A study has been undertaken to identify the source of coke fines sampled from the deadman area of the blast furnace. Using measurements of the coke crystallite dimension LC, it was established that some of the fines found in the deadman area of a blast furnace were not simply the degradation products of the lump coke in this area. The LC was measured using standard X-ray analysis techniques. The coke fines had a higher LC than the coke lump and therefore have experienced a higher maximum temperature than the associated coke lump. This finding has been interpreted as at least some of the coke fines being blown into the deadman area (lower temperature region) from the raceway by the high velocity hot blast.