The reduction behavior and crushing strength of carbon-containing iron ore sinters (SI-C) prepared from coke oven gas (COG) tar have been examined with a quartz-made fixed bed reactor and with a tensile and compression testing machine, respectively. When an as-received iron ore sinter (SI) is heated at 10 degrees C/min up to 600 degrees C in 55% H-2/He, the resulting sample (SI/600) gives a very small, broad pore size distribution profile, the surface area (S-BET) and pore volume (V-BJH) being 1.5 m(2)/g and 0.005 cm(3)/g, respectively. On the other hand, SI-pretreated in 55% H-2/He at 450 degrees C for 4 h (SI-450) provides the pore distribution profile peaking around 10 nm, and S-BET and V-BJH are 4 m(2)/g and 0.02 cm(3)/g, respectively. When carbon-containing iron ore sinters (SI/600-C and SI-450-C) are prepared by pyrolysis of the mixture of the pretreated SI and COG tar, no measurable amounts of S-BET and V-BJH are detectable in any case. The crushing strength of SI-450 is improved significantly by the deposition of tarderived carbonaceous materials into the pores formed during the pre-treatment. In a temperature-programed heat treatment in He, the evolution of CO, CO2 and H2O from the SI-450-C samples start after 600 degrees C, and each rate profile observed shows a large peak around 700-850 degrees C. The extent of reduction of SI-C, SI/600-C or SI450-C is 3, 19 or 55% on SI basis, respectively, and it depends on S-BET and/or V-BJH of the feed sample. (C) 2015 Elsevier B.V. All rights reserved.