Ordinary kriging comparison and inverse distance weighting for quality assessment of Vietnam cement limestone deposits

Abstract

Limestone deposits are primary raw material for cement manufacturing plants. However, mining engineers and geologists faces challenges in determining an appropriate, accurate and cost effective estimation method. The aim of this research is to evaluate and compare the applicability of two geostatistical methods, Ordinary Kriging (OrK) and Inverse Distance Weighting (IDW), for estimating quality of the Ta Thiet limestone, a lithological structure deposit at Binh Phuoc province (Vietnam). For this purpose, data collected from 194 exploratory boreholes were analyzed by statistics to calculate and generate the anisotropic ellipsoids and the variograms of the constituents in the limestone deposit. The correlation analyses of the estimation result showed that although OrK is a good estimation method, however it is complex and time-consuming, whereas IDW showed better result. Therefore, IDW is a cost effective method for estimating quality of the limestone deposit. Based on the assumption that things that are close to one another has more influence than those that are farther apart, ID method predicts a value of an unmeasured location using the measured values of the locations surrounding it. Weights are assigned to data points depending on the unmeasured point’s distance to the measured location. In this study, the ID method was applied by using results from variography and anisotropic ellipsoid. Preparation of raw mix is beneficial for a number of reasons: it can improve the processing plant efficiency, and it minimizes the need for selective mining, hence reducing mining costs and increasing production.