The principal aims of this project were to study the blast furnace hearth and raceway behaviours in case of low coke and high coal rates operations. The different partners of this project have used their own possibilitiesand devices installed on several industrial blast furnaces. Using the tuyere coke sampling devices, it has been established that : - with coal injection rates ranging from 50 to 200 kg/thm, significant differences were apparent in the drill core structures. In the cases of lower coal injection rates, the drill cores incorporated lower levels of coke fines and iron/slag and were much less compacted than those achieved in cases of high coal injection rates. With high coal injection, the fines content increases just behind the bird nest ; - with high coal injection the raceway length becomes lower showing that the permeability of the dead man boundary becomes also lower ; - the fines sampled along the coal along the tuyere radius when using different coke qualities did not show any accumulation of unburnt coal in the dead man or at the outer shell of the dead man. However, the fines are made of three carbon phases with different level of organisation as graphite and coke. The graphite content in the fines was higher with high coal injection rates, near the raceway and in the smaller fraction. Nevertheless, the origin of the graphite fines is till now uncertain ; - the study of the unburnt char by sampling dust and gas at different positions along the height at the wall and the radius at the top of the furnace when using different coke qualities showed very different results : - the Coke contents in dust rise in the blast furnace from top to bottom in accordance with the increasing thermochemical demand on the coke, when using feed coke with low CSR values. In the case of using coke with high CSR values there is no increase in the Cake content in the dust, i.e. this coke shows a lower degradation mainly in the lower part of the furnace. This has been also confirmed by calculation of the coke degradation inside the blast furnace issued from coke core borings results. More over, hot strength measurements on coke from the tuyere level show higher values with higher CSR values of feed coke in the raceway, in the transition zone and in the dead man. This fact is of great importance because the stress on coke is not finished in the tuyere level ; - in the case of centre coke charging operations, the maximum C c o a l contents in the dust appear in the lower furnace area and in the upper shaft. Both maximum contents are attributable to transverse flows from the furnace centre, where the highest concentrations of unburnt coal particles are measured. The trials with feed coke with a higher hot strength show lower C c o a l contents in the dust despite of higher coal rates. This means a more uniform gas flow when charging cokes with high CSR values.