Most coal-fired power plants handle mill rejects using either hydraulic sluicing systems or mechanical conveyors such as drag chains, belts, or screw conveyors.

Hydraulic systems transport rejects as a slurry using water, moving material through pipelines to settling ponds or dewatering systems. Mechanical systems rely on physical equipment—chains, belts, and rotating components—to move rejects from hoppers to storage or disposal.

These approaches have been widely used due to their simplicity and ability to handle coarse, abrasive material. Mechanical conveyors, in particular, are often selected for heavy-duty applications because they can move large, dense materials through direct contact.

Conventional systems introduce ongoing operational, environmental, and maintenance challenges—especially with abrasive mill rejects.

Hydraulic System Limitations

• High Water Use — Increased cost and complexity

• Environmental Risk — Ash ponds and slurry systems face tightening regulations

• Complex Infrastructure — Pumps, pipelines, and water treatment required

Mechanical Conveyor Limitations

• High Wear & Maintenance — Direct wear on moving parts

• Downtime Risk — Multiple moving parts means more failure points

• Dust & Spillage — Open systems create material loss and dust exposure

Our pneumatic conveying systems provide a fully enclosed, dry solution for mill reject handling—eliminating water usage and reducing reliance on mechanical components.

Using dense-phase pneumatic conveying, mill rejects up to 50mm are transported through a sealed pipeline to a collection silo or storage system. Typical systems can handle capacities up to 30 tons/hour, with existing installations operating continuously for over 10 years with zero unscheduled downtime.

Key Advantages:

• Eliminates Water-Based Handling
  No sluice water, ash ponds, or slurry management

• Reduced Maintenance & Wear
  Fewer moving parts significantly lower maintenance requirements and system downtime

• Enclosed, Dust-Free Operation
  Prevents spillage and minimizes environmental exposure

• Flexible System Layout
  Easily routes around existing equipment and integrates into retrofit projects

• Improved Reliability
  Designed for continuous operation—even when handling highly abrasive materials

• Cleaner, Safer Operation
  Eliminates many of the risks associated with open or mechanical systems

By replacing hydraulic and mechanical systems with pneumatic conveying, plants can reduce environmental risk, lower maintenance costs, and achieve a more reliable, future-ready solution.