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Coal Mill

Specialized grinding equipment for pulverized coal preparation in cement plants and thermal power stations. Safe, reliable, and energy-efficient coal grinding solutions.

<25mmFeed Size
3-40 t/hCapacity
R200=10-20%Fineness
≤15%Max Moisture

Coal Mill in Cement Plant

The coal mill is a critical component in cement manufacturing, responsible for grinding raw coal into fine pulverized coal for injection into the kiln burner and calciner. Efficient coal grinding directly impacts fuel consumption, flame stability, and clinker quality. LIMING coal mills are engineered specifically for the demanding conditions of cement plant fuel preparation.

Our coal mills use hot gas (from the kiln exhaust or auxiliary hot gas generator) to simultaneously dry and transport the pulverized coal. This integrated approach eliminates the need for separate drying equipment and ensures consistent moisture content in the pulverized fuel, which is critical for stable kiln operation and optimal combustion efficiency.

Quick Specifications
Feed Size<25 mm
Capacity3-40 t/h
Product FinenessR200 = 10-20%
Feed Moisture≤15%
Product Moisture≤1%
Hot Gas Temperature200-350°C
Motor Power55-710 kW
Safety StandardATEX/NFPA compliant

Coal Mill Types

Air-Swept Ball Mill

Traditional coal grinding solution with hot air sweeping through the mill to dry and transport pulverized coal simultaneously. Suitable for capacities of 3-25 t/h. Features robust construction with wear-resistant liners and grinding balls. Ideal for coal with moderate moisture content (≤8%). Compact layout with integrated classifier for consistent product fineness.

Vertical Coal Mill

Modern vertical roller mill design optimized for coal grinding with capacities of 15-40 t/h. Handles feed moisture up to 15% with integrated hot gas drying. Lower power consumption (25-30% less than ball mill), smaller footprint, and quieter operation. Equipped with advanced hydraulic roller suspension and automatic wear compensation for consistent performance.

Advantages & Features

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Integrated Drying & Grinding

Hot gas (200-350°C) simultaneously dries and transports coal during grinding. Reduces product moisture to ≤1%, ensuring optimal combustion in the kiln burner.

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Precise Fineness Control

Dynamic classifier with adjustable speed provides precise control of coal fineness. Maintain consistent R200 residue for stable kiln flame and complete combustion.

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Wear-Resistant Design

Heavy-duty manganese steel liners and high-chrome grinding media designed for abrasive coal. Extended service intervals reduce maintenance downtime.

Energy Efficient

Optimized grinding process with efficient classification reduces specific power consumption. Vertical coal mill models achieve 30% energy savings compared to ball mill types.

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Temperature Monitoring

Continuous temperature monitoring at mill inlet, outlet, and bearing housings. Automated alarm and shutdown systems prevent overheating and thermal damage.

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Flexible Fuel Options

Handles anthracite, bituminous coal, lignite, and petcoke. Quick adjustment of classifier speed and grinding pressure enables fast fuel type changes.

Safety Features

Comprehensive safety systems protect personnel and equipment during coal grinding operations

CO Monitoring

Continuous carbon monoxide detection at mill outlet triggers alarms at 50ppm and automatic shutdown at 100ppm.

Explosion Relief Valves

Rupture discs and explosion vents installed at strategic locations safely relieve pressure in the event of a deflagration.

Inert Gas System

N2 or CO2 injection system automatically activates to suppress combustion when CO or temperature thresholds are exceeded.

Temperature Alarms

Multi-point temperature sensors monitor mill inlet, outlet, and bearing temperatures. Automatic shutdown above critical thresholds.

Spark Detection

Infrared spark detectors in pneumatic conveying lines identify and extinguish ignition sources before they reach the dust collector.

Fire Suppression

Automatic water mist or dry chemical fire suppression system integrated with the plant fire alarm network for rapid response.

Technical Specifications

ModelTypeCapacity (t/h)Feed Size (mm)Feed MoistureFineness (R200)Motor (kW)Weight (t)
φ1.7×2.5Air-Swept Ball3-5<25≤10%10-20%5518
φ2.2×3.0Air-Swept Ball5-8<25≤10%10-20%9026
φ2.2×4.4Air-Swept Ball8-12<25≤10%10-20%11035
φ2.4×4.75Air-Swept Ball12-18<25≤10%10-20%16048
φ2.6×5.25Air-Swept Ball18-25<25≤10%10-20%22062
LM130MVertical15-20<25≤15%10-20%20038
LM150MVertical20-28<25≤15%10-20%28052
LM170MVertical25-35<25≤15%10-20%40068
LM190MVertical30-40<25≤15%10-20%56082

Working Principle

  1. Coal Feeding: Raw coal (≤25mm) is fed from the coal storage bin through a weigh feeder into the mill inlet. A rotary air lock prevents false air ingress.
  2. Grinding & Drying: Hot gas (200-350°C) from the kiln or hot gas generator enters the mill simultaneously. In ball mills, rotating steel balls crush the coal; in vertical mills, grinding rollers compress coal against a rotating table.
  3. Pneumatic Transport: The hot gas stream carries ground coal particles upward through the mill body. Initial classification occurs as heavier particles fall back for regrinding.
  4. Classification: A dynamic separator at the mill top classifies particles. Fine coal meeting specification passes through; coarse material returns to the grinding zone via the reject cone.
  5. Product Collection: Pulverized coal is separated from the gas stream in a high-efficiency cyclone and/or bag filter. The clean gas is recirculated or vented after emission control.
  6. Storage & Firing: Pulverized coal is pneumatically conveyed to storage silos, then metered and injected into the kiln burner and calciner through coal dosing and injection systems.

Frequently Asked Questions

What safety features does the coal mill have?
LIMING coal mills include comprehensive safety systems: CO monitoring (alarm at 50ppm, shutdown at 100ppm), multi-point temperature sensors, explosion relief valves, inert gas (N2/CO2) injection systems, spark detection in conveying lines, and automatic fire suppression. All systems comply with ATEX and NFPA safety standards for combustible dust handling.
What is the difference between air-swept and vertical coal mills?
Air-swept ball mills use rotating steel balls in a horizontal cylinder with hot air sweeping through for drying and transport. They are suitable for capacities of 3-25 t/h and coal with ≤10% moisture. Vertical coal mills use rollers on a rotating table, offer higher capacity (15-40 t/h), handle up to 15% moisture, consume 25-30% less power, and require less floor space.
What coal fineness is required for cement kilns?
Cement rotary kilns typically require pulverized coal fineness of 80-90% passing 200 mesh (R200 residue = 10-20%). For calciner firing, slightly coarser coal is acceptable (R90 = 10-15%). LIMING coal mills feature adjustable classifiers to achieve the precise fineness your process requires.

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WhatsApp: +86 153 3380 7511 [email protected]
WhatsApp: +86 153 3380 7511 [email protected]