STUDY OF BIOLEACHING BEHAVIOUR OF ZINC SULPHIDE CONCENTRATE FROM BOGOR USING Pseudoclavibacter sp. and Luteococcus sanguinis BACTERIA

• Main Author: Revalino, Rido
• Format: Final Project
• Language: Indonesia
• Subjects: Metalurgi
• Online Access: https://digilib.itb.ac.id/gdl/view/36729
• Institution: Institut Teknologi Bandung

Zinc (Zn) is one of metal of II-B group in periodic table that is widely used in daily life. Most of zinc are produced from its primary sources, namely from sphalerite mineral (ZnS).One of the methods that is developed to extract zinc from its sulfide mineral concentrate is by bioleaching method. Biohydrometallurgical zinc processing has advantages in comparison to other zinc processing routes, in which it does not produce SO2 gas which is toxic and requires special treatment and offers relatively lower capital cost than that for pressure leaching and atmospheric agitation leaching processes. Therefore, it is necessary to further study zinc extraction method by biohydrometallurgical route as an alternative for zinc extraction method which is cheap and environmentally friendly. In this study, zinc extraction from ZnS concentrate received from PT BCMG Tani Berkah, Bogor, West Java was studied by bioleaching by using Pseudoclavibacter sp. and Luteococcus sanguinis at room temperature. Series of bioleaching experiments using Pseudoclavibacter sp. bacterial and Luteococcus sanguinis bacteria have been carried out at atmospheric pressure to study the effect of pulp density (w/v), percentage of inoculum of bacteria (v/v), type of bacteria, bacterial growth medium, and NaCl concentration on zinc extraction. Several analyses were carried out on initial sample of concentrate which includes X-Ray Difraction (XRD), X-Ray Fluorescence (XRF), and Scanning Electron Microscopy/Energy Dispersive X-Ray Spectroscopy (SEM/EDS). Bioleaching process took place at room temperature using shaker at 180 rpm. The bioleaching experiments were carried out in 3, 5 and 6 days, according to the result from the preliminary experiments. The concentrations of dissolved zinc was determined periodically by using Atomic Absorption Spectrophotometry (AAS) and the extraction percentage of zinc was determined. SEM-EDS analysis was also conducted on the residue of the leaching test which resulted in highest extraction of zinc. The result of Bogor sphalerite concentrate bioleaching using Pseudoclavibacter sp. showed that the highest extraction of zinc of 56.6% was obtained from the leaching experiment after 5 days under condition of 10% (w/v) pulp density and 20% (v/v) inoculum of bacteria. At this condition, the highest selectivity of zinc leaching to lead of 0.98 (0-1 scale) was also obtained. Meanwhile the bioleaching experiment with Luteococcus sanguinis bacteria resulted in the highest zinc extraction of 38.76 % after 6 days under condition of 2% (w/v) pulp density, 20 % (v/v) inoculum of bacteria and 2 g/l of NaCl concentration.