Longitudinal micrometric separator for classifying solid particulate materials

An apparatus for the classification of solid particulate materials, comprising a micrometric separator that includes an outer casing having an inflow opening and an outflow opening for the solid particulate materials, a collection chamber at a bottom of the outer casing, as well as a sliding support for the solid particulate materials, the sliding support extending substantially along a longitudinal drawing axis and arranged so that said particulate material is conveyed in the direction of said longitudinal drawing axis by a forced fluid flow, said sliding support comprising at least one first inclined wall, lying in a plane parallel to the longitudinal drawing axis, and at least one dropping channel with axis parallel to the longitudinal drawing axis and connected to a side end of the same inclined wall, the other side end of said at least one first inclined wall being set at a distance from internal surfaces of said casing.