Dredged sediments: separating and recovering sand
Ports, reservoirs and canals need dredging, and what comes out has to be managed. Separating sand from silt cuts the volume to treat and frees up reusable material, where testing and regulations allow.
- 30–500 m³/h per machine
- 30 µm the finest cut in the range
- 40+ years with abrasive slurry
The slurry from a dredger is mostly water, with sand, silt and clay in proportions that change from site to site. A desander separates the sand continuously, while the dredger works.
If you are a dredging contractor or manage ports, reservoirs or canals, you know the problem: abrasive slurry, treated continuously, by machines that have to last. It has been our work for more than 40 years.
Why separate
Less volume to manage
Unseparated sediment is all handled the same way, including the clean part.
Reusable sand
If testing allows, the sandy fraction can have a second use, for example beach nourishment.
Fines that are easier to treat
With the sand removed, silt and clay reach settling or the filter press without the most abrasive part.
How it works
- 01
Slurry in
The dredger or a pump brings the sediment, in water, to the plant.
- 02
Screening
The screen holds back shells, gravel and debris.
- 03
Separation
The hydrocyclones separate the sand from the fine fraction.
- 04
Output
The sand comes out concentrated and is stockpiled; water and fines continue to settling or the filter press.
When it pays, and when it doesn't
Separation pays when there is sand in the sediment. Reservoir sediment is often very fine silt and clay: there a desander recovers little, and you need settling or filter presses. That's why we always start from the particle-size curve.
The machines
Sized on the slurry flow and the particle size of the sediment:
SD series desanders
The standard machine for separating sand at high flows.SD series detailsSDS series desilters
When there is a lot of fine sand to recover.SDS series detailsSCD/SCDV series desilters
For smaller sites, with a built-in vibrating screen.SCD/SCDV series detailsPumps and prescreens
To move abrasive slurry and hold back coarse material.Full range
Public programmes and incentives
- Port of Ravenna: construction of a plant to recover 750,000 m³ a year of dredged material started in October 2025; the sand is earmarked for beach nourishment.
- Silted reservoirs: nearly half of Italy's main reservoirs are significantly silted, and some have lost 30–40% of their volume (CESI, 2026). The 2023 drought decree tasked a national commissioner with identifying the dams that urgently need sediment removed.
- Landfill costs more since 2025: the 2025 Budget Law removed landfill disposal from the reduced 10% VAT rate. Separating and recovering the sand cuts the volume to dispose of.
- Incentives for machinery: hyper-depreciation 2026–2028 for goods that meet the 4.0 requirements, Nuova Sabatini for SMEs, and the ZES Unica tax credit for investments in southern Italy.
Why SAICI
- 40+ years and 300+ projects with abrasive slurry.
- Wear-resistant parts: every part subject to wear is made from wear-resistant materials, selected and tested for the duty.
- Spare parts shipped within 24 hours of the order, for all our machines: a plant or a site standing idle while it waits for a part is expensive.
- One supplier for screens, pumps and hydrocyclones.
- Straight answers: if your sediment is too fine, we'll tell you straight away.
Frequently asked questions
Can the recovered sand be reused?
That depends on testing and on the project's permits: the machine separates, the project and the authorities decide where the sand goes. Without separation, though, reuse is much harder.
Does it work on reservoir sediment?
Only if there is enough sand. Reservoir sediment is often silt and clay: with the particle-size curve we can tell you whether it is worth it.
What flows can you handle?
A single machine handles 30 to 500 m³/h; for higher flows, several units work side by side.
What do you need for a quote?
The volume to dredge, the slurry flow, the particle-size curve and where the sand and fines are meant to go.
Let's talk about your dredging project
Send us this information and we'll tell you how much sand can be recovered, and with which machine:
- volume to dredge and length of the works
- slurry flow (m³/h)
- particle-size curve of the sediment
- planned destination of sand and fines
In some cases rental is also possible: if you're interested, ask us.