Spiral Classifier

High Efficiency Mineral Classification Equipment for Ore Dressing Plants

A Spiral Classifier, also known as a Screw Classifier, Mineral Classifier, or Mechanical Classifier, is an essential wet classification equipment used in mining and mineral processing plants. It separates coarse particles and fine particles based on the difference in settling velocity and gravitational settling characteristics in slurry.

The equipment is widely applied in closed-circuit grinding systems with ball mills, where it efficiently separates qualified fine particles from coarse sand and returns coarse particles back to the grinding mill for further size reduction. It is also commonly used for ore washing, desliming, dewatering, sand recovery and slurry classification in metal and non-metal mineral processing plants.

Our heavy-duty Spiral Classifiers are designed for continuous operation under demanding mining conditions, offering reliable performance, simple maintenance, low operating cost and accurate particle size control.

Working Principle of Spiral Classifier

The Spiral Classifier operates through the principle of hydraulic classification and gravitational settling.

When mineral slurry enters the settling tank, coarse particles with higher density settle faster to the bottom, while fine particles remain suspended and overflow with water. The rotating spiral blade continuously transports settled coarse materials upward along the inclined tank and discharges them as sand return products.

The overflow containing qualified fine particles flows into the next stage of mineral processing, while coarse sand is recycled back to the grinding circuit.

By adjusting parameters such as:

• Overflow weir height
• Spiral rotation speed
• Feed slurry density
• Settling area design

the classification cut size and overflow quality can be effectively controlled.

Types of Spiral Classifier

1. High Weir Spiral Classifier

High Weir Spiral Classifier is mainly designed for coarse particle classification applications.

The spiral blade partially extends above the slurry surface, providing a larger settling area and stable operation.

Typical applications:

• Primary grinding classification
• Iron ore beneficiation
• Copper ore processing
• Gold ore processing
• Lead-zinc ore separation

Recommended classification range:

Approximately 0.15–0.4 mm particle separation

2. Submerged Spiral Classifier

Submerged Spiral Classifier is designed for fine particle classification.

The spiral blades are completely submerged below the slurry surface, increasing the settling area and improving fine particle recovery.

Typical applications:

• Secondary grinding circuits
• Fine mineral classification
• Desliming operations
• Slurry concentration control

Recommended for:

Fine particle separation below approximately 0.15 mm

3. Single Spiral & Double Spiral Classifier

According to processing capacity requirements, Spiral Classifiers can be supplied as:

Single Spiral Classifier

Suitable for:

• Small and medium processing plants
• Lower capacity applications
• Flexible mineral processing systems

Double Spiral Classifier / Twin Spiral Classifier

Suitable for:

• Large-scale concentrators
• Higher throughput requirements
• Continuous mining operations
• 

Applications of Spiral Classifier in Mining Industry

Closed-Circuit Grinding Classification

Spiral Classifier is widely used together with ball mills to create a closed grinding circuit.

It separates:

• Qualified fine mineral particles → next beneficiation stage
• Coarse particles → returned to ball mill for regrinding

This improves grinding efficiency, reduces over-grinding and helps optimize mineral recovery.

Ore Washing and Desliming

In sand and mineral washing plants, Spiral Classifier removes unwanted clay, mud and fine impurities.

Common applications:

• Silica sand washing
• Quartz processing
• Kaolin purification
• Feldspar processing
• Aggregate washing

Dewatering and Sand Recovery

The equipment can also function as a Spiral Dewaterer or Dewatering Spiral for recovering valuable solids from slurry.

Advantages include:

• Reduced moisture content
• Improved material handling
• Higher product recovery

Mineral Processing Applications

Spiral Classifiers are widely used for:

• Gold ore beneficiation
• Copper ore processing
• Iron ore concentration
• Lead-zinc ore separation
• Lithium ore processing
• Phosphate beneficiation
• Manganese ore processing
• Silica sand classification
• Coal washing plants

Key Advantages of Our Spiral Classifier

1. Heavy-Duty Mining Design

Designed for harsh mineral processing environments with reinforced tank structure, strong spiral shaft and durable transmission system.

Suitable for long-term continuous operation in mining plants.

2. High Classification Accuracy

Optimized settling area design improves:

• Overflow quality
• Fine particle recovery
• Particle size separation accuracy

3. Wear-Resistant Spiral Components

The spiral flights are equipped with replaceable wear-resistant components to extend service life.

Optional wear materials include:

• High chrome alloy
• Ni-hard materials
• Polyurethane wear shoes

4. Reliable Submerged Bearing System

The submerged bearing assembly adopts sealed lubrication design to reduce contamination and improve operating stability.

Benefits:

• Longer bearing life
• Lower maintenance frequency
• Reliable operation under slurry conditions

5. Easy Operation and Maintenance

Simple mechanical structure with fewer moving parts makes Spiral Classifier easy to install, operate and maintain.

Wear parts can be replaced quickly, reducing downtime and maintenance costs.

Technical Specifications

Specifications can be customized according to customer requirements, mineral properties and plant capacity.

Why Choose Our Spiral Classifier?

Compared with traditional classification equipment, our Spiral Classifiers provide:

• Stable mineral separation performance
• Lower energy consumption
• Long service life
• Easy spare parts replacement
• Customized solutions for different ores

We provide complete technical support including:

• Equipment selection
• Process optimization
• Customized design
• Export packaging
• Installation guidance

RFQ Request

Looking for a reliable Spiral Classifier Manufacturer or Supplier for your mining project?

Please send us your requirements:

• Mineral type
• Processing capacity (TPH)
• Feed particle size
• Required overflow size
• Working conditions
• Existing grinding circuit information

Our engineering team will recommend the most suitable High Weir Spiral Classifier or Submerged Spiral Classifier solution for your application.

Contact us today for a competitive quotation and professional mineral classification solution.

Product Summary

Spiral Classifier is a reliable mineral processing machine designed for wet classification, ore washing, desliming and dewatering applications. With high weir and submerged designs, it provides accurate particle separation and stable operation for mining plants worldwide.