A Practical Guide Based on Ore Characteristics & Production Goals
When designing a crushing process, the key question is not how many crushing stages you need, but what each stage must achieve.
Different ores, feed sizes, and final product requirements determine how crushing duties should be distributed across primary, secondary, and tertiary stages.
This guide focuses on real selection logic, not textbook definitions.
1. Start with Feed Size & Mining Conditions (Not the Crusher)
Before selecting any equipment, engineers should evaluate:
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Maximum feed size from blasting
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Ore hardness and abrasiveness
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Moisture and clay content
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Required plant capacity (TPH)
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Final product size and shape requirements
👉 These factors decide how much reduction must happen at each stage, which directly impacts crusher choice and wear cost.
2. Primary Crushing: Handle Oversize Feed with Stability
Primary crushing equipment must prioritize:
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Ability to accept large feed
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Stable operation under uneven feeding
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Low risk of blockage or downtime
Practical equipment choices:
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Jaw crushers → Most common choice for hard and abrasive ores
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Gyratory crushers → Used in high-capacity mines with continuous feeding
Selection tips:
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If feed size is inconsistent → jaw crusher is safer
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If capacity > 1000 TPH and feed is uniform → gyratory crusher becomes economical
⚠️ Common mistake:
Choosing a smaller primary crusher to save initial cost often leads to:
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Frequent liner replacement
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Reduced downstream efficiency
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Higher total operating cost
3. Secondary Crushing: Balance Reduction Ratio & Wear Cost
The secondary stage is where energy efficiency and wear cost start to matter most.
Typical choices:
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Cone crushers → For hard, abrasive materials
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Impact crushers → For softer or less abrasive stone
How to decide:
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Hard rock + high abrasiveness → cone crusher
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Medium hardness + shape requirement → impact crusher
For mining applications, cone crushers dominate secondary crushing due to:
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Better liner life
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Stable product grading
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Lower long-term wear cost
👉 This stage often determines annual wear parts budget.
4. Tertiary Crushing: Control Final Size & Shape
Tertiary crushing is selected only if final product requirements demand it.
Common tertiary equipment:
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Short-head cone crushers → Precise size control
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VSI crushers → Excellent particle shape for aggregates
Use tertiary crushing when:
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Final size < 10–20 mm is required
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Shape is critical for downstream processing
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Grinding load needs to be reduced
⚠️ Not every plant needs tertiary crushing.
Adding this stage without clear demand increases:
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Power consumption
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Wear parts usage
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Maintenance workload
5. Typical Equipment Selection Matrix
| Crushing Stage | Ore Type | Recommended Equipment |
|---|---|---|
| Primary | Hard / abrasive | Jaw Crusher |
| Secondary | Hard rock | Cone Crusher |
| Tertiary | Fine size control | Short-head Cone / VSI |
6. How Proper Selection Reduces Wear Parts Cost
Correct stage allocation:
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Reduces overloading of secondary crushers
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Improves liner utilization rate
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Extends wear parts service life
This is why many mines focus on optimizing crushing stages rather than upgrading a single crusher.
Final Thought
Effective crushing equipment selection is about process balance, not individual machines.
A well-designed crushing circuit always delivers:
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Lower operating cost
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Longer wear parts life
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More stable plant performance
