Recovery of natural stone material from waste residue

摘要

A breaker is used (1) which reduces the waste material to a pourable state. The material is then fed to a conveyor (2) feeding a pre-sorting device (3). In the pre-sorter fine parts are segregated and thrown away. The waste material is then taken by a further conveyor (4) to a processing area. The processing area commences with a burner (5) to which a pipe (6) is connected, which is rotatable around its longitudinal axis. The pipe has first (6.1) and second (6.2) sections. The second section is widened in relation to the first and to it connects a sieve (7). The waste is heated in the burner to temperatures above that for evaporation of water. A relative movement is imparted to the particles which produces a counterpoised friction, until an essential part of the clay and other impurities is separated and removed by the sieve (7).