Leaching method selection for Caldag lateritic nickel ore by the analytic hierarchy process (AHP)

Abstract

Leaching is an important process in hydrometallurgical operations. This process is used to extract metals from the ores by dissolving them in a lixiviant. It is desired that the leaching method is able to provide high extraction rate at minimal capital and operational costs. There are many parameters that can affect the leaching efficiency and thus, the process of selecting a leaching method is complex. In this study, the use of Analytic Hierarchy Process (AHP) method to select an appropriate leaching method for Caldag lateritic nickel ore has been performed. The application of AHP is assisted with the use of ExperChoice 2000 (R) Software. The results shown that heap leaching (HL) is the most attractive leaching method with a rating of 0.592, followed by atmospheric leaching (AL), and high pressure acid leaching (HPAL) with ratings of 0.293 and 0.115, respectively. In addition, sensitivity analyses have been applied to investigate the impact of the main criteria on the alternative leaching methods. It was found that HPAL can be selected when economical main criteria decreased from 76.1% to 16.3%.