Mineral matter of tuyere cokes from an operating blast furnace was characterized with emphasis on quantification of silicon bearing phases. Tuyere coke samples were obtained from a medium size blast furnace through core drilling. The core was divided into ten sections of 25 cm each from furnace wall and four regions, bosh region, raceway region, bird's nest region and dead man region. Core material was sieved into different size fractions. Feed coke was annealed in a horizontal alumina tube furnace at 1200, 1400 and 1600°C for 30 minutes under an argon atmosphere to calculate the stack height of carbon crystallite (Lc). Coke minerals were quantified using radiofrequency low-temperature oxygen plasma ashing to prepare a carbon-free mineral sample which was used for XRD measurements. SiC is mainly observed in the bosh and raceway cokes, and is generally accompanied by lower residual quartz amounts. The xifengite content was relatively higher in bosh and raceway region and was not seen beyond birdsnest.
