Bipolar Uranium Extraction From Seawater With Ultra-Low Cell Voltage

June 11, 2025 by Maya Posch 52 Comments

As common as uranium is in the ground around us, the world’s oceans contain a thousand times more uranium (~4.5 billion tons) than can be mined today. This makes extracting uranium as well as other resources from seawater a very interesting proposition, albeit it one that requires finding a technological solution to not only filter out these highly diluted substances, but also do so in a way that’s economically viable. Now it seems that Chinese researchers have recently come tantalizingly close to achieving this goal.

The anode chemical reaction to extract uranium. (Credit: Wang et al., Nature Sustainability, 2025)

The used electrochemical method is described in the paper (gift link) by [Yanjing Wang] et al., as published in Nature Sustainability. The claimed recovery cost of up to 100% of the uranium in the seawater is approximately $83/kilogram, which would be much cheaper than previous methods and is within striking distance of current uranium spot prices at about $70 – 85.

Of course, the challenge is to scale up this lab-sized prototype into something more industrial-sized. What’s interesting about this low-voltage method is that the conversion of uranium oxide ions to solid uranium oxides occurs at both the anode and cathode unlike with previous electrochemical methods. The copper anode becomes part of the electrochemical process, with UO₂ deposited on the cathode and U₃O₈ on the anode.

Among the reported performance statistics of this prototype are the ability to extract UO₂²⁺ ions from an NaCl solution at concentrations ranging from 1 – 50 ppm. At 20 ppm and in the presence of Cl^– ions (as is typical in seawater), the extraction rate was about 100%, compared to ~9.1% for the adsorption method. All of this required only a cell voltage of 0.6 V with 50 mA current, while being highly uranium-selective. Copper pollution of the water is also prevented, as the dissolved copper from the anode was found on the cathode after testing.

The process was tested on actual seawater (East & South China Sea), with ten hours of operation resulting in a recovery rate of 100% and 85.3% respectively. With potential electrode optimizations suggested by the authors, this extraction method might prove to be a viable way to not only recover uranium from seawater, but also at uranium mining facilities and more.

Threaded Insert Press Is 100% 3D Printed

June 11, 2025 by Tyler August 12 Comments

Sometimes, when making a 3D printed object, plastic just isn’t enough. Probably the most common addition to our prints is the ubiquitous brass threaded inset, which has proven its worth time and again over the years in providing a secure screw attachment point with less hassle than a captive nut. Of course to insert these bits of machined brass, you need to press them in, and unless you’ve got a very good hand with a soldering iron it’s usually a good idea to use a press of some sort. [TimNummy] shows us that, ironically enough, making such a press is perfectly doable using only printed parts. Well, save for the soldering iron, of course.

He calls it the Superserter. Not only is it 100% printed plastic, but the entire design fits on a single 256 mm by 256 mm bed. In his case it was done on the Bambulab X1C, but it’s a common enough print bed size and can be printed without any supports. It’s even sized to fit the popular Gridfinity standard for a neat and tidy desk and handy bin placement for the inserts.

[TimNummy] clearly spent some time thinking about design for 3D printed manufacturing in order to create an assembly that does not need linear rails, sliders, or bearings as other press projects often do. The ironic thing is that if that same amount of effort went into other designs, it might eliminate the need for threaded inserts entirely.

If you haven’t delved into the world of threaded inserts, we put up a how-to-guide a few years ago. If you’re wondering if you can get away with just printing threads, the answer is “maybe”– we highlighted a video comparing printed threads with different inserts a while back to get you started thinking about the design limitations there.

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Back To The Future Lunchbox Cyberdeck

June 10, 2025 by John Elliot V 4 Comments

Our hacker [Valve Child] wrote in to let us know about his Back to the Future lunchbox cyberdeck.

Great Scott! This is so awesome. We’re not sure what we should say, or where we should begin. A lot of you wouldn’t have been there, on July 3rd, 1985, nearly forty years ago. But we were there. Oh yes, we were there. On that day the movie Back to the Future was released, along with the hit song from its soundtrack: Huey Lewis & The News – The Power Of Love.

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What Marie Curie Left Behind

June 10, 2025 by Al Williams 25 Comments

It is a good bet that if most scientists and engineers were honest, they would most like to leave something behind that future generations would remember. While Marie Curie met that standard — she was the first woman to win the Nobel prize because of her work with radioactivity, and a unit of radioactivity (yes, we know — not the SI unit) is a Curie. However, Curie also left something else behind inadvertently: radioactive residue. As the BBC explains, science detectives are retracing her steps and facing some difficult decisions about what to do with contaminated historical artifacts.

Marie was born in Poland and worked in Paris. Much of the lab she shared with her husband is contaminated with radioactive material transferred by the Curies’ handling of things like radium with their bare hands.

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Using A Videocard As A Computer Enclosure

June 10, 2025 by Maya Posch 9 Comments

The CherryTree-modded card next to the original RTX 2070 GPU. (Credit: Gamers Nexus)

In the olden days of the 1990s and early 2000s, PCs were big and videocards were small-ish add-in boards that blended in with other ISA, PCI and AGP cards. These days, however, videocards are big and computers are increasingly smaller. That’s why US-based CherryTree Computers did what everyone has been joking about, and installed a PC inside a GPU, with [Gamers Nexus] having the honors of poking at the creatively titled GeeFarce 5027POS Micro Computer.

As CherryTree describes it on their website, this one-off build was the result of a joke about how GPUs nowadays are more expensive than the rest of the PC combined. Thus they did what any reasonable person would do and put an Asus NUC 13 with a 13th gen Core i7, 64 GB of and 2 TB of NVMe storage inside an (already dead) Asus Aorus RTX 2070 GPU.

In the [Gamers Nexus] video we can see that it’s definitely a quick-and-dirty build, with plenty of heatshrink and wires running everywhere in addition to the chopped off original heatsink. That said, from a few meter away it still looks like a GPU, can be installed like a GPU (but the PCIe connector does nothing) and is in the end a NUC PC inside a GPU shell that you can put a couple of inside a PC case.

Presumably the next project we’ll see in this vein will see a full-blown x86 system grafted inside a still functioning GPU, which would truly make the ‘install the PC inside the GPU’ meme a reality.

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Two Bits, Four Bits, A Twelve-bit Oscilloscope

June 10, 2025 by Al Williams 4 Comments

Until recently, hobby-grade digital oscilloscopes were mostly, at most, 8-bit sampling. However, newer devices offer 12-bit conversion. Does it matter? Depends. [Kiss Analog] shows where a 12-bit scope may outperform an 8-bit one.

It may seem obvious, of course. When you store data in 8-bit resolution and zoom in on it, you simply have less resolution. However, seeing the difference on real data is enlightening.

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Generating Plasma With A Hand-Cranked Generator

June 10, 2025 by Maya Posch 12 Comments

Everyone loves to play with electricity and plasma, and [Hyperspace Pirate] is no exception. Inspired by a couple of 40×20 N52 neodymium magnets he had kicking around, he decided to put together a hand-cranked generator and use it to generate plasma with. Because that’s the kind of fun afternoon projects that enrich our lives, and who doesn’t want some Premium Fire™ to enrich their lives?

The generator itself is mostly 3D printed, with the magnets producing current in eight copper coils as they spin past. Courtesy of the 4.5:1 gear on the crank side, it actually spins at over 1,000 RPM with fairly low effort when unloaded, albeit due to the omission of iron cores in the coils. This due to otherwise the very strong magnets likely cogging the generator to the point where starting to turn it by hand would become practically impossible.

Despite this, the generator produces over a kilovolt with the 14,700 turns of 38 AWG copper wire, which is enough for the voltage multiplier and electrodes in the vacuum chamber, which were laid out as follows:

Circuit for the plasma-generating circuit with a vacuum chamber & hand-cranked generator. (Credit: Hyperspace Pirate, YouTube)

Some of our esteemed readers may be reminded of arc lighters which are all the rage these days, and this is basically the hand-cranked, up-scaled version of that. Aside from the benefits of having a portable super-arc lighter that doesn’t require batteries, the generator part could be useful in general for survival situations. Outside of a vacuum chamber the voltage required to ionize the air becomes higher, but since you generally don’t need a multi-centimeter arc to ignite some tinder, this contraption should be more than sufficient to light things on fire, as well as any stray neon signs you may come across.

If you’re looking for an easier way to provide some high-voltage excitement, automotive ignition coils can be pushed into service with little more than a 555 timer, and if you can get your hands on a flyback transformer from a CRT, firing them up is even easier.

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