With the acceleration of urbanization and the increasing scarcity of land resources, ecological governance and resource utilization of landfills have become key issues for sustainable urban development. As the main target of treatment, the disposal of stale waste is a complex system engineering that integrates environmental engineering, mechanical sorting, and resource recycling. The disposal of stale waste is a systematic project that integrates environmental governance, resource recycling, and land regeneration. Its core goal is to efficiently separate stabilized waste that has been buried for many years under the premise of safety and environmental protection, and achieve maximum resource utilization.
Definition and Main Components of Stale Waste
Stale waste, specifically referring to municipal solid waste that has reached a relatively stable state after long-term (usually 8-10 years or more) anaerobic degradation and physicochemical reactions in landfills. Its original organic components (kitchen waste, paper, wood, etc.) have been extensively decomposed and converted into humus and biogas. The final stabilized products mainly include:
- Humus soil: accounts for the highest proportion, usually up to 40% -60%, and is the final product of waste biodegradation. It has a high organic matter content but may be enriched in salt and heavy metals.
- Inert substances: such as bricks, rubble, ceramics, glass, etc., accounting for about 20% -35%, with stable physical and chemical properties.
- Difficult to degrade substances: mainly various plastics (especially film plastics), rubber, and textiles, accounting for about 10% -25%, are the focus of resource recycling.
- Metals: mainly iron metals, accounting for about 1% -5%, have high recycling value.
Significance of Stale Waste Recycling
Due to the above mentioned, recycling stale waste is an urban environmental governance action with multiple strategic significance:
Release Land Resources and Eliminate Environmental Risks
Release valuable occupied land for urban development or ecological construction; Simultaneously addressing long-term environmental hazards such as leachate pollution of groundwater and disorderly discharge of landfill gas in old landfills.
Realize Waste Utilization and Promote Circular Economy
By classifying, recycling, and utilizing inert materials, metals, plastics, and humus, waste can be converted into renewable resources, reducing the exploitation of primary resources.
Core Stale Waste Recycling Equipment
GEP ECOTECH has been following the needs of the market and customers, committed to creating a "smarter, more refined, and cleaner" process for the disposal of stale waste. In GEP ECOTECH's solution, the selection of equipment models and parameter settings (such as screen size sequence, wind speed, magnetic field strength) will be finely designed and dynamically adjusted based on the specific composition characteristics of stale waste to form the optimal process combination. Here are the core stale waste recycling equipment:
Double-Shaft Shredder
A crucial pre-treatment unit for size reduction and homogenization. It utilizes two counter-rotating shafts equipped with interlocking cutters to shear, tear, and shred large, agglomerated waste clumps. This effectively breaks down compacted stale waste, loosens entangled materials, and reduces particle size, preparing the mixture for efficient subsequent separation by downstream equipment like trommel screens and wind sifters. Its robust design and low-speed, high-torque operation ensure reliable handling of tough and abrasive materials such as plastics, textiles, and wood residues.
Trommel Screen
The core equipment for particle size classification. Waste rolls forward in a tilted rotating screen, and materials smaller than the screen hole size (mainly humus soil and small plastics) are separated through the screen, while over-sized materials (bricks, large plastics) are discharged forward along the screen hole. Multiple combinations of screen with different aperture sizes are often used to achieve multi-stage screening.
Wind Sifter
A key equipment for separating light and heavy materials based on aerodynamic principles. After shredding and screening, the materials are collected in a controllable airflow field, with lightweight plastics, paper, and other materials carried away by the airflow, while heavier humus soil, stones, and other materials fall nearby. This is one of the most effective methods for extracting high calorific value combustibles from mixed waste. The wind sifter can accurately control the wind speed and pressure to meet the separation requirements of materials with different humidity and specific gravity, achieving the best sorting effect.
Magnetic Separator
Equipment specifically designed for recycling ferrous metals. High strength permanent magnets or electromagnetic rollers are usually used. When the material passes by, the ferromagnetic material is firmly adsorbed on the surface of the roller and automatically falls off and collected as the roller rotates to the non-magnetic area. The device has mature technology, high recycling efficiency (usually>95%), and significant economic value. Magnetic separators are often placed at key points after crushing and combustible material separation for multi-stage recovery.
Besides, GEP ECOTECH is also able to equip the entire stale waste recycling line with complete enclosed factories, negative pressure dust removal, spray deodorization, leachate drainage and other environmental protection facilities, truly achieving the strategic goal of "turning waste into treasure and being environmentally friendly", and transforming the past environmental burden into a sustainable resource. If you have any inquiries on the stale waste recycling, please feel free to contact us.
