Mining of the ″Faults″ Ore at the Largentiere Mine.

In 1970, after six years of mining at the lead-zinc deposit of Largentiere by the room-and-pillar method, the reserves of high-grade beds in the upper horizon and of large and low-grade beds in the lower horizon appeared to be exhausted. The following measures were taken: production of the low-grade ore was stepped up, combined with an improvement in productivity, and the drop in the assay values was restricted by maximum recovery of high-grade ore. To implement the first measure, the mechanization of the drilling operations was intensified. The second measure called for a large expansion in prospecting, as well as in the mining of the faults. Thanks to these improvements, the decline of the Largentiere mine was successfully deferred.