Mill scale & water recovery
Oil skimmer
Continuously collects rolling oil from the basin surface and separates it from the water.
Mill scale and waste water recovery
Oily mill scale from rolling mills pollutes water and is expensive to dispose of. Our closed-loop system separates the scale from the oil, makes the water reusable and turns the scale into a saleable product.
During rolling, the scale that flakes off the steel surface mixes with cooling water and rolling oil and becomes an oily sludge. It pollutes the water, clogs filters and basins, and needs large amounts of chemicals to treat. In the end, mill scale, a valuable source of iron oxide, is disposed of as waste.
The idea is simple
Separate the scale from the oil, reuse the water, reduce maintenance costs, cut chemical oil treatment by half and sell the mill scale.
How the system works
- 1Pre-settling
Scale-laden water enters the settling basin and coarse scale settles to the bottom.
- 2Oil skimming
Rolling oil on the surface is collected by the oil skimmer and stored separately.
- 3Washing & separation
The twin-screw separator scrapes the scale, removes the sludge and washes it.
- 4Dewatering & compaction
The screw dewaters and compacts the scale; if needed, a belt dryer lowers its moisture.
- 5Filtration & return
Clean water from the sand filter returns to the line in a closed loop.
What comes out
- Clean waterReturns to the process in a closed loop.
- Separated oilCollected separately, less load on treatment.
- Saleable mill scaleWashed and dewatered iron oxide.
Benefits for your plant
Water savings
Water is used again and again in a closed loop.
Less maintenance
Less clogging and wear in basins, filters and pumps.
Fewer chemicals
Aims to cut chemical oil treatment by up to half.
Revenue from waste
Mill scale becomes a saleable product instead of waste.
Green transformation
Less waste and water use, supporting your sustainability goals.
Turnkey delivery
Survey, design, manufacturing, installation and commissioning from one company.
Equipment in the system
Mill scale & water recovery
Twin-screw separator
Scrapes, de-sludges and washes the mill scale, separating the oily sludge.
Mill scale & water recovery
Inclined separator washing system
Washing separator with hydraulic piston adjustable incline and side-to-side motion.
Mill scale & water recovery
Mill scale washing, dewatering & compaction screw
Washes, dewaters and compacts the scale, making it ready for sale.
Mill scale & water recovery
Mill scale drying system (belt dryer)
Lowers the moisture of dewatered scale, with safe temperature control for oily scale (below 50 °C with grease).
Mill scale & water recovery
Sand filter
Filters process water so it can be reused in a closed loop.
Mill scale & water recovery
Oil-water separator & pre-settling
Cleans oily water by settling and separation before treatment.
Example equipment: washing, dewatering & compaction screw
Key values of the pilot screw we engineered for rolling mill applications. Final dimensions are set by the plant's actual mill scale volume and peak loads.
| Capacity | 3,000 kg/h |
|---|---|
| Screw diameter | Ø300 mm |
| Total length | 4,000 mm |
| Drive | 11 kW, VFD controlled (3–9 rpm) |
| Screen | 316L / 304L stainless wedge-wire, 0.5–0.75 mm |
| Wear protection | Hardox / hardfacing |
| Wash water | ≈ 4.5 m³/h, 40 °C |
| Discharge | Adjustable pressure cone |
Mill scale is a valuable raw material
Laboratory samples of rolling mill scale showed a high iron content. Our system aims to keep the iron while reducing oil and moisture, raising the scale's sale value.
- Iron (Fe)66.6% – 68.1%
- Fe₂O₃95.3% – 97.3%
- Oil1.5% – 2.2%
- Moisture4.2% – 4.4%
Engineering your system
We study your mill scale volume, water flow and layout with you and size the system for your capacity. We have engineered closed-loop mill scale washing systems with water recovery for large integrated plants.
What we take on
Site engineering
Measuring the existing line, taking levels, verifying connection points and daily site follow-up.
Design & 3D modelling
Layout, 3D model, fabrication and assembly drawings, bill of materials and revision management.
Fabrication
Separation and dewatering units, conveyors, bunkers, wear plates and steel structures.
Installation & commissioning
Mechanical installation, alignment, testing and tuning, with minimum production downtime.
What we need for a quote
- Daily or monthly mill scale volume
- Oil and moisture content of the scale (analysis report if available)
- Process water flow rate and temperatures
- Existing basin, filter and bunker layout, site dimensions
- How the separated oil and scale will be used
Project timeline
- Site data collection2–4 weeks
- Design & 3D modelling4–8 weeks
- Fabrication2–3 months
- InstallationDuring planned shutdown
- Commissioning & tuning≈ 1 month
Total duration is usually 4–6 months depending on plant size.
Quotes & site surveys
Let's talk about your project
Send us your dimensions, capacity and process details, and we will prepare the right solution and a quote.
Just send us:
- 1Dimensions, capacity and process details
- 2A few photos of the site
- 3Drawings or analysis reports, if any