Beijing Tongzhou District Construction & Decoration Waste Recycling Project

Beijing Tongzhou District Construction & Decoration Waste Recycling Project

I. Project Background

Due to rapid urban renewal in Beijing's sub-center (Tongzhou District), large amounts of construction and demolition (C&D) waste and decoration waste are generated annually. The previous disposal method (mixed transport + simple landfilling) resulted in low resource utilization (<30%), high transport costs, dust/noise complaints, and unstable recycled product quality. To support the "Circular Economy Demonstration" policy, this project was initiated to establish an efficient recycling system for both C&D and decoration waste.

II. Technical Parameters and Configuration

The system adopts a "two-stage crushing + three-stage screening + multi-stage sorting (magnetic + air + optical + manual)" process.

Parameter Value

Site Area 31,473.6 m²

Total Investment ~85 million RMB

Annual Capacity 400 kt (300 kt C&D waste + 100 kt decoration waste)

Annual Output Aggregates: 0-5mm (120 kt), 5-10mm (100 kt), 10-20mm (80 kt); Cement-stabilized macadam: 150 kt; Masonry mortar: 50 kt

Key Equipment:

Feeders: Heavy bar vibratory feeder with pre-screening (≤600 mm feed)

Crushers:Jaw crusher (coarse) + impact crusher (fine); output ≤31.5 mm

Screens: 2/3-layer circular vibrating screens (5/10/20 mm meshes)

Sorting: Magnetic separator + air separator + NIR optical sorter + manual sorting platform

Dust Control: Enclosed building + pulse bag filter (emission ≤10 mg/m³) + dry fog system

Mobile Lines (2 units): Crawler mobile crusher/screener (80 t/h each) for on-site use

Control System: PLC central control + industrial IoT (remote monitoring, fault alarm, auto data reporting)

Safety & Environmental Devices:

Belt emergency pull cords (≤30 m spacing)

Overload protection (crusher, magnetic separator)

Differential pressure alarm (dust filter)

Sound enclosure + acoustic panels (daytime noise ≤65 dB(A) at boundary)

III. Implementation Plan

3.1 Foundation and Mechanical Installation

Steel structure main workshop (approx. 12,000 m²)

Concrete foundations with vibration isolators for crushers/screens

Installation precision: jaw crusher spindle horizontal error ≤0.15 mm/m; belt centerline deviation ≤5 mm

3.2 Electrical and Control System Commissioning

Shielded cables + fiber optic ring network

PLC programming: setting crusher gap, screen amplitude, air separator speed

Safety interlock test: response time ≤1 second (overload, blockage, high filter pressure)

ERP integration for automatic production reporting

3.3 Trial Operation and Optimization

No-load test: 4 hours continuous; bearing temp rise ≤45°C; vibration ≤4.5 mm/s

Load test: Gradual loading 25% → 50% → 75% → 100%

Test C&D line and decoration waste line separately

Monitor: feeder/crusher current, screening efficiency (≥85%), air separator efficiency (≥90% for decoration waste)

Target product impurity rate ≤0.8%; adjust sorter parameters accordingly

Final aggregates meet JGJ/T 240 standard

IV. Results

4.1 Resource Utilization

Resource utilization rate increased from <30% to 91%

Annual aggregate output: ~300 kt (used in cement-stabilized macadam, masonry mortar, and external sales)

Natural sand/gravel saved: ~280 kt/year

4.2 Environmental and Safety Performance

Fugitive dust ≤0.5 mg/m³ (meets Beijing strict standards)

Light material removal rate (plastic, wood, etc.) ≥90%; final impurity ≤0.6%

Zero environmental penalties or major accidents since commissioning

Safety devices triggered successfully 10+ times (belt tear, filter pressure high, etc.)

4.3 Economic Benefits

Metric Value

Unit energy consumption ≤6.0 kWh/ton

Annual revenue (disposal fees + product sales) ~52 million RMB

Annual operating cost (power, labor, maintenance, etc.) ~33 million RMB

Annual net profit ~12 million RMB

Payback period ~7 years (or ~5 years with government subsidies)

Additional benefits:

Created ~40 local jobs

Reduced waste transport trips by ~15,000 per year, easing traffic and road dust

Conclusion: 

This project demonstrates that a "two-stage crushing + three-stage screening + multi-stage sorting" system with PLC control and robust environmental/safety features can effectively recycle mixed C&D and decoration waste at high efficiency. It provides a replicable model for large cities undergoing urban renewal.