Costiolo quarry in Brembana Valley (Bergamo--Italy): underground exploitation and comminution techniques directed towards lime production. Project evolution since Eighties to today

摘要

Costiolo limestone quarry is situated in Brembana Valley, in the municipal district of Ubiale Clanezzo (Bergamo); fully operational in open pit since Thirthies of the last century, at the moment it is operated underground by Unicalce SpA, after the drifting in Nineties. The site, a real example of classic mining activity apart from the juridical definition of "quarry", already has been the subject of numerous papers; only in order to deepen our work typology, we briefly remind the project peculiarities (Fig. 1):--Ore: "Conchodon dolomite", >98 percent CaCO_3, thickness about 180 rn, subvertical stratification--Quarrying method: sublevel sloping; 3 sublevels + 1 base level--Dimensions: each room is high 115-120 m, large 30 m and long 180-190 m--Diaphragms: afterwards named "pillars", they have 40 m of thickness. This statement will explain the changes (about mining techniques, explosives, geometries, crushing system, etc..) brought during the exploitation of Room 1 and the shift from this one to the second.