Micro-morphology and Micro-area Chemical Characteristics of the Nickel-carrying Minerals in the Garnierite

摘要

To understand the nickel supergene enrichment mechanism in the lateritic process, we have conducted a preliminary analysis of the micro-morphology and micro-area chemical characteristics of the nickel-carrying minerals of garnierite, sampled from the Kolonodale area of Sulawesi Island in Indonesia. The SEM ＋ EDS analysis shows that, the main nickel-carrying minerals in garnierite are serpentine and talc. The micro-morphology of the talc is fragmented and in piling structure. The micro-morphology of serpentine manifested tubular, fibrous, plate-like and other morphologies, showing the staggered and twisted, mesh-cross and sheet-interwoven structures, etc. The EPMA line scan analysis shows that the mineral types of garnierite samples are mainly of serpentine, talc, olivine and pyroxene debris, containing small amount of quartz, chrome spinel, etc. The Ni content varies a lot in the different minerals, and the nickel-carrying level sorting from high to low is: talc＞ secondary serpentine＞ iddingsite ＞ residual serpentine＞ residual spinel＞ secondary quartz.