LEACHING OF PONGKOR GOLD ORE IN AMMONIUM THIOSULFATE SOLUTION AND RECOVERY OF GOLD WITH ACTIVATED CARBON AND ANION EXCHANGER RESINS

• Main Author: PRAWIRA MINWAL (NIM : 12506032) , WAHYUDIN
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/24668
• Institution: Institut Teknologi Bandung

Gold extraction process is most commonly conducted thorough cyanidation leaching. Despite its excellences, the cyanidation leaching has a negative effect on the <br /> <br /> <br /> <br /> environment due to its poisonous nature and innefective to be used for refractory ore type. Investigations have been made in order to find alternative reagents to replace cyanide, in which thiosulfate solution is one of the most attractive reagents. In this research work, the effectiveness of thiosulfate for the extraction of gold from gold ore received from UBPE Pongkor, PT. Antam, Tbk. is studied. Recoveries of gold from pregnant leach solution were carried out by using activated carbon and three types of anion exchanger resins from Lewatit. <br /> <br /> <br /> <br /> Series of leaching experimental works were undertaken in a five-neck reactor by varying concentrations of ammonium thiosulfate, temperature and duration of <br /> <br /> <br /> <br /> leaching. Dissolved gold concentrations were determined by AAS (Atomic Absorption spectrophotometer) analysis and the percentages of gold extraction were calculated. Kinetics of gold leaching has been approached with a Spherical Shrinking Sphere model. Recovery of gold from leach solution was performed by Carbon/Resin In Solution Method in which activated carbon and resins were agitated in the leach solution. The resins used are Lewatit Monoplus MP800 resin (strong base resin), <br /> <br /> <br /> <br /> Guanidine resin (weakly basic resin), Lewatit AF 5 resin (resin-based carbon matrix) and the activated carbon is that usually used in Pongkor. Adsorption tests were done <br /> <br /> <br /> <br /> by varying the solution pH in the range of 7-9 for 25 hours.