STUDY OF BIOLEACHING BEHAVIOUR OF MAGNESIUM FROM FeNi SMELTING SLAG USING BACTERIUM Alicyclobacillus ferrooxydans

• Main Author: MUHAMMAD CHAFID , ADIB
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/20732
• Institution: Institut Teknologi Bandung

Slag is a by-product of smelting process in the form of complex or simple compounds which usually include oxides, sulfides, and halides. To date, smelting slag, especially ferronickel (FeNi) smelting slag of PT Antam (Persero) Tbk. UBPN Sultra, has not been optimally utilized. This causes problems for the storage of slag. Moreover, slags are classified as hazardous and toxic wastes so that its further handling is needed. One of the compositions found in slag is magnesium (Mg). The magnesium content in FeNi smelting slag is about 16.9%. With this content, magnesium becomes potential for extraction from slag. Metal extraction through the use of microorganisms (termed bioleaching) at present is growing rapidly. Therefore, this study was conducted to study the bioleaching behaviour of magnesium from the FeNi smelting slag of PT Antam (Persero) Tbk. UBPN Sultra using the help of microorganisms, namely the bacterium Alicyclobacillus ferrooxydans. <br /> <br /> <br /> <br /> <br /> <br /> The experiments were firstly started with a slag sample preparation, which included grinding, sieving, and sampling. Preparation of Fe-broth medium and culture of the bacterium Alicyclobacillus ferrooxydans using Fe-broth medium were performed for 3 days of incubation. The bioleaching experiments using modified Fe-broth media in several experimental variations (i.e., pulp density, molasses concentration, introduction time of slag and pyrite) were carried out to study their effects on magnesium extraction, dissolved iron, and Eh-pH changes occurring during leaching. The leaching was performed using a gyratory shaker at 180 rpm and . <br /> <br /> <br /> <br /> <br /> <br /> The leaching results showed that the highest extraction of magnesium was 67.67%, which was obtained from leaching experiments for 4 days at 5% pulp density, 1 gr/L molasses, introduction time of slag and pyrite after 2-day leaching inculated with bacterial suspension of 10% (v/v). Magnesium leaching from FeNi smelting slag of PT Antam (Persero) Tbk. UBPN Sultra using the bacterium Alicyclobacillus ferrooxydans had a slightly selectivity to iron with the selectivity index of below 0.6. <br /> <br />