Abstract: For a separation into a purified fraction and a polluant concentrate, contaminated soils are ground in a drum to which loose pieces acting like grinding elements have been added and with a net energy input of 4 to 16 kWh per 1000 kg throughput. The speed is 50 to 90% of the critical speed ##EQU1## The suspension discharged from the drum is separated by sieving into a relatively coarse fraction and a relatively fine fraction. The relatively coarse fraction is discharged as a purified fraction and the relatively fine fraction is desludged. The separated sludge is dewatered and is subsequently delivered as a polluant concentrate. The desludged remainder of the finer fraction is dewatered and is subsequently delivered as purified soil.