[en] This article aims to show that the nature of the ilmenite influences its dissolution in hydrochloric acid. The ilmenite concentrate of this study was obtained from the Mining Engineering Department of Istanbul University, Turkey. The source and the method of concentrate preparation were not disclosed to the authors. Physical characterisation of the ilmenite however showed that the sample was a primary rock ilmenite crushed to -45μm to remove the gangue minerals during its beneficiation. The XRF analysis, obtained with a Philips PW2404 XRF instrument, suggests that the ilmenite concentrate from Istanbul University contained higher amounts of Fe, Mg and lower amounts of Ti, Mn and Th compared with Western Australian (WA) ilmenite. The small amounts of Na, Ca, Al and Si were considered to be due to the presence of gangue minerals such as feldspars. A modal analysis of the sample showed the presence of 95.9% ilmenite, 2.7% mafic minerals, 0.6% feldspars, 0.5% discrete hematite grains and 0.3% other mineral phases. A polished section of the ilmenite concentrate was examined in a JEOL Superprobe microanalyser (Model JXA-8900R) which was fitted with an X-ray energy dispersive spectrometer. The EPMA showed that the sample consisted mainly of a magnesium-rich ilmenite.The average magnesium content of this ilmenite was 4.3% MgO and varied within a range of about 2.7% to 5.0% MgO. The manganese content was negligible. The average TiO₂ and total Fe contents were 47.2 and 33.9%, respectively, indicating a near stoichiometric ilmenite composition. Some of the ilmenite grains were richer in titania content than other grains. However, the TiO₂-rich Mg-ilmenite was less common than the Mg-ilmenite. Minor amounts of rutile and leucoxene, typically rich in titania content, also contained 1.6 to 3.7% MgO. A small amount of hematite and titano-hematite were the major iron oxide phases found in the magnesian ilmenite sample. The hematite exsolution lamella, the most striking textural feature of the magnesian ilmenite under the electron microprobe