International audienceThis study aims at extending the previous work of Girolami et al. [11-13] which is still suffering from a lack of reliable predictions for the description of hot, dense suspensions obtained by fluidizing with air a bed of fine solid particles, originally cohesive at room temperature, then released down a rectangular flume. Here, we first present the effective viscosities of the suspensions which increase as a power law of the particle volume fraction Φs. Thus, we show that their rheological behaviour is solely controlled by Φs and its value at packing Φpacking , whatever the material involved in the mixture. Finally, we present a new modeling of the flows runout and highlight that the flows duration is solely controlled by the settling time (i.e. the time necessary for a suspension of a given Φs to settle at a velocity U sed over a distance h exp equals to the expansion height), the initial suspension geometry a, and the key parameter Φs /Φpacking. This prediction allows to distinguish two different flow regimes, with a transition around Φs /Φpacking ≃ 0.85, which seems to be correlated to the variations of the mixture rheology
