Researchers Link Feedstock to New Methods for Recycling e-waste

feedstock for e-waste

There’s been a very strong push recently to promote the recycling of electronic waste, which reduces the environmental problems that can result from e-waste ending up in landfills. It’s well documented that the toxins in those electronic devices pose serious hazards to our soil and water.

The process for recycling e-waste is about to get more sophisticated and less expensive, thanks to something not usually associated with electronics manufacturing: feedstock.

It all involves a very hungry bacteria with a passion for sugar. Researchers in Iowa have developed a new biochemical leaching process that uses bacteria to help recover rare earth metals contained within electronic waste. A key ingredient here is the use of corn stover, or the leaves, stalks, and cobs of maize plants left in a field after harvest, and usually amounts to about half the yield of a corn crop.

This development has the potential to reduce the cost of recycling e-waste, which could be a solid boost to an industry that is growing, creating jobs and making a significant contribution to our environment.

How can corn stovers be used to recover metal in electronics?

If the mix of high tech and farm products sounds unique, researchers have been using corn and its byproducts for different high-tech applications for years, including ethanol and bioplastics.

This latest research employs corn stover as a key ingredient to do something else: find a way to extract metals from the fast-growing amount of electronic waste, including the rising amount of cell phones, laptops and old computers being discarded as they get replaced by newer versions. Corn stover, it turns out, could be used to recover metals in these devices so they can be used to manufacture new products.

Corn stover is a biomass feedstock that’s been used to derive fuels like butanol and biodiesel. Researchers have long searched for ways to identify and develop economically, environmentally, and socially sustainable feedstocks for the production of energy.

The e-waste research was directed by the U.S. Department of Energy’s Critical Materials Institute at the Ames Laboratory on the Iowa State University campus. Iowa, by the way, is the world’s biggest corn producer.

The researchers hoped to find ways to make recycling more efficient and less costly, at a time when the amount of discarded electronics is growing at an alarmingly high rate across the globe.

It’s a serious challenge, one that the United Nations has warned about. As the manufacturers continue to develop newer, more advanced versions, the older devices are quickly replaced – and often discarded. That means people are replacing their cell phones or laptops more frequently, adding to the rapid number of electronics being discarded. Without a proper system in each country for recycling e-waste, the environmental hazards are only going to get worse.

Now the Iowa researchers think there may be new and innovative ways to recover high demand rare-earth metals within e-waste. Recycling metals offers big benefits when it comes to preserving our natural resources. Without recycling, we would need to extract metals from virgin ore through mining, a process that uses a considerably higher amount of water and energy. One of the methods used to extract metals from ores is Hydrometallurgy, a liquid chemical process. This is a traditional leaching method used by the mining industry, but less so for recycling, which tends to use sulfuric acid-based methods, and the costly option of heat and pressure.

The researchers looked at ways to create a less costly and more efficient approach for the recycling and recovery methods, and began experimenting with Gluconobacter, a bacteria and acid producing microbe. It contains organic acids that are one of the active ingredients in dissolving and extracting the rare earth metals from waste materials.

They also found that the bacteria are exceedingly hungry, particularly for sweets like glucose and sugar, and thrive when fed sugars. But rather than rely on refined glucose, which is expensive, researchers turned to agricultural waste like corn stover, which could be converted into the basic sugars needed to feed the metal mining bacteria.

They found that corn stover was easy to convert to usable sugars — and much less costly to use when applied to larger scale project uses like recycling.

Are researchers looking at other methods as well?

Ames Laboratory has also been developing a new recycling process that turns old, discarded hard disk drive magnets into new magnet material. As the Ames Laboratory researchers noted, the most pervasive source of valuable rare earth magnets in the growing stream of e-waste is hard disk drives, and they set out to discover ways to get this and other rare-earth elements removed from e-waste during the recycling process.

Their process involves collecting scrapped HDD magnets, removing the protective coatings, and crushing them into powder. Then by depositing the powder on a substrate, researchers could make the properties contained within that powder more customizable for new use.

This is expected to help reduce the amount of manufacturing waste being produced, by making small geometry magnets out of the larger materials.

And this holds out great promise for the e-waste recycling industry. Hard disk drives have a centralized scrap source, and while there are numerous ways to get rare-earth elements out of e-waste, this new application eliminates a number of the processing steps. That allows recyclers to go straight from the discarded magnet to a new one. New magnets for smaller, hand-held electronics can be created and provide a more economical option to consumers.


Today, up to 40 million tons of electronic waste is being generated each year around the world, and e-waste makes up 70 percent of the toxic waste being generated. The toxins in electronics include lead, mercury, arsenic, cadmium, selenium, chromium and flame retardants.

With so many new computers, laptops and cell phones being manufactured every year, there’s a strong need to promote recycling to reduce those environmental risks.

New innovations in e-waste recycling research can help make the process less expensive and more efficient — which in turns makes recycling an even stronger option for coping with e-waste in the future.

In the meantime, it also helps if everyone who owns an unwanted electronics device plays their part by recycling it. Instead of tossing out those products, or letting them sit in a desk, bring them to a top recycling firm like Great Lakes Electronics Corporation, where your devices can be disassembled, and the individual parts can be used to help make new products.

If everyone pitches in and recycling rates can start to rise, the innovations from Ames University can help lower the costs and make recycling an even better option for everyone. Because the only definite way of reversing the challenge that e-waste poses is through recycling and reusing unwanted electronics devices.

Great Lakes Electronics Corporation has years of experience performing environmentally friendly recycling of all electronic products. Their team will disassemble each item into component parts, and the ones that still have value can be sold for reuse. Other parts can be used for metals recovery, and everything is recycled.

In addition, once your material arrives at one of the Great Lakes facilities, it will be inventoried, and all company identification or sensitive information will be removed and destroyed. A Certificate of Recycling will be issued for each shipment.

To learn more, call 888-392-7831 to request a quote.