BIOFLOTATION OF GALENA-SFALERITE COMPLEX ORE USING BACTERIA PRODUCING BIOSURFACTAN AS A BIOREAGENT

• Main Author: Hartina, Sitti
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/56392
• Institution: Institut Teknologi Bandung

The increasing demand for base metals such as lead (Pb) and zinc (Zn) has led to increased exploitation of the minerals galena (PbS) and low grade sphalerite (ZnS). The presence of PbS and ZnS in nature is often found in association with pyrite (FeS) impurities, in addition to being associated with common impurities, namely silica (SiO2). It takes a concentration process to selectively separate valuable minerals from other impurity minerals. This is what underlies the development of alternative technologies in the separation of PbS and ZnS from FeS2. The bioflotation process is a concentration process used on low grade ores by using bioreagents instead of chemical reagents. The use of bioreagents in the bioflotation process using a variety of bacterial cells and biosurfactants was carried out to determine the effect of bacterial cells and biosurfactants produced by bacteria on the hydrophobicity of mineral surfaces. Bioflotation experiments were carried out with bioflotation process variables including variations of bacterial growth medium, bioreagent, and slurry pH. The best bacteria used in the flotation experiment came from the results of screening 10 bacterias using emulsifying activity (E24) analysis. Experiments on the bioflotation process were carried out using a Denver flotation cell. Analysis of mineral content in the sample of galena-sphalerite complex sulfide ore as well as the results of the bioflotation process were analyzed using XRD (X-Ray Diffraction) and ICP-OES to determine the levels of each metal. In addition, FTIR (Fourier Transform Infra Red) and SEM (Scanning Electron Microscopy) analyzes were also performed to determine the interaction of bacteria with the galena-sphalerite sulfide complex. The results of bacterial screening using E24 analysis of 10 species of bacteria obtained 1 best bacteria are bacteria Paenibacillus pasadenensis (Pp) with E24 value reached 44.62% at hour 24. The results of experiments using bacteria Pp bioflotasi provide recovery of Pb and Zn values highest, respectively Pb recovery of 60.43% with grade 9.9% and Zn recovery of 50.79% with grade 4.47%. Those results were obtained under conditions in the growing medium conditions of LBbroth + S, bioreagen B (biosurfactant) and pH of slurry 5, The lowest Fe recovery value reached 3.78% with a grade 4.02% in LB-broth growing medium conditions, bioreagent B and pH of slurry 5. For the highest selectivity index (SI) of Pb to Fe and Zn to Fe with SI values of 2.6 and 2.4 respectively under experimental conditions with LB-broth growing medium, BB bioreagent (bacteria and biosurfactant) and carried out at pH of slurry 3. The bioflotation process showed Pb and Zn content increased, while Fe content decreased in each concentrate of the experiment. This indicates that it is possible for P.p bacteria to be used as a bioreagents in the flotation process.