CHARACTERISATION OF RARE EARTH ELEMENTS (REE) IN TIN-ASSOCIATED MINERALS IN SOUTH BANGKA AND BADAU AREAS, BANGKA BELITUNG ISLANDS PROVINCE

• Main Author: Fernando Sihite, Rudy
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/51539
• Institution: Institut Teknologi Bandung

The intrution of granite plutons in Bangka Belitung areas is produced the largest tin deposits in Indonesia. Besides being a carrier of tin as cassiterite, granites also produced REE-bearing minerals such as monazite, xenotime, and zircon. This study aims to determine the characteristics of REE-bearing minerals and REE abundance in the study area. To support this research, 51 samples were taken from the South Bangka region on Bangka Island and Badau on Belitung Island. The characteristics and presence of REE-bearing minerals were observed using polarization microscopy and analysis of XRD, SEM, and EPMA. While the abundance of REE is known from the analysis of the inductively coupled plasma-mass sepctrometer (ICP-MS). Based on the observation of grains using microscope, tin-associated minerals is present in large quantities in concentrate samples so it is very easy to find tin-associated in these sample. The tin-associated minerals were observed as ilmenite, monazite, and zircon. In Belitung samples, zircon is easier to find than South Bangka samples while xenotime is hard to find in any study area. This is also confirmed by XRD analysis that the major of tin-associated minerals are monazite, zircon, and ilmenite while xenotime and rutile are more rare to find. Based on SEM analyisis, zircon in Bangka area has more fractures and irreguler shapes that is resulted by complexity of geological activity. In Belitung area, it is common to find zoning in zircon grains which shows a long crystallization process. Quantitatively, REE-bearing mineral in two research area is monazite that contains high ammount of LREE such as Ce, La, and Nd. The abundance of LREE from monazites was also shown from ICP-MS results that LREE is more abundant than HREE. Normalised or compared to UCC, the highest TREE in Bangka Selatan is concentrate sample that is 800 times more abundant than UCC. Where in Belitung, the most abundant of REE is also concenctrate sample that is 350 more abundant than UCC.