Crushers are fundamental equipment in the mining, construction, and aggregate industries. Their primary role is to reduce the size of raw materials to a specific particle size suitable for further processing or direct use. For many construction and aggregate projects, the requirement is to produce output material around 20mm in size, which is commonly used in road base, concrete aggregate, and railway ballast. This analysis explores the types of crushers capable of producing 20mm material, their working principles, advantages, and application areas.
Types of Crushers Suitable for 20mm Material
1. Jaw Crusher
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Working Principle: Uses compressive force by pressing material between a fixed and a moving jaw.
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Capability: Primary crushers can reduce large rocks (up to 600–1200mm feed size) to smaller sizes. With proper adjustment of the discharge opening, a jaw crusher can produce output close to 20mm, though often a secondary stage is required for uniform sizing.
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Best Use: Suitable as a primary crusher in mining and construction, feeding material to secondary crushers for final 20mm output.
2. Cone Crusher
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Working Principle: Uses a rotating cone inside a crushing chamber. Material is compressed and broken down into smaller pieces.
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Capability: Highly effective for producing 20mm aggregate directly, especially from medium-hard to hard materials such as granite, basalt, or limestone.
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Best Use: Secondary or tertiary crushing where precise and uniform 20mm output is required.
3. Impact Crusher
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Working Principle: Uses impact force; material is struck by blow bars and thrown against impact plates.
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Capability: Can produce well-shaped aggregates around 20mm. Adjustable settings allow control of output size.
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Best Use: Particularly effective for softer to medium-hard materials, producing high-quality aggregates with good particle shape.
4. Vertical Shaft Impact (VSI) Crusher
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Working Principle: Material is accelerated and projected against a crushing chamber, causing it to break into finer particles.
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Capability: Produces highly consistent 20mm and smaller aggregates, often used in sand making.
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Best Use: Ideal for final shaping where cubical 20mm aggregates are required in concrete or asphalt production.
Key Factors Affecting 20mm Crushing Performance
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Feed Size: Larger feed requires primary crushing before secondary machines refine the material to 20mm.
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Material Hardness: Harder materials (granite, basalt) often require cone crushers, while softer ones (limestone) can be processed by impact crushers.
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Crusher Settings: Discharge opening and rotor speed must be adjusted to consistently achieve 20mm output.
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Capacity Requirements: Machines are available in different tonnages, from small-scale 50 TPH units to large 500+ TPH plants.
Applications of 20mm Crushed Material
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Concrete production: 20mm aggregate is a standard size for reinforced concrete.
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Road construction: Used as base course and surface dressing aggregate.
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Railway ballast: Requires strong, angular 20mm aggregates for stability.
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Asphalt production: Ensures proper mix design and durability of road pavements.
A crusher capable of producing 20mm material can be chosen based on the hardness of feed, required capacity, and end-use application. Typically, a jaw crusher (primary) followed by a cone or impact crusher (secondary/tertiary) provides the most efficient solution. For shaping and precise grading, a VSI crusher may be added to the circuit. Selecting the right machine ensures cost efficiency, consistent quality, and suitability for construction and industrial applications.