the removal of peat from the dam wall footprint, the installation of a composite LLDPE lining system, installation of rail tracks on the northern and southern embankment crests for the tailings distribution system and instrumentation. A micro-gravity survey was conducted to identify any paleokarstic structures within the underlying dolomitised limestone. Stage 2 works were constructed during 2002/2003, which included raising the dam walls by 4.5 m to a crest elevation of 134.5 m AOD, the extension of the composite lining, the installation of a central chimney drain and additional instrumentation. aper presents an overview of the methodology employed during the design of the facility as well as construction issues and the findings of the micro-gravity survey.