摘要 |
<p>In the process, the material freed from coarse components by sieving and crushing is subjected to a distillation at a temperature of 300 to 600 DEG C, preferably to a vacuum distillation (21) at a temperature of 350 to 450 DEG C. The invention proposes that the contaminated material, before it is subjected to the distillation process, is pretreated as follows: a fraction having a particle size above 50 mm is separated off (1) from the contaminated material, crushed (3) to a particle size below 50 mm, together with the fraction produced during the separation and having the particle size below 50 mm subjected to a drying process (6) at a temperature of 100 to 130 DEG C and then crushed (16) to a particle size below 2 mm.</p> |