Leaching of limonitic nickel from Sorowako with sulfuric acid at atmospheric pressure

Abstract

Indonesia has the largest nickel laterite reserves in the world that it plays an important role in fulfilling the demand for stainless steel, nickel-based alloys, and the issue of using electric cars in the future. Currently, low-grade nickel laterite ore has not been maximally processed into value-added products domestically. The extraction process that is widely applied in the industry for low-grade laterite nickel ore through the hydrometallurgical route, which is the leaching method at atmospheric pressure in a sulphuric acid solution. The characterization of nickel ore from Sorowako has been studied that included water content analysis, sieve analysis, XRF analysis, XRD analysis, and leaching in sulphuric acid solution with agitation method at various leaching times. The results showed that the nickel ore sample from Sorowako had a water content of 5.51% with a dominant size fraction of -4 +14 mesh. XRD and XRF analysis results have shown that the chemical compositions of laterite nickel from Sorowako were Limonitic type of goethite (FeOOH) and quartz (SiO2) with the content of Ni, Co, Mg, and Fe of 1.5%, 0.02%, 0.05%, and 23.82%, respectively. The highest percentages of nickel and iron extract that were obtained at the 12 hour leaching time were 90.01% and 97.11%, respectively.