STUDY OF BIOLEACHING OF LITIUM (LI), STRONTIUM (SR), AND RARE EARTH ELEMENTS (REE) FROM SIDOARJO MUD USING MIXED CULTURE OF BACTERIA ALICYCLOBACILLUS FERROOXYDANS STRAINS SKC/SAA-2 AND SERRATIA RUBIDAEA STRAINS SKC-11

• Main Author: Ahyar
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/69374
• Institution: Institut Teknologi Bandung

Sidoarjo Mud (Lusi) is an overflow of hot mud near an oil drilling located in the Sidoarjo area. Based on the Geological from Ministry of Energy and Mineral Resources (ESDM), the valuable minerals found in Lusi include lithium (Li), strontium (Sr), and rare earth elements (REE) which are included in Critical Raw Materials (CRMs). Until now, Lusi's utilization is still focused on brick and cement materials and there has not been much research related to the extraction of these precious metals. In this study, bioleaching experiments of Li, Sr, and REE were carried out using a mixed culture of bacteria. As well as studying several variables that affect the percent extraction. The research activity began with the preparation of Lusi's samples including drying, homogenization, and sampling. The samples were also characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), and inductively coupled plasma-mass spectrometer (ICP-MS), as well as characterization of the particle size analyzer (PSA). Next, the adaptation experiment and the selection of bacteria were carried out. Abiotic experiments (without bacteria) were also carried out to determine the effect of leaching without the use of bacteria. After that, the leaching core experiment was carried out for seven days with various bacterial ratios, percent solid (2%, 5%, 8%), sulfur (0 g/L, 5.5 g/L, 10 g/L), and ferrous sulfate (0 g/L, 24.82 g/L, 44.68 g/L). Leaching was carried out at room temperature (25oC) using a rotary shaker with a speed of 180 rpm. The leaching residue was also analyzed using fourier-transform infrared spectroscopy FTIR. The experimental results showed that from the six, two of the best bacteria suitable for leaching Lusi were Alicyclobacillus ferrooxydans strain SKC/SAA-2 (Bacteria A) and Serratia rubidaea strain SKC-11 (Bacteria BS-8L). Experiments with 2% solid percent gave the best extraction percent with Li extraction percentage of 98.31%, Sr of 58.94%, and total LTJ of 75.06%. The addition of 5.5 g/L sulfur gave the highest percentage of Li extraction of 85.43% and the largest total LTJ of 61.46%, while the element Sr had no effect on the addition of sulfur, 37.26% Sr was reached at 0 hour. In the ferrous sulfate variation, the addition of 0 g/L ferrous sulfate or without the addition of ferrous sulfate gave the highest percentage of Li extraction of 90.53% and the addition of 44.68 g/L of iron sulfate gave the highest percentage of total extraction of LTJ of 61%. Meanwhile, the Sr element did not give a significant effect, the extraction percent of 35% was achieved at 0 hour.