Determination of Initial Lag and Maximum Lag Distance of Semivariogram on Reserves Calculation of Gold Vein

Abstract

The reserves calculation is one of the early stages before the mining operation, which begins with the
samples prediction. Ordinary kriging is a part of the kriging method that works with semivariogram
parameters. The calculation of these parameters based on several things, including the
determination of the lag distance and the fitting model. This paper is based on the determination of the
maximum lag distance of 500 and 800 where the lag distance for both, respectively 15, 25 and 35 with
WLS and OLS fitting models. The six combinations can be concluded that increasing of maximum
lag distance adds to a large of sill and extend the range. OK prediction shows that the largest gold
grade mean (5.032) occurs in the kriging using WLS fitting models, in which the maximum lag distance
semivariogram is 500 and the distance of each lag is 35.