Hydrocyclones and desanders for soil washing
In soil washing, soil is washed with water and split by particle size: clean sand is recovered, while contaminants stay concentrated in the fine fraction. The heart of the process is separation: screens, hydrocyclones and pumps, the machines SAICI has built for more than 40 years.
- 40+ years separating abrasive slurry
- 30 µm the finest cut in the range
- 30–500 m³/h per machine
Contaminants bind mainly to silt and clay. Separating the sand well means treating or disposing of only the fine fraction and recovering the rest, where testing allows.
On foundation sites these machines handle abrasive material every day and move from job to job: the same conditions as a mobile soil washing plant.
Who it's for
Remediation contractors
They move mobile plants from site to site, often as the environmental division of a foundation contractor.
Plant builders
They need a reliable separation section to build into their lines.
Fixed soil treatment plants
They want to recover more sand or raise throughput.
How separation works
- 01
Screening
The soil, broken up in water, passes over the screens: gravel and coarse material leave straight away.
- 02
Pumping
Wear-resistant slurry pumps feed the sand and fines to the hydrocyclones.
- 03
Separation
The hydrocyclones split the sand from the fine fraction, where the contaminants concentrate.
- 04
Closing the loop
The sand comes out concentrated; water and fines go to clarification and the filter press, and the water goes back into circulation.
What we supply, and what we don't
We supply the separation section: screens, hydrocyclones, pumps and tanks. We don't build turnkey plants or run sites: permits and operation stay with the contractor. Soil washing pays on sandy and gravelly soils; if yours is very clayey, we'll tell you first.
Machines for the separation section
The right cut point depends on soil testing and recovery targets: we define it with the plant designer.
SD series desanders
To separate sand at high flows.SD series detailsSDS series desilters
To recover fine sand as well.SDS series detailsSCD/SCDV series desilters
For smaller flows, with a built-in vibrating screen.SCD/SCDV series detailsPumps and prescreens
Pumps for abrasive slurry and prescreens for coarse material.Full range
Public programmes and incentives
- A long backlog: Italy has more than 16,000 active remediation procedures (ISPRA) and 42 Sites of National Interest (SIN). The PNRR earmarked €500 million for the remediation of orphan sites.
- 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.
- Built for site work: machines used to being assembled and moved from job to job.
- One supplier for screens, hydrocyclones and pumps.
Frequently asked questions
Do you supply complete soil washing plants?
No. We supply the separation section and work alongside whoever designs and builds the complete plant, including clarification and the filter press.
What particle size do your hydrocyclones cut at?
Our ranges work with a nominal cut of 45 µm (SD) and 30 µm (SDS and SCD/SCDV). The plant's cut point is chosen from soil testing; the finest fraction is treated downstream.
Can the machines be moved from site to site?
Yes. They are designed for foundation sites, where they are assembled, dismantled and moved from job to job.
What do you need for a quote?
Flow or tonnes per hour to treat, a particle-size curve or a soil sample, the type of contamination and the expected length of the job.
Let's talk about your plant
Send us this information and we'll propose the right separation section:
- flow (m³/h) or tonnes per hour to treat
- particle-size curve or a soil sample
- type of contamination
- length and location of the job
In some cases rental is also possible: if you're interested, ask us.