The management of municipal solid waste (MSW) is a global challenge.

Automated sorting technology, as a key prerequisite for resource recovery, is driving the transformation of waste management from end-of-pipe treatment to a circular economy.

I. Core MSW Sorting Machine and Technical Principles

A modern MSW sorting line is a complex MSW Sorting Machine integrating various physical and sensing technologies. Based on sorting principles, the main technologies can be divided into two categories: direct sorting and indirect identification.

Direct Sorting Technology primarily relies on differences in the physical properties of materials and is suitable for crushed mixed waste.

1. Magnetic Separation: Utilizes differences in magnetic properties to primarily recover ferromagnetic metals (such as iron and steel). Common equipment includes magnetic drums, magnetic head pulleys, and cross-belt magnetic separators.

2. Eddy Current Separation: Generates repulsive forces on non-ferrous metals (such as aluminum and copper), thereby achieving separation.

3. Air/Vibrating Screening: Utilizes differences in density and particle size to separate lightweight plastics and paper from heavy materials. Equipment includes disc screens, air classifiers, and jigs.

4. Indirect Identification and Sorting Technology: Utilizing advanced sensors to identify material composition for precise sorting, this is currently at the forefront of research.

5. Near-Infrared (NIR) Spectroscopic Sorting: By analyzing the spectral fingerprint of materials, the types of plastics, paper, and glass can be accurately identified. For example, advanced optical MSW Sorting Machines can identify up to 1000 materials, with sorting accuracy and speed far exceeding manual methods.

6. X-ray Sorting: Including X-ray transmission and X-ray fluorescence technologies, this can identify the atomic composition of materials, effectively sorting different types of metals, plastics, and composite materials.

7. Laser-Induced Breakdown Spectroscopy (LIBS): By analyzing the plasma emission spectrum generated by materials vaporized by a laser, precise elemental analysis is performed, particularly suitable for distinguishing high-value metals from plastics.

II. Applicable Waste Scope and System Integration

1. Plastics: PET, HDPE, PP, PS, etc.

2. Paper and Cardboard: Old newspapers, old corrugated boxes, etc.

3. Metals: Ferrous metals (iron, steel) and non-ferrous metals (aluminum, copper, zinc). 4. Glass: Colorless and colored glass.

5. Others: Some systems can also process wood, textiles, etc.

A complete waste management strategy includes at least several stages: source separation, collection and transportation, pretreatment, and baler resource utilization.

III. Resource Utilization Pathways for Sorted Materials

1. High-purity metal recovery: Sorted metals can be directly smelted and recycled into new metal raw materials. Through electrochemical leaching and other technologies, copper, lead, zinc, and other metals can be recovered from incinerator slag with purities exceeding 90%, achieving recovery efficiencies of over 80%.

2. High-quality plastic recycling: Sorted single-category plastics can be granulated for manufacturing new plastic products.

3. Pulp and glass recycling: Waste paper can be made into pulp, and waste glass can be directly used as raw material for glass kilns.

4. Energy and chemical conversion

• Organic waste to biogas: Sorted organic waste (OFMSW) can be processed into biogas via anaerobic digestion, which can be used for power generation or purified into natural gas. Studies have shown that co-digestion with sewage sludge can significantly improve gasification efficiency.
• High-calorific-value waste energy conversion: Some difficult-to-recycle plastics, textiles, etc., separated from waste can be converted into energy products such as syngas and bio-oil through advanced thermochemical technologies such as gasification or plasma pyrolysis, significantly reducing the final landfill volume.

5. Solid fuels made from RDF (waste-derived fuel), a combustible material separated from municipal solid(MSW) waste.

IV. Core Advantages of  The MSW Sorting Machine

1. Revolutionary Improvement in Efficiency and Precision
Processing Capacity: Modern optical sorting machines can process up to 8 tons per hour, identifying and sorting material fragments as small as 10 mm.
Sorting Precision: Sensor technology avoids human fatigue and errors, significantly improving sorting purity and laying the foundation for high-quality downstream recycling.

2. Significant Economic Benefits
Reduced Long-Term Costs: Although the initial investment is higher, the automated system can continuously and stably extract high-value resources from waste.

Flexible Adaptability: The system can be customized according to local “waste culture” and composition to maximize the value of resource recovery.

3. Outstanding Environmental and Social Benefits

Promoting a Circular Economy: Converting waste into secondary raw materials reduces the exploitation of primary resources.

Improving the working environment: Freeing workers from dirty and dangerous manual sorting work, allowing them to shift to equipment monitoring and maintenance roles.

Empowering smart management: The system easily integrates with IoT and AI technologies to achieve data-driven intelligent scheduling, process optimization, and full lifecycle management, a core component in building a smart city waste management system.

For MSW sorting machine manufacturers, the key opportunity lies in providing modular, customizable, and intelligent integrated solutions, and deeply participating in the entire value creation chain for customers, from waste collection to resource-based products, jointly driving society towards a “zero-waste future” and a true circular economy.