Abstract

Coarse rutile with some grains exceeding 32 mm was recovered from regolith excavated from three pits (ABC) at Ebensuk. The rutile concentration ranges from 2.53 kg/m3 of regolith material in Pit C to 2.83 kg/m3 in Pit B with an average of 2.66 kg/m3. The rutile is black, longitudinally striated, with a metallic to adamantine luster and hard. Results of grain size (Z) analysis show that the rutile crystals range in size from 4mm to Z≥32 mm. The grains are predominantly concentrated in the 16≤Z<32 mm size grade with a wt% of 48.3 followed by Z≥32 mm and 8≤Z<16 mm size grade with 23.1 wt% and 22.8 wt% respectively.  Results of geochemical analysis by XRF technique reveal that the rutile in the area is of high quality, with a TiO2 content > 96 wt%, and subordinate Fe2O (2.2-3.1 wt%), and minor amounts of Al2O3, SO3, K2O P2O5 and Mn2O3  for all the samples analyzed, and meets international specifications for economic rutile ores. The rutile must have been derived through weathering of the underlying gneisses and their coarse nature is probably indicative of a possible source from granite pegmatite veins occurring in the gneisses outcropping in the study area.

Key words: Coarse rutile, geochemistry, high quality, regolith, grain size.