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  • New approach to help turn e-waste into gold

    E waste can be turned into gold-literally.  University of Saskatchewan (U of S) professor Stephen Foley and his team appear to have the Midas touch when it comes to gold extraction research.

    Foley, an associate professor in the Department of Chemistry, along with research associate LoghmanMoradi and PhD student HiwaSalimi, have discovered a new financially viable and environmentally friendly way to recover and recycle gold from electronic waste."We've found a simple, cheap and environmentally benign solution that extracts gold in seconds, and can be recycled and reused," said Foley. "This could change the gold industry."

    Removing gold from cell phone handsets can be challenging. The main issues involve utilizing better ways to protect the environment. 

    Just 41 mobile phones — that’s all it takes to get 1 gram of gold. While this may seem like a mundane fact to the average reader, the significance is clear for those looking to profit from the increasingly lucrative notion of extracting gold from cell phones. The bottom line is that gold can turn up in the most peculiar places, including e-waste, and more and more people are starting to pay attention.

    In fact, mining e-waste could be one of the most profitable directions for electronics recycling to take in the coming years. According to EU Environment Commissioner JanezPotocnik, the business case for extracting gold from cell phones is clear. In July, while addressing various waste issues, the commissioner was quick to highlight the financial benefits of recycling cell phones while pointing out the obvious environmental advantages of recycling in general.

    Indeed a recent UN report  on electronic waste also highlighted the significance of gold extraction.

    According to the report, 1 metric ton of cell phone handsets could yield 340 grams of gold — enough to bring in a sizable profit for anyone with the proper resources for handling large-scale recycling and extracting precious metals from mobile phones.

    What this means is that gold extraction is poised to take the e-cycling world by storm. This makes it even more appropriate to explore the issues and details surrounding gold extraction from cell phones and to take a look at where new innovation will put us in the years ahead.

    The chemicals used in gold extraction from cell phones range from mildly dangerous to extremely hazardous. Most commonly, cyanide is used. In a process called cyanide recovery, cyanide is added to a water base and filtered with zinc dust to aid in the extraction. The method is straightforward but potentially very dangerous, as cyanide is a poisonous toxin.

    What this means is that gold extraction is poised to take the e-cycling world by storm. This makes it even more appropriate to explore the issues and details surrounding gold extraction from cell phones and to take a look at where new innovation will put us in the years ahead.

    The chemicals used in gold extraction from cell phones range from mildly dangerous to extremely hazardous. Most commonly, cyanide is used. In a process called cyanide recovery, cyanide is added to a water base and filtered with zinc dust to aid in the extraction. The method is straightforward but potentially very dangerous, as cyanide is a poisonous toxin.

    The problem with the dexterity of such methods is twofold. First, there is the issue of scale. Profitable gold extraction from cell phones must take place on a large scale, and extracting from more cell phones of course means using more cyanide.

    Disposal is another issue. Once the gold is extracted, dumping the cyanide-water solution should be done with care, but often is not.

    Cyanide is not the only chemical extractor that can be used to recover gold from cell phones. Other toxic chemicals  like nitric acid can also be employed for adequate results, but the environmental concerns are the same. Such chemical methods have created a demand for sustainable alternatives that can effectively address the environmental dangers inherent in gold extraction from cell phones.

    In light of the dangers present, researchers are constantly searching for ways to curtail the potential damage of chemical gold extraction. One of the most interesting of these methods involves the use of fungi  to filter out gold from handsets and other electronics.

    A UK.-based initiative called CLEVER  has produced a phone that boasts replaceable parts and a circuit board capable of dissolving under far less toxic conditions than traditional methods. The CLEVER prototype proposes the use of cellulose bases for cell phone circuit boards that could be dissolved using enzymes to recover gold and other precious metals.

    A simple Google search reveals the increasing popularity of step-by-step guides for gold extraction from cell phones and other electronic devices. Whether those methods are safe or not, the sheer ubiquity of information surrounding this topic is a good indication that we could see more gold recovery in the coming years.

    With government lawmakers and researchers searching for increasingly innovative ways to perfect the process, gold recovery from cell phones could be the next wave of viable and sustainable ways to decrease and eventually eliminate e-waste on a global scale.

    The biggest issue with gold is it is one of the least reactive chemical elements, making it difficult to dissolve. The common practice of mining for gold creates environmental issues because it requires large amounts of sodium cyanide. Recycling gold from electronic scraps like computer chips and circuits involves processes that are costly and have environmental implications.

    The world produces more than 50 million tons of electronic waste per year and 80 per cent of that winds up in landfills.

    What his University of  Saskatchewan research team has discovered is a process using a solution -- acetic acid combined with very small amounts of an oxidant and another acid -- that extracts gold efficiently and effectively without the environmental concerns of current industry practices. In this technique, the gold extraction is done under mild conditions, while the solution dissolves gold at the fastest rate ever recorded.

    Gold is stripped out from circuits in about 10 seconds, leaving the other metals intact. It requires 5,000 litres of aqua regia to extract one kilogram of gold from printed circuit boards, none of which can be recycled. With the new U of S solution, one kilogram of gold can be extracted using only 100 litres of solution, all of which can be recycled over again. The overall cost of this solution is only 50 cents a litre.

    With lower toxicity, cheaper cost and quicker extraction, Foley's team has discovered an approach that could revolutionize the industry and be a veritable gold mine, so to speak.

    The next step for Foley and his team is to move the process into large-scale applications for gold recycling.

    The problem with gold  is that it is one of the least reactive chemical elements, making it difficult to dissolve. That is why artifacts discovered from 3,000 year ago still have gold on them.

    Given this difficulty, there are two main ways to get gold: through mining gold from the earth, which requires massive amounts of sodium cyanide; and recycling  gold from secondary sources like jewelry or electronic scraps.

    Annually, the world produces more than 50 million tons of electronic waste per year. That amount is increasing rapidly due to non-stop innovation that shortens the life span of electronic devices.

    Because of the lack of suitable recycling methods, more than 80 per cent of "e-waste" ends up in landfills, making it a pretty serious environmental issue.

    There are two current industry standards for removing gold from electronic scraps. The first is pyrometallurgy, which burns the gold off using high temperatures. This method is energy intensive, cost prohibitive and releases dangerous gases, like dioxins.

    The second is hydrometallurgy in which leaching chemicals like cyanide solution or aqua regia—Latin for king's water, which is a mixture of concentrated nitric acid and hydrochloric acid—are used, a process Foley called "expensive, very toxic and completely non-recyclable.

    Foley used the city of Guiyu, China, considered the e-waste capital of the world, as an example. Guiyu receives 100,000 tonnes of e-waste per day, and because of unregulated processing, Guiyu has the highest levels of dioxins for any city ever recorded. The result, he continued, is the majority of Guiyu's residents have some form of neurological damage.

    What Foley and his research team discovered is a process that extracts gold efficiently and effectively without any of the downfalls of current industry practices.

    The team uses one of the most mass-produced chemicals: acetic acid. At five per cent concentration it's plain table vinegar. The solution is the greenest solvent next to water, so eliminates the vast number of environmental concerns that come with long standing methods of gold extraction.

    In the current recycling methods, It costs $1,520 to extract one kilogram of gold using aqua regia and results in 5,000 litres of waste. With the U of S solution it costs $66 to produce one kilogram of gold and results in 100 litres of waste that can be reused over again.

    The other main advantage over current recycling processes is that this specific solution is gold selective, meaning it only dissolves gold not other base metals, like copper, nickel, iron and cobalt, found in printed circuit boards.

    The next step for Foley and his team is to move the process into large-scale applications for gold recycling from gold-bearing materials.

    In India, Urooj International is in the business of extraction of gold, silver, palladium, platinum and base metals-copper, lead, zinc, and tin etc. from all types of electronic waste for thirty years.

    To extract three grams of gold from ore, you need one tonne of rock. The company is not yet viable on a big scale like that. To that end they are currently searching for industry partners.

    Electronic recycling industry has very rapidly grown over the years globally since the profit margin is huge. There are countless buyers globally for e-waste, which is an evident proof of the growth and potential of e-scrap recycling trade. A great number of very big scale recyclers are engaged in this industry worldwide.