Abstract: In view that the traditional test formula of variogram function is sensitive to specificity values and the deflection from distribution assumption, robust statistics method and simplex fitting arithmetic for the test variogram function under three dimension condition are introduced. Through the analysis of the variogram function of the composite sample and mineraization space, the anisotropy characteristic of model data is determined and the corresponding data searching and estimation method for lithology are used. Based on this, the grade model of the iron element of a mine is established by 3D block modeling and robust Kriging method. The comparison of the estimation results and the real deposit condition has proved the accuracy of the model.

Key words: 3D variogram function, Robust statistics, Kriging method, Grad modeling