The production process of limestone crushers follows the flow of "Pretreatment → Graded Crushing → Screening → Finished Product Storage". Combined with limestone's characteristics of low hardness (Mohs hardness 3) and easy crushability, it enables efficient and continuous production. The finished products are widely used in cement, building materials, metallurgy and other fields.

I. Preliminary Preparation: Raw Material Pretreatment

1. Raw Material Testing

Test the moisture content of limestone (must be ≤5%, otherwise it may block the equipment), impurity content (such as clay, quartz sand, etc., which need to be removed in advance if exceeding the standard), and maximum particle size (usually controlled within 500mm; if exceeding, manual crushing is required first).

2. Equipment Inspection

• Check the wear condition of the crusher's liner, hammerheads (for impact crushers) or jaw plates (for jaw crushers), and ensure the gap meets production requirements (general gap for primary crushing is 20-50mm, and 5-15mm for fine crushing).
• Test the transmission system (motor, pulley) and lubrication system to ensure the lubricating oil level is normal and the oil circuit is unobstructed.

II. Core Crushing Process: Graded Crushing to Improve Efficiency

1. Primary Crushing Stage (Mainly Jaw Crushers)

• Function: Crush raw ore (particle size 300-800mm) to 50-150mm, preparing for subsequent fine crushing.
• Working Principle: Through the periodic extrusion of the movable jaw and fixed jaw, limestone is crushed along natural cracks to avoid over-crushing.
• Key Parameters: Processing capacity 10-1000t/h, motor power 30-200kW, crushing ratio 5-8.

2. Secondary/Fine Crushing Stage (Impact Crushers/Cone Crushers)

Impact Crushers (First Choice)

• Applicable Scenarios: Suitable for scenarios requiring high-quality finished product shape (such as construction aggregates), capable of crushing 50-150mm materials to 10-50mm.
• Advantages: Utilizes high-speed rotating hammerheads to impact limestone; the finished product is cubic with needle-flake content ≤8%, and the crushing efficiency is 15%-20% higher than that of cone crushers.

Cone Crushers (Alternative)

• Applicable Scenarios: High-capacity production lines (over 200t/h) or situations where raw materials contain a small amount of hard impurities (such as quartz).
• Advantages: Adopts laminated crushing, resulting in low equipment wear and suitability for continuous high-intensity operations.

3. Sand Making Stage (Impact Sand Making Machine, Configured as Needed)

When it is necessary to produce sand with specifications such as 0-5mm and 5-10mm, the sand making machine is activated to further crush and shape the finely crushed materials.

The "stone-on-stone" mode (mutual impact between materials) is adopted to reduce equipment wear, and the finished product gradation meets the GB/T 14684-2022 standard.

III. Screening and Sorting: Controlling Finished Product Specifications

1. Vibrating Screen Classification

• Equipped with 2-3 layers of screens to separate finished products of different particle sizes (such as 10-20mm, 20-40mm, 40-80mm) according to requirements.
• The undersize material (powder smaller than the smallest screen hole) can be transported to the powder silo via a screw conveyor for use as cement raw meal, etc.

2. Impurity Treatment

• If the raw materials contain metal impurities, a magnetic separator must be used for separation before screening to avoid damaging subsequent equipment.
• When the mud content is relatively high, a sand washing machine can be added for cleaning to reduce the mud content of the finished product to ≤1%.

IV. Finished Product Storage and Conveying

1. Storage System

• Finished products of different specifications are stored in closed silos respectively; a bag filter is installed on the top of the silo to prevent dust overflow.
• A quantitative feeder is installed at the bottom of the silo to facilitate controlling the discharge volume for loading or subsequent processing.

2. Conveying Equipment

• Crushed materials are conveyed by belt conveyors with an inclination angle ≤18° to prevent material sliding; when the conveying distance is long, a tensioning device is added in the middle.
• The belt surface needs to be cleaned regularly to prevent residual materials from mixing into finished products of different specifications.

V. Production Monitoring and Maintenance

1. Real-Time Monitoring

• Monitor the current of each equipment, bearing temperature (≤70℃) and crushing chamber pressure through the PLC control system; automatically alarm and shut down in case of abnormalities.
• Regularly sample and test the particle size of finished products; adjust the crusher gap or screen specifications when the deviation exceeds the limit.

2. Daily Maintenance

• Check the tightness of jaw crusher liner bolts and impact crusher hammerheads every shift; replace the lubricating oil once a week (use 68# hydraulic oil in summer and 46# in winter).
• Calibrate the flatness of the screen every month; replace it in time when the wear exceeds 30% to ensure screening accuracy.

VI. Typical Production Line Configuration Reference

By optimizing the crushing process, the comprehensive energy consumption of the limestone crushing line can be controlled at 8-12kW·h/t, and the qualified rate of finished products reaches over 95%, fully meeting the needs of industrial production.