Metals separation aids effective recycling

With white goods typically consisting of 70% metal, recycling plants in Europe are making use of Eriez Magnetics equipment, tailored to individual needs, to maximise the recovery of these materials.

Each year, the UK alone replaces 2.5 million refrigerators.

Prior to 2002, 40% of these appliances were exported to developing countries and the rest were burnt in incinerators or found their way onto landfill sites.

The majority of these fridges, built prior to 1996, contained harmful ozone depleting substances (ODS).

As a result, from the 1st January 2002, all domestic and industrial refrigeration units within the European Union, containing ODS have to have these chemicals removed prior to scrapping or export.

This new directive, coupled with further legislation set to reduce both the amount of waste going to landfill and its environmental impact, has led to the majority of these appliances being recycled.

Aside from environmental issues, there are major commercial advantages to recycling: namely the recovery of valuable metals such as iron, steel, copper and aluminium.

With white goods, such as fridges, typically consisting of 70% metal, successful recycling plants in Europe are making use of Eriez Magnetics equipment, tailored specifically to their individual needs, to maximise the recovery of these materials.

Once recovered, the metals can be sold back to the metals industries for recycling, to generate revenue.

Doing so not only produces economic benefits, but also environmental.

Recycling metals uses less energy.

For instance, 20 times the amount of energy to produce 1t of recycled aluminium is required to yield 1t of new aluminium.

As a consequence the need to locate and mine new metal ores is reduced, placing less pressure on the environment.

Furthermore, revenue generated by employing an Eriez metal separation system to recover valuable metals, funds the safe disposal of environmentally harmful ODS, greenhouse gases and heavy metals.

Changes in European legislation have will lead to further increases in the percentage of waste being recycled.

The implementation of the Waste Electrical and Electronic Equipment (WEEE) (which includes fridges) and End of Life Vehicles (ELV) directives across Europe, set targets for collection, reuse and recycling, and places the financial responsibility of this waste management with the manufacturers of these products.

As such recycling firms will receive a guaranteed supply of waste, and orders from these manufacturers to subcontract the management of their waste.

A fridge recycling system, supplied by Eriez Magnetics, may incorporate a self-cleaning suspended magnet and two separation modules.

The objective of the suspended self-cleaning magnet being to recover any large, oversized pieces of tramp iron from the process.

Each separation module may typically consist of one or more magnetic drums, vibratory feeders and eddy current separators (ECS).

As the mixed material reaches either drum, the magnetic field attracts and holds the ferrous particles to the drum shell.

As the drum revolves, it carries the material through the stationary magnetic field.

The nonmagnetic material falls freely from the shell, while ferrous particles are held firmly until they are carried out of the magnetic field.

As the mixed material reaches either ECS, eddy currents are induced into all non-ferrous metals passing over, producing a repelling effect.

Every Eriez ECS is constructed with a concentric magnetic rotor, turning at high speeds, within a slower moving non-magnetic shell.

The concentric magnetic rotor allows a maximum magnetic expulsion over the whole area of the outer shell, enabling better separation, especially of small particles.

Low intensity ferrite magnets could be used on both the drum and the ECS in the primary separation module for the recovery of larger pieces of ferrous and nonferrous metals.

High intensity rare earth magnets may then be used in the secondary separation module for the recovery of smaller pieces of ferrous and nonferrous metals.

A carefully adjusted splitter placed after each drum magnet and each ECS allows ferrous and nonferrous metals to be separated from the mixed material.

Tests carried out under controlled conditions for prospective customers have shown that by using this particular setup, 63% of the mixed material, consisting of ferrous and nonferrous metals, can be recovered.

Eriez Magnetics is a world authority in advanced technology for magnetic, vibratory and metal detection applications and designs, develops, manufactures and markets magnetic separation, metal detection and materials feeding, screening, conveying and controlling equipment for process and metalworking industries.

The company provides a state-of-the-art test laboratory enabling customers to have a sample of their material tested, to ensure that the best separation and detection equipment is chosen for a particular application and separation objective.

To ensure optimal quality and productivity of chosen and older equipment, we offer extensive service support with the option of commissioning, calibration and maintenance.

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