Estimation of Laterite Nickel Resources Using Ordinary Kriging Method in The Garuda Block PT Ceria Nugraha Indotama Southeast Sulawesi

Abstract

Assessing nickel resources before mining is crucial. Ordinary kriging, based on spatial relationships, is key in this estimation process. This study aims to quantify nickel resources using ordinary kriging and classify them into limonite and saprolite with a CoG of 1.5%. Employing statistical and geostatistical methods, it ensures reliability. Criteria such as a coefficient of variation below 1.5 and a sill-nugget difference under 50% favor ordinary kriging. The methodology involves univariate statistical analysis, spatial statistics, resource estimation, and classification based on RKSD. In the limonite zone, nickel content exceeds 1.5% CoG, with a variation coefficient of 0.184 and a 38% sill-nugget effect. Strong correlation (0.8085) and low RMSE (0.5537) indicate minimal data errors. In the saprolite zone, nickel content meets the 1.5% CoG, with a variation coefficient of 0.3893 and a 22% sill-nugget effect. The correlation coefficient (0.6581) and RMSE (0.4422) suggest low data errors. Ordinary kriging estimates total resources at 610,668 tons with an average nickel content of 1.60%. This comprehensive approach ensures accurate resource assessment for effective mining planning.