E-Waste And Waste Oil Combine To Make Silver

As the saying goes, “if it can’t be grown, it has to be mined”– but what about all the metals that have already been wrested from the bosom of the Earth? Once used, they can be recycled– or as this paper charmingly puts it, become ore for “urban mining” techniques. The technique under discussion in the Chemical Engineering Journal is one that extracts metallic silver from e-waste using fatty acids and hydrogen peroxide.

This “graphical abstract” gives the rough idea.

Right now, recycling makes up about 17% of the global silver supply. As rich sources of ore dry up, and the world moves to more sustainable footing, that number can only go up. Recycling e-waste already happens, of course, but in messy, dangerous processes that are generally banned in the developed world. (Like open burning, of plastic, gross.)

This paper describes a “green” process that even the most fervant granola-munching NIMBY wouldn’t mind have in their neighborhood: hot fatty acids (AKA oil) are used as an organic solvent to dissolve metals from PCB and wire. The paper mentions sourcing the solvent from waste sunflower, safflower or canola oil. As you might imagine, most metals, silver included, are not terribly soluble in sunflower oil, but a little refining and the addition of 30% hydrogen peroxide changes that equation.

More than just Ag is picked up in this process, but the oils do select for silver over other metals. The paper presents a way to then selectively precipitate out the silver as silver oleate using ethanol and flourescent light. The oleate compound can then be easily washed and burnt to produce pure silver.

The authors of the paper take the time to demonstrate the process on a silver-plated keyboard connector, so there is proof of concept on real e-waste. Selecting for silver means leaving behind gold, however, so we’re not sure how the economics of this method will stack up.

Of course, when Hackaday talks about recycling e-waste, it’s usually more on the “reuse” part of “reduce, reuse, recycle”.  After all, one man’s e-waste is another man’s parts bin–or priceless historical artifact.

Thanks to [Brian] for the tip.Your tips can be easily recycled into Hackaday posts through an environmentally-friendly process via our tipsline. 

Gold Recovery From E-Waste With Food-Waste Amyloid Aerogels

A big part of the recycling of electronic equipment is the recovery of metals such as gold. Usually the printed circuit boards and other components are shredded, sorted, and then separated. But efficiently filtering out specific metals remains tricky and adds to the cost of recycling. A possible way to optimize the recovery of precious metals like gold could be through the use of aerogels composed out of protein amyloids to which one type of metal would preferentially adsorb. According to a recent research article in Advanced Materials by [Mohammad Peydayesh] and colleagues, such aerogels could be created from protein waste from the food industry.

The adsorption mechanism of the protein amyloids is a feature of these proteins which form chelants, which are structures that can effectively bond to metal ions. These are usually organic compounds, and are used in certain medical treatments where heavy metal poisoning is involved (chelation therapy). By having these protein amyloids in an aerogel structure, the surface area for adsorption is maximized, which in the research article is said to have an efficiency of 93.3% for gold recovery, while leaving the other metals in the aqua regia solution (nitric and hydrochloric acid) mostly untouched.

Of note here is that although the food waste protein angle is taken, the experiment used whey protein. This is also one of the most popular food supplements in the world, to the point that microbial production of whey is a thing now. Although this doesn’t invalidate the aerogel chelation approach to e-waste recycling, it’s a curious omission in the article that does not appear to be addressed.

Making The Commodore SX-64 Mini

When you find a portable TV from the 1980s, and it reminds you of the portable Commodore 64, there’s only one thing to be done. [Aaron Newcomb] brings us the story of taking an Emerson PC-6 and mating it to the guts of his THEC64 Mini. It’s a bit of a journey, as the process includes modding the TV to include a composite input and trimming some unused PCB off the TV’s mainboard. Then some USB ports and a three-and-a-half inch floppy drive were shoehorned into the chassis, with the rear battery compartment holding the parts from THEC64 Mini.

The build was not entirely without issue. It turns out the degaussing coil connector can plug perfectly into the service port, and Murphy’s law proved itself true again. But no harm was done, and the error was quickly discovered. All that was left was to button the chassis back up and add some paint and 3d-printed trim details. The build looks great! Come back after the break to watch the video from the [Retro Hack Shack] for yourself.

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Virtual Mini Pinball Cabinet Scores Big

Do you love pinball, but can’t justify owning a full-size cabinet? Yeah, us either, and that’s why we’re so interested in [mircemk]’s great-looking DIY mini virtual pinball cabinet. Since [mircemk] is a IT service specialist, they are lucky enough to have access to lots used and broken equipment, and that’s what this build is made of.

Essentially two computers working together, the playfield is a old 17-inch monitor that needed its LED lighting replaced before gracing the MDF cabinet The backglass is an ancient 10-inch tablet that was perfect for this application.

Even the motherboard, RAM, and SSD came from one of [mircemk]’s previous PCs. The SSD needed some attention first as well — it didn’t work sometimes, and didn’t show up in the BIOS at all, so [mircemk] threw it in the oven for 10 minutes at 250°, and now all is well.

One thing we really like about this build is that instead of designing a control board for the buttons, [mircemk] used a cheap USB joystick and wired them up to the pads.

So how does the tablet figure into all of this? It’s connected to a PC via USB and does its job thanks to a piece of software called Wired XDisplay. There is even a tilt switch in this bad boy. Because what’s a pinball cabinet without a tilt switch? A cheater’s cabinet, that’s what. Check out the build/demo video after the break.

Don’t even have the space for a mini cabinet? We hear you. Here’s one that fits in the palm of your hand.

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PCB-Filled Dream Desk Will Only Get Cooler With Age

We all have one. Maybe you’re sitting at it now, or just wishing you were — that perfect desk. You know the one — a place for everything and everything in its place, ample acreage, specialized storage, and top-notch looks. Oh, and blinkenlights. Can’t forget those.

It took four months of hard work, but [Build XYZ]’s dream desk has been finely fabricated into fruition. There’s a lot to unpack with this build, which you can appreciate after the break, but it all started with a donated up/down desk from Progressive Desk. After building the base and putting it through its body weight-driven paces, [Build XYZ] set about making the perfect top, which, as you can see, highlights an assortment of PCBs by encasing them for eternity in resin.

But don’t let your admiration stop there, because the woodworking is just as much a part of the show. In addition to the functional blinkenlights that notify [BuildXYZ] when it’s time to stop working for the day or just take a break, there’s a working wireless charger hiding among the FR4. We can’t wait to look back on this desk in 20 years or so and we also can’t wait to see how PCBs will change over the next 20 years.

This tightly-produced video is a fascinating look into the process of forever immortalizing things in resin. So much resin, in fact, that [Build XYZ] came up a gallon short during the pour and had to wait an excruciatingly long time before more resin showed up. Seeing as how you totally can’t tell at all in the final build, we have maximum respect for [Build XYZ]’s inclusion of this part in the first place, which serves as a warning to the rest of us.

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There’s Gold In That There Graphene

There’s gold all around us, embedded in our electronics. There are people who collect e-waste and use various methods to extract gold from them. However, it is hard to qualify it as a “get rich quick” scheme because the amount of gold recovered is usually minute. Still, if you can do volume, you can make some money and recycling is always a good idea. At the University of Manchester, they have a better way to extract gold from e-waste using graphene. You can see a brief video about the process below, or read the full paper.

The process is relatively simple. You dissolve the e-waste in a solvent, add some graphene oxide, and the gold appears bound to the graphene. You pull out the graphene and burn it off to result in the gold you want. A gram of graphene can grab 2 grams of gold and graphene is relatively cheap per gram compared to gold.

Graphene oxide nanosheets are processed using ascorbic acid into a colloid suspension. The chemical process converts gold bound with chlorine into elemental gold. After diving into why the process works, they were able to increase the selectivity of the process by manipulating the pH so that the majority of the residue is actually gold.

The team believes they can build a continuous process that takes liquefied e-waste and extracts gold as it flows through the system. If you’d rather go with the traditional method, here’s a start for you. Then again, there are other metals to recover besides gold.

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A vape pen, broken into parts, all laid out on a cutting mat

2022 Hackaday Prize: Disposable Vape Pens Turned Project Parts

Disposable vape pens, a sub-genre of electronic cigarettes, have been a fad for a few years now – they’re small self-contained devices with a rechargeable battery and some vape liquid inside. As the battery discharges and the liquid runs out, the entire vape pen is typically thrown out. [Dimitar] wants to change that, however, and teaches us how to reuse as much of the vape pen as possible — as yet another underappreciated source for parts we can use in our projects.

In an extensive worklog, he breaks down and documents a vape pen’s inner workings, coupled with a video we’ve placed below the break showing ways to disassemble them. In these, he shows how we can reuse the casing and the plastic parts, should any of us be interested in a project that happens to fit the e-cig form factor. Attention is paid to the sensor that triggers the evaporation — it may look like a microphone, but is actually a purpose-built pressure-sensor with a high-side switch! He tears into one of these in a separate video, showing how to reuse it as a capacitive touch controller. He also aiming to assemble a small database of related resources on GitHub, currently, hosting the files for the protection circuit he developed as part of his recommendations for safely reusing vape pen Li-ion batteries.

[Dimitar]’s journey is ongoing, and we can’t wait to see some fun uses for these components that he will certainly stumble upon on his way! For instance, here’s a hacker using an e-cig battery to power a pair of RGB LED-adorned sunglasses, replacing the AAAA battery they originally came with. We’ve seen hackers make guides on reusing each and every part of microwave ovens, printers and laptops, and we ourselves have talked about reusing ATX power supplies and computer mice.

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