Hydroseparation technology applied to PGE mineralization in CHR-2 chromitite, Niquelandia layered intrusion, central Goias, Brazil

摘要

An example of new hydroseparation technology as applied to the investigation of PGE mineralization in the CHR-2 chromitite of the layered intrusion of Niquelandia (central Goias, Brazil) is presented. Use of the HS-01 hydroseparator allows the preparation of <44, 44-75 and 75-120 mum products with a weight of 5-7 mg, which are concentrated by a factor of 10000 times and more from an initial 50-10000 g sample of 'heavy' accessories, and it is particularly useful for the concentration of platinum-group minerals (PGM). It is an environmentally friendly operation in which the water flow regulates the process of concentration. The mineral phase sensitivity can reach 0.1 ppm of the phase containing the heavy element.PGM and Au- and Ag-bearing minerals from the CHR-2 chromitite were examined in polished sections of 'heavy' products. The compositions of the mineral species, sizes of individual grains and photographs of the PGM and Au- and Ag-minerals, were obtained by scanning electron microscopy (Camscan-4DV, Link AN-10000 and Microspec-4). Mineral assemblages and the interrelations between the PGM and the other minerals were reconstructed. This key information on PGM in the 'heavy' concentrates was compared with that obtained from polished sections of typical CHR-2 ores.