#TITLE_ALTERNATIVE#

• Main Author: FIRDAUS (NIM: 12514051), RAHMAT
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/30142
• Institution: Institut Teknologi Bandung

Nowadays, zinc is one of the metals mostly used in daily life due to its properties such as high corrosion preventive characteristics and ease to bond with other metals. Zinc itself is mostly contained in sphalerite minerals. Based on the data, the demand of zinc metal is rising up to 14,3 million tons in 2017, yet the production for zinc is only 12,7 million tons. Generally, zinc extraction process is undertaken through hydrometallurgy method known as roasting-leaching-electrowinning (RLE). However, this process exhibits harmful pollution gas and needs many leaching reagents. Thus, RLE is not an economical, environmental friendly method. As an alternative process, zinc extraction is conducted by using bacteria, called bioleaching. Hence, the present study dealt with about the effectiveness of bioleaching process of low grade Pb-Zn complex ore from District Bogor, West Java. <br /> <br /> Series of experimental were carried out to study the effect of chloride ions, dissolved FeSO4.7H2O, pulp density, the ratio of pyrite and sulfur to ore, and initial pH adjustment on zinc extraction process using Alicyclobacillus ferrooxydans strain SKC/SAA-2 and Citrobacter youngae strain SKC-5. The complex ore sample had a size of -200 mesh (75 &#956;m). The sample was characterized using X-ray diffraction (XRD) and X-ray fluorosence (XRF). Leaching was conducted under aerobic condition on rotary shaker with a speed of 180 rpm. Every day, 5 ml of the pregnant leach solution was periodically sampled to analyze zinc dissolved in solution using atomic absorption spectrophotometry (AAS). <br /> <br /> Experimental result showed that Alicyclobacillus ferrooxydans strain SKC/SAA-2 and Citrobacter youngae strain SKC-5 were able to leach zinc from low grade Pb-Zn complex ore with the highest extraction level of 91,42% and 88,63%, respectively, at initial pH 3, 2% (w/v) pulp density, and 10% (v/v) inoculum in modified Fe-broth with addition of 1% (w/v) pyrite, 0,25% (w/v) sulfur elemental, and 29,25 g/l NaCl. The result also showed that chloride ions, FeSO4.7H2O addition, low pulp density, the low ratio of pyrite and sulfur to ore, and initial pH adjustment could increase the extraction level of zinc.