Perovskite type titanium-bearing blast furnace slag (TBBFS) and sulphate-modified titanium-bearing blast furnace Slag (SO42-/TBBFS) photocatalysts were prepared by the high-energy ball milling method at different calcination temperature. The photocatalytic were characterized by XRD, FTIR, UV-vis diffuse reflectance spectra and SEM measurements. The photocatalytic activities of the different catalysts were evaluated by the photocatalytic reduction of Cr(VI) under UV-vis light irradiation. For the phatocatalytic reduction of Cr(VI), the photocatalytic activities of TBBFS catalysts were found to be strongly dependent of the calcination temperature and TBBFS calcined at 700 degrees C showed a higher photocatalytic activity compared to other TBBFS catalysts. In contrast, sulphation of TBBFS improved the photocatalytic activities of SO42-/TBBFS catalysts. At low calcination temperature, the photocatalytic activities Of SO42-/TBBFS catalysts were markedly higher than TBBFS prepared under high calcination temperature, suggesting that the presence of surface SO42- favored the photocatalytic reduction of Cr(VI). (C) 2008 Elsevier B.V. All rights reserved.