Electronic Waste Sorting Technology and Resource Utilization

With the rapid development of the information age, the replacement cycle of electronic and electrical equipment (EEE) has shortened dramatically, leading to an explosive growth in global electronic waste (WEEE).

I. Introduction to Electronic Waste

electronic waste

Electronic waste(E-Waste) refers broadly to discarded and no longer used electronic and electrical equipment. It covers a wide range, from small items like mobile phones, USB drives, and remote controls to large items like refrigerators, air conditioners, and televisions.

Main Categories:

1. Large Household Appliances: Refrigerators, washing machines, air conditioners, etc.

2. Small Household Appliances: Microwave ovens, vacuum cleaners, rice cookers, etc.

3. IT and Communication Equipment: Computers, servers, mobile phones, printers, etc.

4. Consumer Electronics: Televisions, stereos, cameras, etc.

5. Lighting Equipment: Fluorescent lamps, LED lights, etc.

6. Power Tools: Electric drills, electric saws, etc.

The Two Sides of E-waste:

Benefits: Rich in valuable metals such as gold, silver, palladium, copper, and aluminum, as well as high-value plastics and glass. One ton of discarded mobile phones contains far more gold than one ton of gold ore.

Disadvantages: Contains toxic and harmful substances such as lead, mercury, cadmium, and brominated flame retardants. If improperly disposed of, these substances can seep into soil and groundwater or release highly toxic gases such as dioxins through incineration, posing a serious threat to the ecological environment and human health.

II. Impacts of Improper Electronic Waste Disposal

1. Environmental Pollution: Heavy metals and persistent organic pollutants (POPs) can cause long-term, difficult-to-remediate heavy metal pollution in soil and water.

2. Resource Waste: Landfilling or incinerating precious non-renewable mineral resources is a huge waste of Earth’s resources.

3. Health Hazards: Direct contact or bioaccumulation through the food chain can lead to various diseases such as nervous system damage, cancer, and endocrine disorders. 4. Data Security Risks: Incomplete destruction of storage devices may lead to the leakage of personal privacy, trade secrets, and even national secrets.

III. Electronic Waste Sorting Process

The purpose of sorting is to break down mixed electronic waste into single or similar materials, laying the foundation for subsequent deep recycling and reuse.

Processes and Technologies:

1. Pre-processing and Dismantling
· Manual Pre-sorting: Initially separating different categories (e.g., televisions, refrigerators, computers).
· Manual Dismantling: Removing components containing hazardous substances (e.g., batteries, capacitors, mercury-containing backlight panels, refrigerants) and high-value components (e.g., memory modules, CPUs).
· Crushing and Grinding: Using equipment such as dual-shaft shredders and hammer crushers, the entire machine is crushed into small pieces, achieving initial separation of components such as metals, plastics, and circuit boards.

2. Automated Sorting Technology
· Magnetic Separation: Utilizing high-intensity magnetic separators to efficiently separate ferromagnetic metals (e.g., iron, steel).

· Eddy current separation: Highly efficient for separating non-ferrous metals (such as aluminum, copper, and brass), particularly suitable for recovering aluminum from mixed scrap.

· Wind(trommel screen )separation: Separates lightweight plastics and rubbers from heavy metals by utilizing differences in material density and aerodynamic properties.

· Electrostatic separation: Precisely separates different types of non-ferrous metals and plastics by utilizing differences in material conductivity, especially suitable for separating copper from plastics in complex circuit board scrap.

· Near-infrared (NIR) spectral separation: Achieves high-speed, high-precision separation of different types of plastics (such as ABS, PS, PP, and PC) by identifying the molecular vibrational spectra on the material surface, greatly improving the purity and value of recycled plastics.

· X-ray fluorescence (XRF) separation: Identifies the type and content of elements, and can be used to separate different alloys or precisely remove plastics containing brominated flame retardants from waste.

· Visual Recognition and Robotic Sorting: Combining artificial intelligence (AI) and deep learning algorithms, high-definition cameras identify specific components (such as circuit boards and batteries of specific models), which are then precisely grasped by industrial robots, achieving intelligent and flexible sorting.

IV. Post-Sorting Processing and Value Utilization

1. Metals:

Precious Metals (Gold, Silver, Palladium): Through metallurgical refining (such as pyrometallurgy and hydrometallurgy), precious metals with a purity of up to 99.99% are recovered and reused in the electronics, jewelry, and other industries.

Base Metals (Copper, Aluminum, Tin): As high-quality recycled raw materials, they are directly smelted into metal ingots or alloys for the manufacture of new wires, profiles, and components.

2. Plastics:

After cleaning and granulation, depending on the grade, they can be used to manufacture new electronic product casings, park benches, building material templates, etc.

3. Glass:

CRT Picture Tube Glass: Requires special processing; lead glass can be recycled for new CRT manufacturing or lead smelting.

LCD Panel Glass: After processing, it can be used in the building materials or ceramics industries.

4. Hazardous Materials:

They are safely transported to qualified hazardous waste treatment centers for harmless disposal, such as high-temperature incineration or secure landfill.

Electronic waste presents both challenges and opportunities. Investing in and constructing a technologically advanced and rationally configured automated electronic waste sorting line is not only a requirement for fulfilling environmental responsibilities but also a highly economically viable strategic move.

Guoxin Machinery is committed to providing customers with comprehensive services, from process design and core equipment manufacturing to complete line integration and operation and maintenance.