That website is really lacking any worthwhile details. Are they just fishing for venture capital at this point?
Metal Without Mining
31–40 of 82 posts
Re: Metal Without Mining
#32Earlier quoted context omitted.
Eh no. Oceans are big. Really big. Unbelievably big even. We're talking about filtering tiny fractions of ocean water, and nowhere close to all of it. Literally a drop in the ocean in comparison. So, no. This is not a serious concern.
Speaking strictly of mineral removal this rings true. However, processing large volumes of seawater can still have a detrimental effect on the local ecosystem, because pumping large volumes of seawater is extremely stressful to all of the seawater-loving organisms that get pulled along for the ride.
See also the trouble around desalinization plants.
In absolute terms, we couldn't hope to remove enough salt from the oceans to be even so much as detectable in the absolute sense, but in local terms water with increased salinity can cause problems. Oceans are not hives of life everywhere you look, it's really just in spots, and those spots are generally right where we want to be and to put our desalization plants.
Plus the high-salt and normal ocean water are much more resistant to mixing than our intuition would suggest. They will eventually mix, but the high-salt water can go a surprisingly long way first.
Re: Metal Without Mining
#33If you are wondering "how" they are doing this, I believe this company is the externalization of this research: https://www.innovationnewsnetwork.com/new-method-extract-mag... (Kind of hard to pin down exactly since they don't say a lot about how they are doing it, but a quick check suggests this is the only "new" thing in extracting magnesium recently and Magrathea is a young company[1]) [1] https://www.crunchbase.c…
They mention that they are doing electrochemistry. A huge portion of historical magnesium production is from electrolysis, including the only operating plant in the US. Past methods have used lime to precipitate magnesium (Dow) or evaporation ponds to concentrate it (the current Utah plant). Probably the new thing they are doing is using something like Chlor-Alkali to make base that precipitates the magnesium instead of using lime. Then the electrolysis of molten magnesium salts would be similar to products of today. There is some chance they have improvements in these areas, but there are really only so many options. The job descriptions they've posted support this hypothesis.
Recently most magnesium comes from China. They mine ore, throw it in a coal-fired furnace along with some reducing agents, then collect pure magnesium vapor. This process is more labor and energy intensive, but has significantly less CAPEX. Works for China.
Chlor-alkali is more expensive than lime and the back-end electrolysis is more expensive than thermal reduction. So I'd be skeptical they are going to lower costs without some kind of CAPEX reducing magic for molten salt electrolysis.
Re: Metal Without Mining
#34it looks like somebody's school homework
Re: Metal Without Mining
#35There are two major ways of producing magnesium [1]:
1) Electrolytic production from anhydrous magnesium chloride, similar to the electrolytic production of aluminum.
2) The Pidgeon process, which currently dominates Chinese (and world) magnesium production. It distills magnesium vapor under vacuum from a heated mixture of ferrosilicon and magnesium-calcium oxide (calcined dolomite).
The Pidgeon process has a high global warming potential because of the coal used to produce the ferrosilicon input and to heat the retorts. The electrolytic process has a lower global warming potential, especially if using low-carbon electricity, but historically sulfur hexafluoride has been used as a protective cover gas for the metal during electrolytic production. This gas has a staggering global warming potential 23,900 times that of CO2 [2] so incidental leakage of even small quantities can have a high climate impact.
The "without mining" part is not novel. Dow Chemical produced electrolytic magnesium from seawater without mining at Freeport, Texas from 1941-1998, until lower cost foreign magnesium made it uneconomical:
https://www.chemicalonline.com/doc/dow-to-exit-magnesium-bus...
Reading the company's rather sparse public info, it looks like this is a revival of the same basic kind of process as Dow used. But since it's focused on certifying a low GWP for its magnesium, the company will not use sulfur hexafluoride. ("We’re piloting a new generation of electrolytic production technology that is inherently carbon neutral, removing the need for coal and carbon-intense reagents like FeSi and SF6.")
They don't say it directly but they also must be using clean electricity for the electrolysis, otherwise the metal would still be fairly CO2-intensive.
Unfortunately, the latest news item from their news page is about a threat to their business:
"State of Utah denies US Magnesium’s request to extend canals into the Great Salt Lake threatening shutdown of the only American magnesium producer"
https://sltrib.pressreader.com/article/6830844853434424
[1] https://ro.uow.edu.au/cgi/viewcontent.cgi?article=2295&conte...
[2] https://en.wikipedia.org/wiki/Sulfur_hexafluoride#Greenhouse...
Re: Metal Without Mining
#36If you're wondering about where the name Magrathea comes from:
Re: Metal Without Mining
#37It's not "impossible" to decarbonize the production of aluminum without driving up cost, as the page claims. Once green electricity and hydrogen is cheaper than CO2-emitting energy, this will be possible and even profitable.
Re: Metal Without Mining
#38It's not "impossible" to decarbonize the production of aluminum without driving up cost, as the page claims. Once green electricity and hydrogen is cheaper than CO2-emitting energy, this will be possible and even profitable.
Isn't new renewable power cheaper than new C02 power?
Re: Metal Without Mining
#39Earlier quoted context omitted.
Correct, the question that should be asked here is what happens to all of the water after we've removed the minerals we need from it? Do we just pump it back into the ocean? The outlet would need to be far enough away from the inlet to avoid dilution. What impact does that have on marine life? We know that concentrating those minerals into brine when we extract water through desalinization is harmful so how harmful i…
My idea is to combine this with desalination. California could permanently end its droughts and become a major magnesium supplier in one swell foop.
You'd also need to think up good uses for the sodium chloride or dump it somewhere. The sulfate, potassium and calcium would probably be useful if they could be easily separated but the sodium and chloride ions are by far the majority and are not going to be profitable in comparison to the current operations we use to obtain them.
Re: Metal Without Mining
#40It's not "impossible" to decarbonize the production of aluminum without driving up cost, as the page claims. Once green electricity and hydrogen is cheaper than CO2-emitting energy, this will be possible and even profitable.
The problem with decarbonizing is not being solved with green electricity and hydrogen. The (direct) emissions come from the carbon anodes that are consumed in the process. They are usually made from petroleum coke, aka they're fossil fuels.
Alternatives are being developed, but have a somewhat troubled history. Alcoa announced in the early 2000s that they are only months away from deploying inert anode technology. They're still not there (though still working on it in a project called elysis).