Abstract: A device for hydraulic conveyance of loose materials comprises a vertical chamber having a cylindrical side surface and hemispherical a bottom and a cover and is provided with four respective pipes for liquid discharge, loose material charging, feeding the pressure liquid flow and slurry discharge in an upward flow. The pipes are held to the hemispherical cover and are arranged coaxially in such a manner that the loose material charging pipe is accommodated inside the liquid discharge pipe, the pressure liquid flow feeding pipe is accommodated inside the loose material charging pipe, and the slurry upward flow discharging pipe is accommodated inside the pressure liquid flow feeding pipe, all of the pipes being arranged coaxially with the longitudinal axis of the chamber and having some of their portions located inside the chamber. The length of the portions mentioned above increases consecutively from the liquid discharge pipe towards the slurry upward flow discharging pipe.

Abstract: A ball-tube mill in which an inclined wall dividing the mill into coarse and fine grinding chambers occupied by grinding bodies has through holes for the passage of the material being ground provided in a portion of contact of the surface of the inclined wall with the grinding bodies present in the coarse grinding chamber. The through holes have a length much greater than their width with their elongated side running in parallel with an outer contour of the inclined wall.