RESERVE ESTIMATION OF LATERITIC NICKEL BY 3 (THREE) DIMENSION ORDINARY BLOCK KRIGING METHOD ; CASE STUDY OF LATERITIC NICKEL DEPOSIT IN PULAU GEE, EAST HALMAHERA, NORTH MALUKU

• Main Author: AIRLANGGA (NIM 12104046), ERIK
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/10356
• Institution: Institut Teknologi Bandung

Mineral reserve estimation is the most important in mining evaluation, because the technical consideration which related to mining activity is depend on the total reserve. At this time, there are some spatial reserve estimation method, but the best estimation method related to spatial modeling and calculation of mineral reserve is geostatistic, namely kriging method. It will be used in this research to estimate and calculate of lateritic nickel reserve in Pulau Gee, East Halmahera, North Maluku.<p>The type of the kriging method which applied in this research is 3 (three) dimension ordinary block kriging method. It is considering of data utilization in spatial aspect three dimension. Modeling and calculating of mineral reserve was done based on block model concept, where the reserve is divided into units of block model and the aim is to get more detail of estimate variable. The estimate variable which used in this research for modeling and calculating of lateritic nickel reserve is nickel (Ni) and iron (Fe) grades. The dimension of units block model is 25 25 1 metres, accordance with range of influence of boreholes and spacing of borehole samples assay.<p> Based on the analysis of variogram, spatial characteristic between the data can be known. The analysis resulted value of variogram's range both horizontally and vertically, it is about 35-43 meters in horizontal direction and about 10-15 meters in vertical direction. On several location, that is Blok Utara and Blok Selatan A have variograms with nugget effect which indicated the existence of erratic data.<p>This research resulted lateritic nickel reserve in Pulau Gee and the calculation based on zone of lateritic nickel deposite, i.e. total of ore reserve in limonite zone was 1,291,000.00 ton with contents of metal Ni was 15,843.63 ton and metal Fe was 437,431.14 ton, the total of ore reserve in LSOZ (Low Saprolite Ore Zone) was 2,172,187.50 ton with contents of metal Ni was 34,439.72 ton and metal Fe was 604,833.34 ton, and the total of ore reserve in HSOZ (High Saprolite Ore Zone) was 7,113,750.00 ton with contents of metal Ni was 197,149.76 ton and metal Fe was 1,060,072.13 ton.