Ultramafic Inclusion in the Pozzomaggiore Area: Chimical-mineralogical Chraracterization and Mineral Processing

The paper describes the results of chemical and mineralogical characterisation studies and mineral processing trials conducted for assessing the feasibility of beneficiating an alkaline basalt containing peridotite nodules cropping out in the Pozzomaggiore area in NW Sardinia. A detailed mineralogic study, carried out by means of XRF, XRD and electron probe microanalyses, showed the nodules to be composed essentially of dominant olivine, ortho- and clinopyroxenes with accessory spinel. Quantitative mineralogic composition was determined by pure mass balance method and a modified version developed during this work. Mineral processing tests performed using grinding as well as classification and magnetic separation processes, obtained a nodule-free basalt product and an olivine and pyroxene concentrate suitable in the production of abrasives.