Something you should to know, when choosing a suitable impact crusher as a secondary crusher

When choosing a suitable impact crusher as a secondary crusher, you need to consider the output, discharge requirements, feed size and material characteristics. The following are specific steps and precautions to help novices complete the selection:

1. Clarify key parameters

(1) Output requirements

Calculate the target output: determine the processing volume required by the production line per hour (for example, 100-300 tons/hour). The capacity of the impact crusher should be slightly higher than the actual demand to avoid overload operation.

Matching equipment specifications:

Small impact crusher (such as PF-1210): capacity 50-150 tons/hour, suitable for small and medium-sized sand and gravel plants.

Medium impact crusher (such as PF-1315): capacity 150-300 tons/hour, suitable for medium-sized production lines.

Large impact crusher (such as PF-1820): capacity 300-600 tons/hour, suitable for large mines or aggregate projects.

(2) Discharge requirements

Particle size and particle shape:
If the finished product needs to be used as high-grade concrete aggregate, select a multi-cavity impact crusher (such as a three-cavity design) to ensure that the discharge particle shape is a polygonal cube and reduce the needle-like shape.
Adjust the gap between the impact plate and the hammer: the smaller the gap, the finer the discharge (for example, adjusting to 20-50mm can obtain a 0-30mm finished product).
Grading control: If a multi-graded finished product is required (such as 0-5mm, 5-10mm, 10-20mm), a multi-layer vibrating screening device is required.

(3) Feed size

Adapt to the material after one-stage crushing: If the maximum discharge of one-stage crushing (such as a jaw crusher) is 400mm, a impact crusher with a feed port size ≥500×350mm (such as PF-1320) should be selected.
Pre-screening suggestions: If the feed contains a lot of fine material, a pre-screening device can be configured to reduce the ineffective work of the impact crusher.

2. Material characteristics analysis

Hardness:

Medium-hard materials (limestone, dolomite): impact crusher is the first choice, taking into account both particle shape and production capacity.

High-hard materials (granite, basalt): cone crusher is recommended. If you insist on using impact crusher, you need to use high-chromium plate hammer and shorten the maintenance cycle.

Humidity and viscosity:

Wet and sticky materials are easy to clog the impact crusher. It is necessary to reduce the feed humidity or choose a model with heating function.

3. Equipment selection steps

Step 1: Determine core parameters
Example: A production line requires a production capacity of 200 tons/hour after secondary crushing, a feed particle size of ≤300mm, and a discharge of 0-30mm with excellent particle shape.

Model selection: PF-1315 impact crusher (processing capacity 120-280 tons/hour, feed size ≤350mm, and adjustable discharge particle size).

Configuration optimization: three-chamber design + hydraulic cover opening device (easy to maintain plate hammer and impact plate).

Step 2: Verify adaptability
Feed adaptability: The first stage of crushing is 250-300mm, and the maximum feed of PF-1315 is 350mm, which meets the requirements.

Capacity verification: The theoretical upper limit of PF-1315 capacity is 280 tons/hour, and the actual capacity is 224 tons/hour at 80% efficiency, which meets the demand of 200 tons.

Step 3: Wear-resistant parts and cost accounting
Ball hammer life: When crushing granite, the life of high-chromium hammer is about 3000-5000 tons/set, and the cost per ton needs to be calculated.

Energy consumption comparison: The power consumption of impact crusher is about 15% lower than that of cone crusher, but the wear-resistant parts are replaced frequently, and the comprehensive operating cost is required.

4. Brand and after-sales

Domestic brands: such as Shanghai Shanmei and Liming Heavy Industry, with high cost performance and fast after-sales service response.

International brands: such as Sandvik and Metso, the equipment is durable but expensive, suitable for large projects with sufficient budget.

Key services: Ensure that the supplier provides free commissioning, operation training and wear parts inventory support.

5. Practical application cases

Case 1 (limestone):

Feed: ≤350mm (from jaw crusher).

Discharge: 0-30mm (for commercial concrete).

Selection: PF-1315 impact crusher, equipped with three chambers + hydraulic adjustment system, with a stable production capacity of 220 tons/hour.

Case 2 (granite):

Feed: ≤300mm.

Discharge: 0-25mm (needs excellent particle shape).

Selection: PF-1320 impact crusher, using dual motor drive + high chromium alloy plate hammer, but the crushing cost per ton is 20% higher than that of cone crusher.

6. Common misunderstandings

Misunderstanding 1: Blindly pursuing high production capacity, ignoring the feed size limit, resulting in equipment blockage.

Misunderstanding 2: Ignoring the hardness of the material, using the impact crusher to crush high-hardness materials, resulting in the replacement of the plate hammer once a month, and the cost increased dramatically.

Misunderstanding 3: No adjustment space is reserved, the equipment is running at full capacity, and it cannot cope with future production increases.

Summary and suggestions
Beginner operation checklist:

Clearly define the three parameters of output, feed and discharge.

Choose the crushing principle (impact crushing or lamination crushing) according to the hardness of the material.

Preferably choose models with adjustable impact plate gap and hydraulic cover opening.

Calculate the replacement cycle and cost of wear-resistant parts.

Investigate equipment operation cases on site or ask the manufacturer to test the machine.

By systematically analyzing the above factors, the impact crusher model suitable for secondary crushing can be efficiently matched to balance efficiency, cost and product quality.