DRILL-HOLE SPACING OPTIMIZATION USING GEOSTATISTICAL METHOD FOR THE BASIC GUIDELINE OF RESOURCES CLASSIFICATION OF TIN AND ITS ASSOCIATED MINERALS CONTAINING REES FOR INLAND ALUVIAL DEPOSITS IN BANGKA ISLAND

• Main Author: Kosher Sianturi, Raymond
• Format: Theses
• Language: Indonesia
• Subjects: Pertambangan dan operasi berkaitan
• Online Access: https://digilib.itb.ac.id/gdl/view/51587
• Institution: Institut Teknologi Bandung

Bangka Island is a rich area for granite rocks bearing tin mineralization. Besides bearing rich tin mineralization, granite is also bearing ilmenite, rutile, anatase, zircon, monazite, and xenotime minerals, which are associated minerals found in alluvial tin deposits and called as “tin associated minerals”. Monazite and xenotime are minerals that containing the Rare Earth Elements (REEs). Drill-hole spacing optimization for tin and its associated minerals containing REEs is required so that these spaces could represent the spatial continuity of both commodities. The basic guidelines for classifying the resources of tin associated minerals that containing REEs must also be developed so that they could be applied by industry. The method used in this study is geostatistics using Global Estimation Variance (GEV) to calculate the relative error. This study showed that tin is statistically and spatially more homogeneous than its associated minerals. The tin associated minerals that containing REEs i.e. monazite is statistically and spatially more varied than the tin and other associated minerals. The optimum drill-hole spacing representing Sn (tin) and its associated minerals are 20 – 25 m for Measured, 30 – 40 m for Indicated, and 40 – 50 m for Inferred resources. The current guideline for classifying the tin resources used by PT Timah Tbk. which considering the range of variogram (a) has been appropriate yet. However, that guideline was not appropriate yet to represent the spatial continuity of tin associated minerals because it needs closer spacing. The more appropriate guideline for resources classification of tin associated minerals that containing REEs was ? 1/2a for Measured, 1/2a – 2/3a for Indicated, and > 2/3a for Inferred resources.