Mechanical Classification and Dewatering of Harbor Sediments

The objective of this process is to separate contaminated harbor sediments in a high contaminated sludge and low contaminated sand fractions which can be used for road building. Only the high contaminated sludge has to be deposited on a landfill.

1.) Analysis of harbor sediments

The extent of contamination depends on the particle size: Fine particles (dp < 25 µm) account for ~35 %-wt of the mass but more than 80 %-wt of the contamination.

2.) Process flowsheet

The dredged material is classified into a high contaminated sludge fraction and several low contaminated sand fractions.

3.) SolidSim simulation

SolidSim can be used to calculate the process stream data including the contamination by introduction of the size dependent property 'contamination'.

SolidSim allows to predict

• the influence of
  - changes of operating conditions
  - a change of a single unit on the performance of the whole process
• find suitable operating parameters to keep the sand fractions below given contamination limits when the dredged sludge changes
• improve the process by performing simulation runs with variations of the operating parameters or of the flowsheet itself