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End-processing technologies

This section forms part of the main module: Technologies in the Recycling Value Chain.

End-processing technologies

Once WEEE has been pre-processed in various fractions it can:

  • Be disposed in incineration plants or landfills.
  • Be recycled, going through further treatment steps.
  • Be re-used as spare parts.

End-processing step depending on the type of fraction

Recycling technologies

Steel, Aluminium, Copper, Plastics, Glass and Batteries are generally recycled into secondary raw material.

Steel recovery:

Electric arc furnace (EAF)

Steel has to be smelted in furnaces. Electric arc furnaces are used to make steel from waste scrap.

  • Scrap steel is places in the furnace and melted.
  • Limestone and other materials are added to the melted steel to remove impurities.

Copper recovery:

Shalt and ISAMELT furnace

Copper refining flowchart

Plastic recovery:

Plastic recovery machinery

Recycling efficiency

Material recovery efficiency will depend on the efficiency of each step of the chain. Each process of the value chain should be optimized, to achieve best recovery and economic result.

50%

70%

95%

= 33%

Each step of the recycling process should be efficient. Losses (even small) at each step can represent big overall losses and reduce the overall recovery rate of materials. If the collection rate if 50%, the pre-processing recovers 70% of materials and the end-processing recovers 95% of materials, there will be an overall 33% of recycling of materials.

More on recycling efficiency

  • Processes applied in the recycling chain can vary considerably in different regions and countries.
  • OECD countries and developing countries especially have differences.
  • Recycling efficiency between a formal based system and an informal dependant system varies as well
  • Example for gold yield out of printed wiring boards

Improving recycling efficiency

  • Integrating the informal sector and connecting to the global market can bring great advantages.
  • Integrate the informal workers in the collection stage.
  • Train the informal workers in the pre-processing stage.
  • Connect the informal workers in the end-processing stage.

Landfilling technologies

  • Landfills should provide adequate levels of pollution control, especially when dealing with e-waste. This can only be done with significant engineered infrastructure. 
  • Landfilling hazardous materials is a very specialised operation. 
  • In the absence of specific landfills, “transition” technologies may be considered for short-term management. 
  •  

Transitional technologies are:

  • Co-disposal of selected waste with household waste in properly controlled municipal solid waste landfills.
  • Cement waste solidification at landfill site.

Standard secure double lined landfill system

Standard secure hazardous-waste landfill with double leachate collection system

Final landfill

Incineration technologies

  • Incineration is a thermal process.
  • Waste is burnt in the presence of oxygen at very high temperature, normally above 850°C.
  • Incineration produces steam which can be used to generate electricity and heat.
  • Waste that is not burnt remains as solid residue (ash) that need disposal.

There are 4 main types of incineration technologies:

  • Mass Burn Incinerators
  • Modular Incinerators
  • Fluidised Bed Incinerators
  • Refuse Derived Fuel Technologies

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