Methods of mining with cemented backfilling in the uranium mine of Lodeve

The mining division of the Herault works at Mas Lavayre an uraniferous deposit in the Eastern part of the Permian basin of Lodeve. The mineralizations, contained in sandstone-carbonate beds, occur in three principal forms: - massive ore zones of 10 to 60 m vertical extent; - beds with a thickness varying from 1 to 8 m; - fissure veins on faults. The mining operations proceed in descending order under cemented backfilling. The backfilling material, made up differently depending on the method, is composed on the surface in a central station for cement grout which is forwarded below ground through cased boreholes and then placed by scooptrams and ''concrete pusher'' appliances which permit a solide packing in the crown section. The backfilling productivity is of the order of 200-250 cu.m per shift. The deposit of Mas Lavayre is thus mined by a set of mechanized methods which utilize cemented backfilling material as a function of the geometry of the mineralizations