Geochemical constraints on the mobilization of Ni and critical metals in laterite deposits, Sulawesi, Indonesia: A mass‐balance approach

Indonesia is one of the largest Ni ore producers in world and also expected to be an important potential source some critical metals (e.g., Co, Sc, rare-earth elements, platinum-group elements). However, few studies have examined laterite deposits this country. In study, we investigate enrichment accumulation four profiles with varying degrees serpentinization weathering intensity Soroako Pomalaa mining areas Sulawesi, Indonesia. We integrate geochemical evaluation a mass-balance approach mineralogical analysis better constrain factors influencing mobilization during lateritization. Nickel contents saprolite horizon that are strongly weathered developed over serpentinized peridotite higher than those weakly unserpentinized harzburgite. The bulk horizons related Ni-bearing Mg-phyllosilicates, which suggests remobilization main control on profiles. Mass-balance calculations reveal amounts gained Fe positively correlated. This relationship indicates redistribution likely controlled by aging goethite (dissolution/recrystallization) involving ligand-promoted dissolution organic matter and/or reductive microbial activity near surface. Critical show specific horizons. Enrichments Co elements influenced formation Mn-oxyhydroxides oxide zone contrast, Pt, Pd residual patterns, grades mainly their initial bedrock. positive correlation between Sc Fe, as reported for other deposits. Among metals, studied comparable values from worldwide.