Mineralogical and Textural Influence on Cu Grade in Concentrates, Andina Division, Codelco, Chile

摘要

Mineralogy and texture of both the ore and gangue phases are critical to the flotation recovery processof Cu. In this study, mineralogical and textural factors were analyzed as the main influence on Cugrade on rougher concentrates. Data available for this investigation includes QemScan results (PMABMA)and flotation tests of feed, concentrate and tail samples. The analysis of total samples showsthat the most critical mineralogical variables on Cu grade in concentrates are chalcopyrite content infeeds (positive correlation), pyrite content in feeds (negative correlation) and muscovite-sericitecontent in feeds (negative correlation). Textural variables evaluation indicates that the presence ofCu sulphides up to 80% liberated favors a higher Cu grade on rougher concentrates. Moreover, thereis a positive correlation between the content of fine Cu sulphides particles (<37 μm) and Cu grade inconcentrates. The analysis of grouped samples by UGM (Recovery Geometallurgical Units) indicatesthat the common factor between the four UGMs studied is the negative correlation between pyritecontent in feeds and Cu grade in concentrates. Additionally, Cu sulphides liberation above 80 %shows a positive correlation with Cu grade in concentrates in all samples, except those from UGM-3.Principal components analyses suggest that Cu grade in concentrates are related mostly to textures;pyrite in feeds is mainly related to muscovite-sericite in feeds (phyllic alteration effect?); and claysbehave like an independent variable.