Segregation process of water-granular mixtures released down a steep chute

The objectives of this contribution are to analyse and quantify the segregation process of water saturated mixtures flowing down steep chutes. Experiments were carried out using two granular mixtures, a steep chute of variable length and a collecting box divided by sectors, in which the flowing material freely falls down at the chute outlet. The flow characteristics, the filling in time of the box itself, the grain-size composition of the box content with varying the distance from the chute outlet are examined by means of laser level transducers, image analysis and sieving. Segregation is effective and rapid along the flow direction, showing a modest dependence on mixture grain-size composition. The grain-size composition profile in time is reconstructed, showing coarser particles concentrated at the flow front, on the flow surface and at the sides, whereas fine fractions prevail at the tail and at the bottom.