VALUATION AND PRODUCTION OPTIMIZATION OF A METAL MINE

A zinc mine, stoped by the room and pillar method, has been evaluated by geostatistical techniques. The computation of the kriging estimator of the average grade of the stoped rooms and the correspondent estimation variance has been carried out in the already exploited mine section. In the other mine section, to be exploited, smaller size blocks have been estimated using the kriging procedure in order to gain some information to define the size and position of the new stoping rooms. The shape of the stoping room top-wall has been defined optimizing the recovered metal tonnage for a fixed cut-off grade. The convex analysis has been used to determine the optimal ″total recovered metal tonnage vs. total recovered ore tonnage″ curve, on the basis of the estimates, by the kriging of the stoping rooms subdivided into a large number of small slices.