Emulsified asphalt equipment is critical for road construction and maintenance, with the colloid mill (its "heart") and production capacity directly determining emulsified asphalt quality (particle size uniformity, stability) and whether it meets construction schedules. Mismatched colloid mill types or capacity cause substandard asphalt (poor aggregate adhesion) and delays/waste. This guide breaks down colloid mill selection and capacity calculation based on project needs, providing a practical framework for enterprises and purchasers.

1. Understand the Colloid Mill: Core of Emulsified Asphalt Quality

The colloid mill shears, grinds, and homogenizes asphalt and emulsified water to form stable emulsified asphalt, influencing particle size (1-5μm for roads) and storage stability (no delamination in 7 days). Clarify its classifications and applicable scenarios first.

(1) Structural Classification: Horizontal vs. Vertical

Horizontal Colloid Mills

Structure: Horizontal rotor/stator; material enters one end, exits the other, with large hopper and stable base.

Advantages: Low vibration (noise ≤ 85dB), easy maintenance (side-disassembled rotor/stator), adapts to high-viscosity asphalt (e.g., SBS-modified, 3000-5000 cP at 135℃).

Applicable Scenarios: Large fixed sites (highway mixing plants), long continuous operation (≥8h/day), high-viscosity asphalt projects. E.g., 4-lane highway (24m width) uses it for 10h continuous production.

Vertical Colloid Mills

Structure: Vertical rotor/stator; material enters top, exits bottom; compact (60% floor area of horizontal mills).

Advantages: Small, lightweight (mobile with frames), low installation demands (no large concrete base), suits low-viscosity asphalt (e.g., AH-70, 1000-2000 cP at 135℃).

Applicable Scenarios: Mobile sites (rural road maintenance, emergency repair), small projects (daily demand ≤50 tons), limited space (narrow urban roads). E.g., rural road (6m width, 10km length) uses trailer-mounted vertical mills for on-site production.

(2) Grinding Precision Classification: Ordinary vs. High-Precision

Ordinary Colloid Mills

Grinding Gap: 0.05-0.2mm; asphalt particle size 3-5μm, storage stability (50℃, 7 days) ≤5% delamination.

Advantages: Low cost (60%-70% of high-precision mills), simple structure.

Applicable Scenarios: General roads (rural, urban secondary) with low durability needs; uses anionic asphalt (PC-2, BC-1) for surface treatment/slurry seal.

High-Precision Colloid Mills

Grinding Gap: 0.01-0.05mm; asphalt particle size 1-3μm, storage stability ≤2% delamination.

Advantages: Uniform particles, strong aggregate adhesion.

Applicable Scenarios: High-grade highways, airport runways (design life ≥15 years); uses cationic asphalt (PC-3, BC-2) for base/micro-surfacing. E.g., airport runways rely on it for water damage prevention.

2. Calculate Production Capacity: Match Schedule and Demand

Production capacity (t/h) ensures on-time construction. Insufficient capacity causes shortages; excess leads to idleness. Calculate based on project scale, construction speed, and unit asphalt consumption.

(1) Determine Project Basic Parameters

Project Scale: Pavement area (length×width), layers, layer thickness.

Asphalt Consumption (per JTG F40-2004):

Slurry seal (3-5mm): 1.8-2.2 kg/m².

Micro-surfacing (5-10mm): 2.5-3.0 kg/m².

Asphalt macadam base (15-20mm): 3.5-4.0 kg/m².

Construction Schedule: Days, daily working hours, hourly construction length.

(2) Calculate Total Demand and Capacity

Example: 2-lane rural road (20km×6m), slurry seal (4mm), 10-day schedule, 8h/day.

Pavement area: 20,000×6=120,000 m².

Total demand: 120,000×2.0=240,000 kg=240 tons.

Daily capacity: 240÷10=24 tons/day.

Hourly capacity (10% redundancy): 24÷8×1.1≈3.3 t/h.

Practical selection: 4 t/h equipment for buffer (e.g., speed increases, maintenance).

(3) Adjust Capacity by Asphalt Type

High-Viscosity Modified Asphalt (SBS): Actual capacity=70%-80% nominal (e.g., 5 t/h nominal=3.5-4.0 t/h actual).

Low-Viscosity Ordinary Asphalt (AH-70): Actual capacity=90%-95% nominal.

Cationic Emulsifiers: Efficiency -5% to -10% vs. anionic.

Confirm "actual capacity" with manufacturers based on asphalt type.

3. Comprehensive Matching: Scenario-Based Selection

Select equipment by integrating colloid mill type, capacity, asphalt type, and environment. Below are three typical scenarios.

(1) Scenario 1: High-Grade Highway Base Construction

Parameters: 6-lane highway (50km×33m), 18mm base, 30-day schedule, 10h/day; SBS-modified cationic PC-3 (3500 cP), 3.8 kg/m².

Capacity Calculation:

Area=50,000×33=1.65M m²; total demand=1.65M×3.8=6270 tons; daily=209 tons; hourly=23 t/h.

Mill Selection: Horizontal high-precision (high viscosity, fixed site, durability); 25 t/h nominal (20-22 t/h actual).

(2) Scenario 2: Rural Road Slurry Seal

Parameters: Rural road (15km×5m), 3mm slurry seal, 5-day schedule, 6h/day; ordinary anionic PC-2 (1500 cP), 1.9 kg/m².

Capacity Calculation:

Area=15,000×5=75,000 m²; total demand=142.5 tons; daily=28.5 tons; hourly=5.2 t/h.

Mill Selection: Mobile vertical ordinary (low viscosity, mobile site); 6 t/h nominal (5.5-5.8 t/h actual).

(3) Scenario 3: Urban Emergency Repair

Parameters: Urban road (500 m²/day pothole repair), 6mm micro-surfacing, 7-day repair; ordinary cationic BC-2 (1200 cP), 2.7 kg/m².

Capacity Calculation:

Daily demand=500×2.7=1.35 tons; hourly (4h/day)=0.37 t/h.

Mill Selection: Ultra-compact mobile vertical; 0.5 t/h nominal.

4. Key Considerations and Mistakes to Avoid

(1) Key Considerations

After-Sales Service: Choose manufacturers with local service (≤24h response) for maintenance (stator/rotor replacement).

Energy & Environment: Check power (10 t/h ≤75kW) and emissions (GB 20891-2014); low noise/zero leakage for sensitive areas.

Auxiliary Compatibility: Ensure matching with storage tanks, mixers (e.g., discharge/feed ports).

(2) Common Mistakes

Blind High Capacity: 10 t/h for 3 t/h needs increases cost 50%-100%.

Ignoring Asphalt Viscosity: Vertical mills for SBS asphalt cause uneven particles.

Overlooking Precision: Ordinary mills for high-grade highways cause delamination (3 days) and reprocessing.

Conclusion: Demand-Oriented Matching

Select emulsified asphalt equipment based on actual needs—colloid mill type matches asphalt/environment, capacity matches schedule/demand. Prioritize "suitability" over "advanced/cheap". Scientific calculation and avoiding mistakes ensure quality, efficiency, and cost savings, supporting road durability and safety.