A case study in uniform conditioning of local recoverable reserves estimation for Jelšava magnesite deposit - level 220

Abstract

A practical case study for estimation of magnesite grade in Jelšava deposit in Slovakia is presented. The studied part of the deposit is a new level 220, vertically extended to the level 323, presently being exploited. Based on exploratory data analysis, the distributions of studied variables were modelled using Gaussian anamorphosis and transformed into normal distribution. The structural analysis and consequential variography was made for transformed variables in 3D space, resulted in a complex structural model of the spatial variability. Following the structural model, the average grades were simulated for the projected selective mining units (SMU) 16x16x6 m (panels). For recoverable reserves estimation purposes, the raw variables were transformed into Gaussian space for SMU volume as well as discretizating blocks 4x4x6 m inside each SMU. The results of the previous simulations and the change of support models were used for recoverable reserves estimation by uniform conditioning for series of different cut-offs.