Advanced Rock Drilling Technologies Using High Laser Power

Drilling through hard rock formations causes high mechanical wear and most often environmental disturbance. For the realization of an Advanced Adiabatic Compressed Air Energy Storage (AA-CAES) power plant a new and efficient method for tunneling utilising laser technology to support mechanical ablation of rock formations will be developed. Laser irradiation of inhomogeneous rock surfaces causes irregular thermal expansion leading to the formation of cracks and splintering as well as melting and slag-formation. This study focuses on the interaction of laser irradiation with calcite, porphyrite and siderite rock formations. A high power disc laser system at 1030nm wavelength is used to investigate the specific energy necessary to remove a unit volume depending on interaction times and applied power. Specific energies have been measured and an increase of fragility and brittleness of the rock surface has been observed.