The platinum-group minerals in chromitites of the Akanvaara deposit, Northern Finland and in their processing products

The Akanvaara deposit, earlier known mostly for chromitites with proven metallurgical properties and substantial vanadium content, is now reported to contain a range of small (3–10 μm) platinum-group minerals (PGMs). The mineralogy, mineral chemistry and mineral assemblages of PGM indicate primary platinum-group elements (PGEs) fractionation and, probably, late-stage PGE redistribution. The investigations of chromite concentrates prepared earlier for chromite reduction experiments have shown that the amount of PGM in the concentrates is less than in the ore samples. A detailed study on reduced chromite pellets has led to the conclusion that the PGM may have been oxidized during sintering process. This paper suggests further steps for re-evaluation of the PGE-potential of the Akanvaara chromite deposit, including detailed investigations of the position of PGE-enriched horizons, compositional and technological properties of the ores.