BENEFICIATION STUDY OF HIGH SILICA CONTENT BAUXITE FROM TAYAN – WEST KALIMANTAN WITH REVERSE CATIONIC FLOTATION METHOD IN FINE FRACTIONS

• Main Author: Tandela, Rendy
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/49140
• Institution: Institut Teknologi Bandung

Bauxite is a sedimentary rock with high aluminum content and being used as raw material to produce alumina in the world. According to U.S. Geological Survey Report in 2019, Indonesia is as the seventh most abundant country with aluminum deposits in the world with 3.787 billion tonnes of bauxite resource and 1.282 billion tonnes of bauxite reserve. Indonesia’s lateritic bauxite deposit is a result of feldspar ore weathering and this deposit tends to be easily processed with Bayer Process to produce alumina. As Bayer Process requires the minimum feed content of Al2O3 > 51%, SiO2 < 7% and Al2O3-to-SiO2 ratio > 8, Tayan’s bauxite in West Kalimantan can’t be directly fed to the process as it tends to have high silica content. Thus, concentration method is requires to increase the alumina content and reduce its silica content so that it can be fed to the Bayer process. Flotation method is among the concentration method that is being used to beneficiate the bauxite. Series of experiments have been done in cationic reverse flotation to study the profile of collector dosages, pH, feed size fractions variations towards recovery percentage, content change, Al2O3-to-SiO2 ratio in flotation concentrates and tailings. Experiments were carried on bauxite sample from Tayan, West Borneo. Experiments were firstly done with ore characterization on sample with X-Ray Diffraction (XRD) and chemical composition analysis with X-Ray Fluorescence (XRF). Samples were then being grinded to reduce its sizes to -63 +53 µm, -53 +44 µm, -44 +37 µm, dan -37 µm fractions which were then being processed with flotation method in 1375 mL flotation cell while having Dodecylamine as its collector, starch as its depressant, and Dowfroth 1012 as its frother. Concentrates and tailings were then being analysed its content with Atomic Adsorption Spectroscopy (AAS). Based on the research results, Tayan’s bauxite sample contains quartz, gibbsite, and kaolinite minerals with 42.86% of Al2O3 and 26.56% of SiO2. Results show that DDA with 500 gram/tonnes dosage gives the best Al2O3 recovery result of 56.18% with 3.37 Al2O3-to-SiO2 ratio. Best result is also shown with operation pH of 8 with Al2O3 recovery result of 81.89% and 3.11 Al2O3-to-SiO2 ratio. It is also shown that there is correlation between the increase of process effectiveness as the feed size gets finer. The feed size of -37 µm is shown to be the most ideal feed size throughout the process with Al2O3 recovery result of 62.92% and 4.35 Al2O3- to-SiO2 ratio.