Waste can be classified according to its physical properties, source, treatment method, and recycling difficulty. Understanding the specific categories of waste helps in selecting appropriate sorting and treatment solutions, improving resource recycling efficiency. The following is a classification system based on sorting technology and treatment characteristics:
I. Classification by Physical Form
Solid Waste: Includes waste metals, plastics, paper, wood, textiles, etc., which can usually be separated by mechanical sorting (such as magnetic separation, air separation, and screening).
Semi-solid/Sludge Waste: Such as sludge, viscous chemical waste, etc., which require pretreatment such as screw conveying and dewatering before sorting or disposal.
Liquid Waste: Includes waste oil, waste solvents, wastewater, etc., which generally have impurities separated through processes such as sedimentation, centrifugation, and filtration.
II. Classification by Sorting Difficulty and Technical Requirements
Easy-to-Sort Waste: Waste with relatively simple composition and regular shape, such as pure PET bottles, OCC cardboard, and unmixed metal waste. Suitable for conventional sorting lines (such as vibrating screens, magnetic separators, and optical sorters).
Medium-difficulty waste to sort: Such as mixed plastics, lightweight composite materials, and waste household appliances containing small amounts of impurities, requiring combined sorting technologies (such as eddy current separation, near-infrared separation, and artificial intelligence visual recognition).
Difficult-to-sort waste: Refers to highly mixed waste with similar physical properties, such as finely crushed mixed waste plastics, electronic waste powder, and textile waste mixtures. Requires advanced technologies (such as hyperspectral imaging and intelligent robot sorting) or pre-treatment (crushing and washing) before sorting.
III. Classification by Recycling Value and Processing Flow
High-value recyclables: Include non-ferrous metals such as copper and aluminum, high-purity plastics, and intact paper products, which can directly enter the recycling process.
Low-value recyclables: Such as mixed plastics, broken glass, and composite packaging materials, requiring fine sorting or downgrading for recycling.
Non-recyclable waste: includes contaminated materials that cannot be washed, thermosetting plastics, asbestos, etc., and generally needs to be sent to energy recovery facilities (such as incineration) or secure landfill.
IV. Classification by Source and Composition Characteristics
Household waste: Originates from households, shopping malls, etc., with complex but somewhat regular composition, commonly a mixture of “dry waste” and “recyclables.” Suitable for integrated processing lines with AI sorting and multi-stage screening.
Industrial waste: Such as scrap steel, waste molds, waste packaging materials, etc., usually with a relatively concentrated composition, but may contain impurities such as oil stains and coatings. Requires a targeted integrated sorting and cleaning solution.
Special waste: Includes electronic waste, scrapped vehicles, medical waste (requiring sterilization and post-treatment), etc., containing hazardous components or special structures, requiring specialized dismantling and sorting equipment (such as enclosed sorting lines, explosion-proof crushers).
V. Classification by Pre-processing Needs Before Sorting
Waste that can be directly sorted: Waste that can enter the sorting line without shredding or washing, such as large cardboard boxes, whole bottles and cans, and regular metal parts.
Waste requiring pre-processing: Waste such as bulky wastes, clumped materials, and sticky, wet waste must first undergo crushing, drying, and loosening before it can be effectively sorted.
VI. Why is an intelligent sorting system needed to handle complex waste?
As waste composition becomes increasingly complex, traditional manual or single-equipment sorting is no longer sufficient to meet high-purity recycling requirements. Intelligent sorting systems, through multi-sensor fusion (vision, near-infrared, laser, etc.) and AI algorithms, can identify waste of different materials, colors, and shapes in real time, achieving millimeter-level precise positioning and sorting. This not only significantly improves the purity of recyclables but also reduces labor costs and accommodates diverse waste sources, making it a core component of modern waste treatment systems.
VII. Recommended Equipment Combinations for Complex Waste Sorting
For complex wastes such as mixed municipal solid waste, electronic waste fragments, and mixed industrial waste, we recommend the following sorting process and equipment combination:
1. Coarse Crushing and Screening Stage
– Dual-shaft shredder machine → Crushes large waste items to a uniform size
– Rotary trommel screen → Separates fine materials (organic matter, dust) and coarse materials according to particle size
2. Mid-stage Intelligent Sorting Stage
– Magnetic separator → Extracts ferrous metals
– Eddy current separator → Separates non-ferrous metals
– AI vision sorter → Identifies and sorts different types of plastics, paper, and composite materials
3. Fine Sorting and Purification Stage
– Near-infrared separator → Further separates mixed plastics (e.g., PET, PE, PP, polymer waste)
– Air separator → Separates lightweight materials (films, foams) according to density
– Vibrating screen and optical sorting combination line → Performs final purification on broken glass, ceramics, etc.
4. Waste Sorting Robot-Assisted Sorting Unit
– Used to handle difficult-to-identify irregularly shaped and hazardous materials, replacing manual sorting for high-risk tasks.
Through the above process, the waste resource recovery rate can be increased to over 85%, producing high-purity recycled materials to meet downstream processing needs.
Guoxin Machinery can provide customized sorting production lines for various waste treatment projects, from design and manufacturing to installation and commissioning, helping customers achieve efficient and intelligent waste resource recovery. Welcome to contact us for solution consultation and equipment quotation: Eve@guoxinmachinery.com.