Mobile washing plants are designed to process and classify natural aggregates (such as gravel) or recycled materials. The goal is to produce clean, high-quality material suitable for construction, road building, landscaping, or as pure aggregates for asphalt and concrete production.
Unlike dry screening systems, washing plants use water to assist in sorting and cleaning the feed material. This process removes fine particles (such as sand or clay) adhering to the stones, resulting in a cleaner product. At the end of the process, sand and water are separated using a dewatering screen, ensuring minimal waste and efficient water recycling.
The raw material is loaded into a feed hopper using a wheel loader or other equipment. A hydraulic tipping grid prevents any oversize material from entering the mobile washing plant. A conveyor belt transports the material to the washing screen box.
Inside the screen box, the material passes through three screening decks, which separate it into four size fractions. Water is sprayed onto the material through distribution pipes and hoses mounted on the screen box. The screen box is fitted with either regular screen media or special wear-resistant Polyurethane screen media. Polyurethane is a durable and flexible synthetic material commonly used in aggregate washing applications.
Wash water is pumped from a settling pond and distributed across the screen decks. Typical plants process around 100 tons per hour, consuming approximately 1 m³ of water per ton of material. Therefore, water management and reuse of waste water is essential in aggregate washing applications.
After washing, the water mixed with fine sand is collected in a catch-box and directed to an after-treatment system.
After washing, the water—now mixed with sand— is directed to a dewatering system. This is where the magic happens. Separating sand from water is crucial for producing clean fine aggregates and recycling water efficiently. Here are the main technologies used in mobile washing applications:
Ideal for coarser to medium sand products and simple dewatering needs with lower water recovery requirements. For those applications it is a simple and cost-effective solution. Due to the bulky nature of bucket wheels they are more suitable for stationary applications.
This uses high-frequency vibration to remove excess water from sand or aggregates. Ideal for producing a drier product for easier handling and stockpiling. Works well for fine sand that would otherwise be lost in the wash water. Compared to bucket wheels or screw washers, dewatering screens are compact and efficient, making them ideal for mobile setups.
Hydrocyclones separate fine particles and water, sending clean sand to a dewatering screen. Great for improving sand recovery and reducing water loss. They make is easy to recycle water while maintaining a space-efficient footprint compared to large settling ponds.
Modern mobile washing plants often combine hydrocyclones + dewatering screens for maximum efficiency and minimal water loss. These dewatering systems are manufactured by Dernaseer Engineering https://www.dernaseer.com/ or CAB Systems https://cab-group.com/.
The separated water is returned to the settling pond, where small particles settle. 85% of the wastewater can be reused in the washing process. The remaining 15% have to be added from a new water source.
Aggregate Size | Common Use | Industry/Application |
|---|---|---|
0–2 mm | Filler, fine sand | Asphalt mixes, concrete additives |
0–4 mm | Fine aggregate for mortar & concrete | Concrete production, paving |
4–8 mm | Small aggregate for structural concrete | Concrete for floors, precast elements |
8–16 mm | Medium aggregate for load-bearing parts | Structural concrete, asphalt binder |
16–32 mm | Coarse aggregate for heavy-duty concrete | Foundations, road base layers |
32–63 mm | Sub-base and drainage layers | Road construction, landscaping |
>63 mm | Oversize, usually pre-screened dry | Gabions, decorative stone, drainage |
Looking for a mobile washing plant that delivers clean aggregates, efficient water recycling, and maximum productivity? Our team will help you choose the right setup—whether you need just the mobile washing screen or a complete setup we are here to help.
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