Rare Earth Elements from Waste | Hacker News Reader

Rare Earth Elements from Waste

science.org

5 pointsavg_dev2 comments

I heard about this paper (which I haven't read) on the radio, where there was an interview with James Tour, who talked about it: https://www.cbc.ca/radio/quirks/mar-5-climate-change-and-hea...

Abstract:

> Rare earth elements (REEs) are critical materials in electronics and clean technologies. With the diminishing of easily accessible minerals for mining, the REE recovery from waste is an alternative toward a circular economy. Present methods for REE recovery suffer from lengthy purifications, low extractability, and high wastewater streams. Here, we report an ultrafast electrothermal process (~3000°C, ~1 s) based on flash Joule heating (FJH) for activating wastes to improve REE extractability. FJH thermally degrades or reduces the hard-to-dissolve REE species to components with high thermodynamic solubility, leading to ~2× increase in leachability and high recovery yields using diluted acid (e.g., 0.1 M HCl). The activation strategy is feasible for various wastes including coal fly ash, bauxite residue, and electronic waste. The rapid FJH process is energy-efficient with a low electrical energy consumption of 600 kWh ton−1. The potential for this route to be rapidly scaled is outlined.

Basically, there's a way to use https://en.wikipedia.org/wiki/Fly_ash (from coal power plants) and electronic waste to produce rare earth elements. I thought it was amazing.

One of the things that bugs me the most about computing is the disposable nature of our electronic goods and the waste it produces and the slave/child labor involved in mining these elements. I thought, maybe we won't have to any more.

Anybody who knows more have any thoughts?

It is a great idea. The problem is often in the smelters, and other manufacturing processes. They are designed for certain element streams. For example we organized delivery of 100,000+ tonnes of copper contaminated soil, and in another case lead contaminated soil to go by train to copper and lead smelters (processors.) So instead of paying to send to a hazardous waste treatment facility - where it would have been all buried, and would cost millions in disposal fees, the contaminated soil had value. Unfortunately, the value was so low, that it barely paid for hauling cost. (Still better than disposal cost, though.) The waste stream was too rich. The smelters had to dilute, and handle the waste streams separately. If it was a continuous process, then they could design a system to continuously handle it. In other words, this is possible, but as in most processing operations, it would require a comprehensive buy in, from all over the world, or across the USA, or across Europe, for example. With organising it could work. But everything is independent and dissociated. Similar to other problems we have, with electric power distribution, water management, etc.

Reply on news.ycombinator.com