In this work, two different consolidation techniques were used to obtain AIN samples: slip casting and dry pressing of granules obtained from aqueous suspensions by freeze granulation. The green samples were sintered at a temperature (1750 degrees C) lower than those usually used (> 1800 degrees C), using CaF2 and YF3 as sintering aids. The microstructural features were analysed by scanning electron microscopy (SEM) and the crystalline phases formed were identified by X-ray (XRD). Full dense AIN-based ceramics were obtained from both consolidation techniques; however the thermal conductivity values were quite different. The presence of carbon in the samples derived from the freeze granulated powder containing organic processing additives de-waxed in an inert atmosphere revealed to be helpful in the cleaning of oxygen present at the grain boundaries and consequently, for enhancing the thermal conductivity.