As a rapidly growing waste stream, e-waste not only demands a solution but also offers numerous opportunities for profit. Through efficient and thorough separation of ferrous and nonferrous metals, precious metals can be recovered and reused, resulting in both economic and environmental benefits.

Savannah Cooper

 

In the past few years, there has been a drastic increase in the production and consumption of electrical and electronic equipment. Added to a decrease in the lifespan of these products, the proliferation of electronics has resulted in massive quantities of waste. Electronic waste, or e-waste, includes computers, cell phones, televisions, printers, calculators and any other electronic or electrical devices. E-waste is the fastest growing waste stream in the world, increasing at a rate of 3 to 5 percent every year.

 

Printed circuit boards from electronics are frequently dumped in landfills or incinerated, releasing toxic gases or leaching hazardous compounds into the surrounding environment. Cathode ray tubes (CRTs) can contain cadmium and more than eight pounds of lead, which can potentially leach out of landfills and contaminate nearby groundwater supplies. In fact, the U.S. Environmental Protection Agency (EPA) classifies CRTs as hazardous waste and regulates their disposal. Mercury, sulfur, cadmium, lead, americium and many other hazardous materials exist in e-waste, requiring the material to be properly and carefully disposed of.

 

These electronic components often contain high amounts of precious metals, such as copper, gold, silver and palladium. Extracting these precious metals from circuit boards is not only profitable; it is also beneficial for the environment. Because most e-waste contains precious and base metals, this waste stream is a potentially important secondary source of both ferrous and non-ferrous metals.

 

Economic Value

Although most of electronic waste’s weight comes from plastics and steel, precious metals offer recyclers the most economic value. It is far more economical to recover gold from electronic waste than to mine gold from naturally occurring mineral ore. The separation of e-waste also offers recyclers the chance for a high return on investment through the sale of recovered tin, silver, gold, copper, lead and palladium to smelters. Even the plastics can go on to be recycled and reused, along with other, less valuable materials found in e-waste.

 

The hazardous compounds in e-waste can have a negative impact on the environment. The toxic chemicals often end up in groundwater, soil and air, and thus eventually in land and sea animals, in crops and in drinking water supplies. However, reusing these metals diminishes the demand for new products and decreases the use of limited raw materials. Recycling e-waste also frees up landfill space, reducing the amount of pollution in the environment. Through metal separation and reuse, the amount of greenhouse gas emissions are also reduced, slowing down the impact of climate change.

 

The world generates an estimated 50 million tons of e-waste each year, and the U.S. is the largest producer of e-waste, generating 3 million tons. The U.S. alone discards 30 million computers every year, and Europe throws out 100 million mobile phones. A United Nations study predicts that e-waste from mobile phones in India will be 18 times higher in 2020 than it was in 2007, and electronic waste from old computers in South Africa and China will rise 200 to 400 percent over the same period.

 

Unfortunately, when electronics are landfilled, their value is lost. Nearly $70 billion worth of precious metals were discarded in 2010. Currently, recyclers recover more than 100 million pounds of materials from electronics each year, and much more could be recovered with the proper metal separation techniques.

 

Proper Separation

The separation of metals from non-metals in a waste stream creates the necessary conditions for further processing. Physical separation techniques are safe and eco-friendly but also extremely energy-intensive. With a metal separation system, you can recover valuable materials and precious metals efficiently. The system begins with shredding of the material. Once the material is shredded, it travels by a conveyor to a trommel screen. The trommel establishes a common-sized material, sorting out the pieces by size. This separation is important as the eddy current separator farther downstream requires materials of a similar size to perform a clean separation. The trommel screen permits shredded material less than 1.5” to move downstream. Larger material is removed from the stream and put through the shredder again.

 

The fines in the material stream are then transported by another incline conveyor to a drum magnet, which removes ferrous metals from the stream. The remaining material then goes through a separator that pulls out non-ferrous metals (e.g. aluminum) from the waste stream. The remaining shredded e-waste travels up one last conveyor to a metal recovery system.

 

Metal separation allows operators to extract additional value from electronic waste and automotive shredder residue. As a rapidly growing waste stream, e-waste not only demands a solution but also offers numerous opportunities for profit. Through efficient and thorough separation of ferrous and nonferrous metals, precious metals can be recovered and reused, resulting in both economic and environmental benefits.

 

Savannah Cooper is the writer at Worldwide Recycling Equipment Sales, LLC (Moberly, MO). She received her bachelor’s in English–Creative Writing from Lincoln University. Savannah can be reached at [email protected].

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