Study of Bioleaching Behavior of Copper Ore from Pulau Wetar Using Isolate of Bacillus pumilus SKC-2 and Citrobacter youngae SKC-5

• Main Author: (NIM : 12514001), ALDO
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/25317
• Institution: Institut Teknologi Bandung

Copper is one kind of metals that mostly used in many industrial sectors. This metal has a good thermal and electric conductivity, easy to forge, and good durability. Naturally, copper formed in the crust in many kind of precipitates such sulfide, carbonate, silicate, and as a pure metal. Copper extraction by applying smelting-converting and electro-refining were dominated around 1800. Implementation of physiochemical extraction produced toxic gas such as sulfur dioxide. Nowadays, 25% of copper production extracted through hydrometallurgical route. Bioleaching believed as one of the economic methods in applying hydrometallurgy. In this study, copper from complex of sulfide ore that was collected from Pulau Wetar extracted using Bacillus pumilus SKC-2 dan Citrobacter youngae SKC-5. <br /> <br /> This research was started by preparing the complex of sulfide ore that was divided in 3 steps; commination, sieving, and sample collection. Then, the ore was characterized using X-Ray Diffraction (XRD) dan X-Ray Fluorescence (XRF). Total bacteria was determined using spectrophotometry by measuring optical density from growth medium and leaching was done for 5 days, agitated 180 rpm, and incubated at 25oC. To determine the effect of percentage of extraction, dissolved iron concentration, and Eh-pH change during the process, 3 variables were set; solid percentage, inoculum concentration, and fraction of ore size. <br /> <br /> Ore sample was dominated by silicate (SiO2), pyrite (FeS2), and cuprite (CuO2) and the concentration of copper observed around 3.5% based on ore sample characterization. Total bacteria count using Fe Broth medium showed that the stationary phase of Bacillus pumilus SKC-2 and Citrobacter youngae SKC-5 reached at 24 and 48 hours of incubation. The highest copper extraction 77,61% was obtained at treatment of using 20% v/v inoculum of Citrobacter youngae SKC-5, 10% w/v of solid concentration, and ore size less than 75&#956;m. Based on Eh and pH value, the solution was dominated by copper ion.