Thickeners play a critical role in mineral processing.
They separate solids from liquid and produce an underflow stream with a significantly higher solids concentration.
The valve controlling this stream therefore operates in a particularly demanding environment.
What Is Thickener Underflow?
Thickener underflow is the concentrated slurry discharged from the bottom of a thickener.
Depending on the process, it can be dense, abrasive and difficult to handle.
Why Is the Valve Application Difficult?
The combination of:
- High solids
- Abrasive particles
- High density
- Settling
- Potential pressure
- Continuous operation
creates a challenging environment for conventional valve designs.
Valve Design Considerations
A thickener underflow valve should be selected with particular attention to:
Solids concentration
High-density slurry requires a valve designed for the actual duty.
Flow path
Internal restrictions can create areas where solids accumulate.
Sealing
The seat or sleeve arrangement must suit the media.
Materials
Wear resistance and chemical compatibility must be considered.
Actuation
The actuator must provide sufficient force to operate the valve under actual conditions.
Why Valve Failure Is Expensive
A valve problem on a thickener underflow line can affect the wider mineral processing circuit.
This can result in:
- Reduced throughput
- Maintenance downtime
- Production losses
- Emergency intervention
Choosing the Correct Valve
CMO Africa’s GD Series is specifically positioned for extremely abrasive, high-solids slurry duties such as tailings and thickener underflow.
The correct series and configuration should nevertheless be selected according to the specific process conditions.