In wet Incineration Bottom Ash (IBA) processing, extracting metals is only half the battle. To achieve true zero-waste-to-landfill, the remaining fine slag (0-4mm) must be upgraded into usable construction aggregates. Our IBA Slag Washing Machines are essential for this upgrading process.
Designed to remove surface dust, unburned organic light materials, and soluble salts (such as chlorides), these washers ensure your final slag sand meets stringent environmental building codes. We offer two highly efficient configurations—Wheel Bucket and Spiral (Screw)—to integrate seamlessly into your IBA Sorting Solutions.
I. Wheel Bucket Slag Washer (High-Efficiency Cleaning)
Core Working Principle
Powered by a motor and a robust reduction gear system, the central impeller rotates slowly within the washing tank. As raw, fine IBA enters the tank, the tumbling action breaks the surface tension and scrubs away bonded impurities. A strong water flow is introduced, causing light organics (unburned municipal waste) and dissolved salts to float and exit via the overflow weir. The clean, heavy slag sand is scooped up by the impeller blades, dewatered as it rotates upward, and discharged.
| Performance Features |
Benefits for IBA Processing |
| ✅ Minimal Fine Slag Loss |
The optimized impeller and overflow design ensures excellent cleaning while preventing the loss of valuable fine slag sand, maintaining a stable fineness modulus for construction use. |
| ✅ Isolated Bearing Design |
The impeller drive bearing is completely isolated from the water and abrasive slag slurry, drastically reducing the failure rate and extending equipment life. |
| ✅ Low Power Consumption |
Delivers large-capacity washing per unit time with minimal electricity, ensuring highly economical operation for WtE plants. |
II. Spiral Slag Washer (Heavy-Duty Scrubbing)
Core Working Principle
For IBA with higher clay or sticky ash content, the Spiral (Screw) Washer is ideal. The continuous rotation of the solid spiral blade aggressively mixes and pushes the slag through the water bath. This intense scrubbing creates a slurry with the impurities, which overflows out the side. Meanwhile, the clean slag sand is pushed up the inclined trough, allowing water to drain back down, resulting in a clean, dewatered final product.
| Performance Features |
Benefits for IBA Processing |
| ✅ Integrated Scrubbing & Dewatering |
The long, inclined screw design performs heavy-duty washing and primary dewatering simultaneously in a single, space-saving unit. |
| ✅ Fully Enclosed Transmission |
Prevents corrosive water and abrasive dust from entering the gearbox, ensuring exceptional durability in harsh solid waste environments. |
| ✅ Adjustable Weir Plate |
Operators can flexibly adjust the weir height to control the washing water volume and overflow size, ensuring exact compliance with chloride-removal targets. |
Key Applications in Resource Recovery
- ◾ IBA Aggregate Upgrading: Washing fine bottom ash to remove salts, heavy metal dust, and organics to produce CE-certified secondary construction materials.
- ◾ Construction & Demolition (C&D) Waste: Cleaning crushed concrete and brick fines to produce high-grade recycled sand.
- ◾ Final Washing Stage: Operating in conjunction with Dewatering Screens to deliver the final polish to recovered slag products.
Frequently Asked Questions (FAQ)
Q: Why is it necessary to wash Incineration Bottom Ash?
A: Unwashed bottom ash fines contain soluble salts, chlorides, and sulfates that can corrode reinforcement steel if used directly in concrete. Our slag washing machines dissolve and remove these chemical impurities, alongside unburned organic matter, making the slag safe and compliant for commercial building use.
Q: Should I choose a Wheel Bucket or a Spiral Slag Washer for my WtE plant?
A: It depends on your ash characteristics. If your IBA has a high content of sticky clay-like ash or heavy organic contamination, the aggressive scrubbing of the Spiral Washer is recommended. For standard fine slag where low power consumption and minimal fine sand loss are the priorities, the Wheel Bucket Washer is highly efficient.
Q: How do you handle the dirty wastewater generated from washing slag?
A: We provide complete wet processing solutions. The overflow wastewater from the slag washer is directed to a thickener and then to our Sludge Filter Press. This system separates the toxic sludge cake for safe disposal and recycles clean water back into the slag washer, achieving a zero-liquid-discharge (ZLD) closed loop.
