Determining the accuracy of mineral resource estimation using spatial statistical analysis – Case study in nickel laterite ore

Mineral resource modeling and estimation has an important role in determining grade-tonnage curves, ore grade distribution, 3D model, mine boundaries and life of mine. The heterogeneity and homogeneity of ore grades affect the accuracy of ore resource estimates. The mismatch of the variogram model causes the grade estimation to be inaccurate. This study aims to determine the accuracy of mineral resource estimation using spatial statistical analysis. The data in this study is the grade of nickel laterite ore. The research methodology starts from data entry to create a database of each drilling data based on sample heterogeneity for the estimation of nickel laterite grade. The resource model construction approximates the actual model to provide an accurate estimate. Geological modeling and estimation of nickel ore grades using interpolation techniques in geostatistical methods. Kriging is an interpolation technique through semi-variogram and uses the concept of spatial correlation between data. Comparative linear regression analysis between the model and composite data at the same block location in the XY-plot and the cumulative probability curve shows the accuracy of the estimation results. Low CV values and informative variogram parameters facilitate the choice of estimation techniques, because all estimation techniques have the same relative accuracy.