A CRITICAL STUDY OF TECHNOLOGY DEVELOPMENTS OF NICKEL LATERITE ORES AGITATION LEACHING PROCESSES AT ATMOSPHERIC PRESSURE

• Main Author: Arief Sutandi, Kristoforus
• Format: Final Project
• Language: Indonesia
• Subjects: Metalurgi
• Online Access: https://digilib.itb.ac.id/gdl/view/51379
• Institution: Institut Teknologi Bandung

The hydrometallurgical technology that is considered to be proven for processing low grade nickel laterite ores is the high pressure acid leaching (HPAL) process. However, the HPAL Process requires high investment costs and complex operation. The agitation leaching process at atmospheric pressure (atmospheric agitation leaching /AL) has advantages over the HPAL process, in terms of lower capital costs and energy consumption, easier process control, and lower maintenance costs. However, the AL process still faces various problems, such as low leaching selectivity to iron, slow leaching kinetics, high acid consumption, and high residual acid concentration. The development and modification of the nickel laterite ores agitation leaching at atmospheric pressure are continuously being carried out. In this study, the developments of technologies of laterite ores agitation leaching at atmospheric pressure using various leaching reagents, which include inorganic acids (i.e. sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid) and organic acids are reviewed. Informations regarding the development and modification of nickel laterite ores agitation leaching at atmospheric pressure that had been published in books, journals, patents, project reports, or other sources published in the last 20 years (2000-2020) were collected. These informations were reviewed and studied to determine the advantages and disadvantages of each process. In addition, future opportunities and challenges are also determined for improvement of the performance of nickel laterite ores agitation leaching at atmospheric pressure. Technologies of nickel laterite ores agitation leaching process at atmospheric pressure with inorganic and organic acids have been continuously developed during the last 20 years. There are advantages and disadvantages of various processes that had been developed. The agitation leaching process of nickel laterite ores at atmospheric pressure using hydrochloric acid and nitric acid offer good leaching performance but its commercial applicability is highly dependent on the acid regeneration effectiveness. In sulfate technology, the agitation leaching process of at atmospheric pressure using sulfuric acid with the addition of urea provides good leaching performance but the leaching selectivity of nickel over iron leaching is still to be improved.