Determination of chromium and trace elements in El-Rubshi chromite from Eastern Desert, Egypt by neutron activation analysis

Neutron activation analysis (NAA) is one of the most powerful analytical techniques for multielement determination of rocks. In the present work NAA and HPGe detector γ-spectroscopy was used to determine chromium and 15 minor and trace elements qualitatively and quantitatively from chromite rock samples collected from El-Robshi area in the Eastern Desert, Egypt. The samples were properly prepared together with their standards and simultaneously irradiated by thermal neutrons at the TRIGA Mainz research reactor. Short time irradiation (1-5 min) was used to determine Mg, Ti and Mn. Long time irradiation (6 h) was used to determine Na, Ga, As, La, Sc, Cr, Fe, Co, Zn, Zr, Ce, Ce, Yb, Lu, Hf and Ta. In El-Robshi chromite comprises 18 sites, more than 100 lenses of massive chromite, more than 2700 tons averaging 44% Cr2O3 and the average of 51Cr 40.2%.