Soil Wash Plant: 100 t/h Soil Washing Line In Sudan | LZZG

A soil wash plant turns excavation spoil, muck and construction and demolition waste into saleable aggregate. This one runs in Sudan at 100 t/h is part of our soil wash plant range, and its output is specified to meet EU End-of-Waste criteria rather than landfill acceptance. The line below is the full record: feed limits, cut points, mass balance, equipment list and the water circuit — enough for a plant engineer to judge whether the same arrangement fits their own site.

What a Soil Wash Plant does ?

Soil arrives as a mixture of useful aggregate, silt and clay, organic debris and occasional metal. Washing splits that mixture by size and by settling behaviour, and the split is what decides whether the material is a product or a waste.

• Recovers 4–63 mm gravel and 0–4 mm sand as graded, washed products
• Concentrates everything below 0.063 mm into a small sludge stream that leaves as filter cake
• Removes steel, rebars and nails on the belt, and floating plastics and wood chips on the water surface
• Closes the water loop so the plant runs on make-up water only, not a continuous draw

What it does not do is chemical treatment. Washing is a physical process: it separates clean aggregate from contaminated fines. Where the contamination sits in the fines — heavy metals, hydrocarbons, salts — the wash plant is the volume-reduction step, and the resulting cake still needs the disposal or treatment route its analysis calls for.

Soil Washing Covers Two Different Jobs

Item	Excavation and C&D Soil	Contaminated Site Soil
Input	Muck, spoil, waste concrete, brick, slag	Soil carrying metals, hydrocarbons, salts
Goal	Recover aggregate, cut landfill volume, reach End-of-Waste	Reduce contaminated mass to a manageable fraction
Product	Gravel and sand sold as aggregate	Clean coarse fraction, contaminated fines cake
Decided by	Clay content and lump size	Contaminant distribution across size fractions
This project	Yes — inert waste, EU EoW output	Washing stage only; fines routed out

The distinction matters at quotation stage. A plant sized for inert C&D waste is not automatically a remediation plant, and a remediation plant carries more water treatment and more instrumentation than the aggregate duty needs.

Project Requirement

Item	Specification
Capacity	100 tons per hour, continuous operation for 8 hours per single shift
Feed Materials	Inorganic inert wastes such as muck, waste concrete, bricks and tiles, mine slag, and inorganic silt
Feed Control	Maximum particle size of incoming materials: 300 mm; after pre-screening, feed size is limited to 0–80 mm, with 63–80 mm oversize materials accounting for 10%–20% of the incoming feed
Output Standard	Output materials comply with EU End-of-Waste (EoW) criteria and UNI EN aggregate series standards; finished products can be directly sold as commercial aggregates

Soil Washing Process Flow

Eleven stages, grouped into four duties. Each group has one job, and the plant is stable only when all four are sized to each other.

Group	Stages	What It Settles
Feed and sizing	Feeding → 63 mm classification screen → 63–80 mm crushing circuit → belt magnetic iron removal	Nothing above 63 mm reaches the washer; no tramp metal reaches the scrubber
Washing and classification	Scrubbing and desliming → wet classification (4/10/18/28/63 mm)	Four saleable gravel grades with clay broken off the grain
Fines and sand	0–4 mm fines recovery and dewatering → light organic and ultra-fine sludge separation	Sand recovered instead of lost; plastics and wood taken out of the product
Water and sludge	Closed-loop water treatment → high-pressure filter press dewatering	Clear water back to the wash; sludge out as stackable cake

Stage-by-Stage Detail

1. Feeding and Pre-Screening

A wear-resistant 6 m³ hopper with a variable-frequency feeder and continuous belt weighing. Pre-screening divides the flow into 0–63 mm feed and 63–80 mm oversize. The weighing matters more than it looks: without a measured feed rate, no plant can hold its cut points.

2. Crushing Circuit

All 63–80 mm stone is crushed below 63 mm and returned to the front of the wash, not sold as a separate product. That single decision keeps the output homogeneous, which is what an End-of-Waste declaration depends on.

3. Magnetic Iron Removal

A belt-type permanent magnet pulls rebars and nails out before the scrubber. Cheap protection for equipment downstream.

4. Scrubbing and Washing

A twin-shaft paddle scrubber strips clay agglomerates off the aggregate surface, with 4–20 mA online water flow monitoring. Wear liners and paddles are replaceable items, not a rebuild.

5. 4–63 mm Wet Classification

Wet screening at 4/10/18/28/63 mm cut points produces four commercial gravel grades in one pass. Each grade is washed and dewatered independently so residual moisture and fines content can be held per product, not averaged across the pile.

6. 0–4 mm Fine Sand Recovery

Hydrocyclones separate silt below 0.063 mm from the fine sand; the sand goes to a high-frequency dewatering screen. This stage is where a soil wash plant either makes money or loses it: every tonne of sand that overflows the thickener comes back as disposal cost.

7. Ultra-Fine Sludge and Organics Separation

A turbid slurry mixing tank plus wedge wire screens take out floating plastics and wood chips. All silt below 0.063 mm goes to sludge treatment and is not counted as product. Organic debris is stockpiled separately.

8. Closed-loop Water and Filter Press

A high-efficiency thickener handles flocculation and sedimentation; all overflow clear water returns to the wash. A high-pressure chamber filter press delivers filter cake at 65–75% dry solids. A 50 m³ homogenisation tank buffers continuous washing against intermittent pressing, backed by automatic flocculant preparation and dosing.

The loop is closed in the operational sense: make-up water covers evaporation and the moisture that leaves in the cake, so the plant does not depend on a continuous fresh-water supply and does not discharge process water.

Output and Mass Balance

Stream	Capacity
63–80 mm crushed and returned	10–20% of incoming feed (internal circulation, not for sale)
4–63 mm gravel	40–55 t/h
0–4 mm sand	30–45 t/h
Sludge fines (<0.063 mm)	5–20 t/h
Separated organic waste	<5 t/h

Read the balance as the economics of the plant: 70–100 t/h of saleable aggregate against 5–25 t/h of residue. The line can also absorb short runs of high-clay slag with up to 80% surface soil without stopping, because the buffer tank and hopper are oversized for exactly that.

Partial Equipment List for Soil Washing Plant

Group / Machine	Key Data	Function
Steel hopper 6 m³ + belt feeder + control grid	—	Reception and feeding
Belt conveyor	—	Conveying
Belt magnetic separator	1.5 kW	Iron removal
Drum scrubber with screening, Ø1600×6000	100 t/h	Scrubbing/washing
Turbid-flow repulping tank + organics separation	30 kW	Repulping and organics separation
Hydrocyclone Ø420	15 kW	Fines/sand separation
Hydrocyclone Ø600	30 kW	Sand recovery
Diaphragm metering pumps (chemicals)	0.37 kW ×3	Reagent dosing
Twin-shaft paddle scrubber, 4580 mm rotors	18.5+18.5 kW	Washing of clayey material
Gravel dewatering screen, 1500×3000	30 kW	4–63 mm dewatering
Organics extraction/dewatering screws	4 kW	Conveying/dewatering
Gravel evacuation conveyors	2.2 kW	Product evacuation
Dynamic circular settler Ø12 m, 500 m³	—	Primary clarification
Sludge storage/homogenisation tank 50 m³	5.5 kW	Sludge homogenisation
Clarified-water storage tank 50 m³ + pumps	30+30 kW	Water recycling
High-pressure chamber filter press	45 kW	Sludge dewatering
Automatic flocculant dosing equipment	0.55 kW	Flocculant preparation and dosing
Static secondary settler Ø3 m	7.5 kW	Secondary clarification

How to size a soil wash plant for your site

Five numbers decide the plant, and none of them is the hourly capacity:

Question	Why It Changes the Design
What is the clay and silt percentage?	Under 20% a single scrubbing stage holds; above it the plant needs a second scrub and a bigger thickener
What is the largest lump in the feed?	Sets the hopper grid, the pre-screen aperture and whether a crusher is in the circuit at all
What does the product have to meet?	End-of-Waste, a local aggregate standard or internal reuse — each changes the cut points and the washing intensity
Where does the sludge go?	Cake to landfill, cake to a licensed handler, or reuse as fill decides the filter press size and the cake dryness target
How much water can you take, and can you discharge?	A closed loop needs make-up water only; an open circuit needs a permit and a settling area

Capacity then follows: it is the feed tonnage the plant can hold at those cut points without carrying sand over the weirs or overflowing the thickener.

Soil Wash Plant VS Sand Wash Plant: Not the Same Machine

Item	Soil Wash Plant	Sand Wash Plant
Feed	Mixed spoil, 0–300 mm, with brick, concrete, debris	Sand and fine gravel, 0–10 mm
Core machines	Hopper, pre-screen, crusher, scrubber, multi-deck wet screen	Scrubber or screw washer, dewatering screen, hydrocyclone
Output	Several gravel grades plus sand	One or two sand grades
Typical duty	Divert C&D waste from landfill, produce EoW aggregate	Upgrade sand for concrete or masonry

A soil wash plant contains a sand wash plant inside it. That is why the fines recovery and water treatment sections are the ones that decide whether the whole line is profitable.

FAQ

What Is a Soil Wash Plant?

A soil wash plant is a wet processing line that separates excavation soil and demolition waste into saleable aggregate, sand, and a small sludge residue. It works by size classification and washing rather than by chemical treatment.

Can a Soil Wash Plant Treat Contaminated Soil?

It can be the first stage. Washing removes silt, clay, organics and metal from the coarse fraction, which is usually the cleanest part of the material. Contaminants that sit in the fines are concentrated into the filter cake, and that cake still needs the disposal or treatment route its analysis requires. Chemical and thermal remediation sit outside what a washing line does.

Does the Output Qualify as End-of-Waste?

Not automatically. The plant is specified here to meet EU End-of-Waste criteria and the UNI EN aggregate series, but the declaration depends on the material’s test results and the national competent authority in your jurisdiction. Build the plant to the standard, then prove the product against it.

How Much Water does It Use?

The circuit is closed: thickener overflow returns to the wash, and make-up water covers evaporation plus the moisture leaving in the cake. There is no process water discharge, so the plant needs a make-up supply, not a continuous draw.