STUDY OF THE PIONEERA L-800 BIOPOLIMER ADDITION AT THE LEACHING PERFORMANCE OF NICKEL LIMONITES ORE FROM SOROWAKO IN SULFURIC ACID SOLUTION

• Main Author: HANIEF FITRIANSYAH, KAUTSAR
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/22771
• Institution: Institut Teknologi Bandung

In a hydrometallurgical plant, there are several parameters generally used to evaluate the performance of the plant, which includes metal extraction and recovery, production capacity, rate of processes and unit consumption of reagents. The extraction percentage of the leaching process is influenced by several factors such as the ore size fraction and grade, concentration of the leaching reagent, temperature, solid percentage and process duration. One of the methods that can be done to increase throughput and recovery simultaneously is by decreasing the viscosity of slurry at a higher solid percentage. The effect of addition of lignin-based biopolymer of Pioneera L-800 on the performance of laterite nickel leaching in sulfuric acid solution at atmospheric pressure was carried out. In the previous studies for the extraction of gold, the Pioneera L-800 biopolymer was reported to decrease the viscosity of slurry and dispersing solid particles in slurry and resulted in the increasing of metal extraction. <br /> <br /> <br /> <br /> <br /> A series of leaching experiments in sulfuric acid solution using Pioneera L-800 biopolymer were done to study its effect on extraction percentage of nickel and leaching kinetics. The leaching experiments were performed under variations of temperature, sulfuric acid concentration, Pioneera L-800 dosage, and solid percentage. The leaching was done for 12 hours and solution sampling was made after 15, 30, 60, 120, 240, 480, and 720 minutes. Measurements of concentrations of nickel, iron, and dissolved magnesium were performed using Atomic Absorption Spectrophotometer (AAS) to determine extraction percentage and the amount of dissolved oxides. Leaching kinetics was studied by using a shrinking core model to determine rate limiting step and activation energy of the leaching process. <br /> <br /> <br /> <br /> <br /> The experimental results show an increase in temperature and acid concentration increasing the percentage of nickel extraction, while the increase of solid percentage tends to lower the percentage of nickel extraction. The use of Pioneera L-800 biopolymer with dosage of 1200 ppm can reduce the viscosity of slurry by 13.6% and increases the percentage of nickel extraction by 10.44% from 84.94% without biopolymer to 93.81% at 6M sulfuric acid concentration and 20% solids percentage. The increase in nickel extraction followed by co-extraction of iron, in which the highest co-dissolved iron percentage of 97.45% was obtained in the addition of Pioneera L-800 of 1200 ppm at 4.5M sulfuric acid concentration and 15% solid percentage. The addition of biopolymer decreases the activation energy of leaching process from 142.41 kJ/mol to 136.61 kJ/mol and accelerates leaching rate. Kinetic analysis shows that leaching of lateritic nickel ore in sulfuric acid solution at the absence and presence of Pioneera L-800 biopolymer is controlled by diffusion through unreacted solid product layer. <br />