Metals From Waste, Lessons From the Past to Shape the Future

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Green, Product Developments

Today we would like to introduce Ian Falconer as a guest writer to MetalMiner. Professionally Ian is a mining analyst working in the historic Cornish orefield in the UK, but in his spare time he uses his experience in the extractive industries to try and make sense of the battle over our energy future and how that future will impact mining and metals supply. He shares his ideas on Engage-in-Energy.com.

Until the 1900s, it wasn’t uncommon to see women working in the tin and copper mines of Cornwall. These (Bal Maidens) all but ran the above ground operations taking the ore from the kibbles (ore buckets) and running it through hand sorting and processing, right up to the point of smelting. A combination of legislation, geology, automation and metals prices eventually smothered the Cornish mines, but we should remember that only 100 years ago virtually all hard-rock ores were hand processed everywhere in the world.

I was amazed by the resigned comments of US recyclers that it was simply uneconomic to recycle e-waste in the US and decided to take a look at the state of the art, because as the Bal Maidens demonstrate, time and technology do move on. It turns out that China is publishing scientific paper after scientific paper on industrial scale e-waste reprocessing. Some of the techniques, such as the dis-assembly of printed circuit boards using ultrasound, are already operating at industrial scale. Others, like the use of super-critical methanol or water to boil the components off circuit boards, are still in R&D. But there is a definite and conscious technological effort going on to recover as much of the metal from e-waste as economically possible. Judging by the science, the Chinese are having a great time mining these new deposits and are looking forward to the forecast increase in trade.

And it is potentially a very substantial trade. The figures quoted in the NYT do not do it justice. Using some of the more conservative grades reported in peer-reviewed journals, every year 50 million tons of e-waste could produce as much copper as 19 Bingham Canyons (4.7 million tons) and as much gold as four AngloGold Ashantis (8 million ounces). That’s around $50bn worth of refined metal, just in copper and gold. That is not to mention the millions of ounces of silver, thousands of tons of aluminum, steel, tin, nickel and lead and the possible extraction of some of the more specialist metals like gallium and cobalt. A back of the envelope calculation shows that if you had all the e-waste in one spot and efficient technology to exploit it you could build a company comparable in size to Rio Tinto or BHP Billiton.

When we hear about e-waste it is usually in terms of pollution due to mercury, lead and cadmium that is vented into the environment from small artisanal workshops. What we should also remember is that it is currently economic to have an estimated 700,000 Chinese employed in informal e-waste recycling. Right now there are around 7,000 people employed in the whole recycling sector in the US, similar to the number of Bal Maidens employed in the Cornish mines in the 1850s, and they are all using similar manual techniques. China has started automating e-waste recycling and cleaning up the process as it does so. What is stopping the rest of us?

Maybe we are waiting until we have to start mining our landfills. Its not as far fetched as it sounds. London hosted the first ever landfill mining conference in 2008 (see this link). Any concentration of metals should attract attention as prices rise and landfill was no exception pre-crash. With advances in bacterial leaching, as well as an existing and substantial knowledge-base in both acid and alkali hydro-metallurgy, the only real technical issue holding back in-situ landfill mining is the grade, which in comparison to e-waste is low.

Which provokes the final question; why would you dilute high-grade e-waste with municipal solid waste and make metals recovery more difficult and less profitable in the future? It seems to me that by exporting the raw material we have the e-waste business upside-down and it is waiting for the same kind of revolution that the mini-mills brought for steel.

Ian Falconer

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