Knudsen Bowl

The Knudsen Bowl Concentrator is a centrifugal gravity separation device used for the recovery and concentration of gold and other heavy minerals.
It is especially suitable for small-scale operations, exploration plants, and secondary recovery stages. The system operates in batch mode and is designed for efficient recovery of fine gold from various sources such as alluvial deposits, hard rock ores, and tailings.
Its simple design, low operating requirements, and compact size make it ideal for both field and plant use.

WORKING PRINCIPLE

The concentrator operates using centrifugal force to separate particles based on density.

Process Flow :

• Feed material enters the center of the rotating bowl
• Rotation generates centrifugal force

Heavy particles :

• Move outward and get trapped in the bowl liner

Light particles :

• Are carried away with water as tailings

Concentrate accumulates inside the bowl

Cleaning Process :

• Stop operation
• Remove top section
• Open central plug
• Wash out concentrate using water
• Reassemble and restart

OPERATIONAL MODES

Exploration Mode

Simple setup :

• Screening unit + concentrator
• Used for quick evaluation of deposits

Concentration Mode

Units used :

• In parallel → increase capacity
• In series → improve recovery

LIMITATIONS

• Batch operation (not continuous)

Efficiency depends on :

• Feed size
• Mineral concentration
• Feed rate control
• Throughput may decrease with higher heavy mineral content

Gold Recovery

• Alluvial (placer) gold deposits
• Hard rock gold ores
• Recovery from tailings and dumps

Mineral Processing

• Tin
• Tungsten
• Scheelite
• Cinnabar
• Other heavy minerals

Process Integration

Recovery from outputs of :

• Shaking tables
• Jigs
• Spirals
• Sluices
• Cone concentrators

Capacity :

• Throughput: 3 – 4 tons per hour (TPH)
• Approximate volumetric capacity: 4–5 cubic yards/hour

Feed Parameters :

• Nominal feed size: ≤ 4 mm
• Maximum feed size: 6 – 8 mm (depending on particle shape)
• Alternative reference: ~1/8″ typical, up to 3/16″ if not jagged

Operating Conditions :

• Pulp density: ~30% solids
• Water requirement: ~30 gallons/min (approx.)
• Operation type: Batch process
• Rotational speed: Relatively low (compared to high-G systems)

• Batch operation with easy cleaning and concentrate removal
• Low rotational speed → reduced wear and maintenance
• No requirement for additional water for bed dilation
• Simple and robust construction
• Compact and lightweight design
• Low capital and operating cost
• Bowl geometry optimized for maximum gold retention

Can operate :

• As a single unit
• In parallel (for higher capacity)
• In series (for improved recovery)