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NNadir

(33,517 posts)
Sat Sep 12, 2020, 09:21 AM Sep 2020

Sustainable Iron-Making Using Oxalic Acid: The Concept, A Brief Review of Key Reactions...

The paper I'll discuss in this post is this one: Sustainable Iron-Making Using Oxalic Acid: The Concept, A Brief Review of Key Reactions, and An Experimental Demonstration of the Iron-Making Process (Phatchada Santawaja, Shinji Kudo,* Aska Mori, Atsushi Tahara, Shusaku Asano, and Jun-ichiro Hayashi, ACS Sustainable Chem. Eng. 2020, 8, 35, 13292–13301)

There's a rumor going around that coal is dead, often accompanied with the delusional statement that so called "renewable energy" killed it. These statements are Trump scale lies. In the 21st century, has coal proved to be the fastest growing source source of energy, growing in terms of primary energy production by more than 63 exajoules from 2000 to 2018, faster than even dangerous natural gas, which was the next fastest growing source of primary energy, having grown by 50 exajoules from 2000 to 2018, roughly 700% percent faster and 600% faster than so called "renewable energy" in this period, ignoring biomass combustion, and hydroelectricity, the former being responsible for about 1/2 of the six to seven million air pollution deaths each year, the latter having destroyed pretty much every major riverine system in the world.

2019 Edition of the World Energy Outlook Table 1.1 Page 38] (I have converted MTOE in the original table to the SI unit exajoules in this text.)

One of the reasons that coal has grown so fast in this century is that poor people around the world - who basically we pretend don't exist - have not agreed to remain desperately impoverished so rich people in the post industrial Western world can pretend that their "Green" Tesla electric cars are powered by solar cells and wind turbines.

It would be a gross understatement to say that I am "skeptical" that so called "renewable energy" will do anything at all to address climate change. Half a century of cheering for it has done zero to prevent California, Australia, and indeed even the arctic from catching fire.

My least favorite form of so called "renewable energy" is represented by the wind industry, and one of my biggest criticisms of this benighted industry is its high mass intensity, particularly with respect to its high steel requirements, coupled with the short life time on average of wind turbines, typically well under twenty years.

There is essentially no steel that is not made on industrial scale with coal, today: Coal fires convert anthracite coal into coke, with the coke being used to reduce iron, alloying it with carbon, to make steel.

That's a fact. Facts matter.

Even if no energy were produced using dangerous fossil fuels - the use of which is rising, not falling - the problem of steel would remain, although it is possible that we may, to some extent, enter the age of titanium, are well into the age of aluminum, but the electrochemical reduction of both of these metals depend on carbon electrodes made from dangerous fossil fuels, coal coke and petroleum coke respectively.

This dependence is why this paper caught my eye.

From the introduction:

Iron and steel are materials indispensable to modern society. Global crude steel production rose by 3.9% from 1.71 Gt in 2018 to 1.78 Gt in 2019, and continued growth is projected in the years to come.(1) The iron and steel industry is, however, one of the most energy-intensive industrial sectors.(2?7) CO2 emissions from this industry amounted to approximately 2.0 Gt in 2019, accounting for 24% of the total amount emitted directly from industries.(8) The majority of CO2 is generated in the iron-making process, which generally employs a blast furnace (BF). The BF is a sophisticated technology that is used to produce a massive amount of iron continuously. CO2 emissions are unavoidable during this process as the technology relies on fossil fuels, coal in particular, for reducing iron oxides in the iron ore and providing heat to maintain a furnace temperature of up to 2,200 °C.(6,9) Among all energy services and industrial processes, the iron and steel industry, which inevitably relies on fossil fuels, is considered to be in the category of “difficult-to-eliminate emissions”.(7) The development of alternative iron-making technology is thus vital to the global goal of building a sustainable society.

Extensive R&D efforts have been invested in alternative approaches to iron-making from the iron ore, which are largely classified into two types: direct reduction (DR) and smelting reduction processes.(2?6,9?12) In DR, the iron oxides in iron ore are reduced using reducing gas (H2 and CO) produced from natural gas or coal in reactors such as shaft furnaces and fluidized bed reactors. The reduction occurs at temperatures below the melting point of iron, producing so-called direct reduced iron or sponge iron. On the other hand, smelting reduction produces molten iron like a BF using a two-step process consisting of the solid-state reduction, followed by smelting reduction. The developed technologies, e.g., MIDREX for the DR and COREX, FINEX, ITmk3, and Hismelt for the smelting reduction, have been commercialized or are under demonstration.(3,6,13) The advantages of these alternative iron-making processes over BF include the lack of a need for coke, lower CO2 emissions, and lower capital/operation costs. However, they do not address the fundamental problems posed by the use of a BF because of their reliance on fossil fuels and harsh operating conditions. From this viewpoint, there are limited studies on potential sustainable iron-making methods...


There are many routes to oxalic acid with carbon dioxide as a starting material; one can come across papers along these lines regularly, some of which involve electrochemical reduction. Oxalic acid is moderately toxic, and is frequently utilized in commercial wood preservative products because it suppresses the viability of microorganisms that hydrolyze cellulose and lignin, the main constituents of wood. Famously the inability of the American Chestnut tree to synthesize oxalic acid when compared to the ability of the Chinese Chestnut to produce this biotoxin, led to the near extinction of the former. (Recently there has been promising work to insert oxalic acid generating genes into American Chestnuts.)

Oxalic acid is the simplest diacid, having the formula C2H2O4. It may be thought of as dimer formed by the elimination of two hydrogens from formic acid, the simplest carboxylic acid.

The overall scheme of this oxalic acid iron reduction scheme is shown in the following graphic from the paper:



The caption:

Figure 1. Concept of iron-making process proposed in this study. OA: oxalic acid.


The authors note that among many acids designed to solvate iron oxides - which are clearly insoluble in water - is in fact oxalic acid, although mineral acids are more commonly utilized in this process.

They write:

During leaching, iron is chelated by the organic acids and selectively removed from the material in a stable form. Among the organic acids, oxalic acid has been studied extensively and suggested to be the most effective acid for this purpose due to its high acid strength and good complexing ability...

...There are several factors affecting the rate of iron dissolution. Among them, pH of the initial solution, acid concentration, and temperature have been intensively studied.(17?24,26,28,30?32) The rate of iron dissolution is maximized when the pH of the oxalic acid solution is in the range of 2.5–3.0 because bioxalate anions (HC2O4–), which are responsible for iron dissolution, are the most abundant species in this range.(24,27,28) However, the pH of 2.5–3.0 is difficult to control with oxalic acid due to its low concentration, corresponding to 1–3 mmol/L, and, moreover, the low concentration is often insufficient for iron oxide removal. Therefore, the oxalic acid solution is typically prepared with the addition of its alkali salt as a buffering agent...


Dissolution is improved with the application of heat, which is unsurprising.

It is known that iron oxalate complexes can be reduced photochemically - this reaction has been used in actinometric devices - but the rate is slow, so the authors examine pyrolysis of the complex.

Thermal treatment of metal oxalates is an approach used to synthesize nanocrystalline metals or metal oxides. Fe(II) oxalate dihydrate is the typical precursor, and its thermal behavior has been investigated in some reports.(50?54)Figure 2 presents mass release curves for pyrolysis of Fe(II) oxalate dihydrate under a flow of N2 or 50% H2/N2, analyzed in this study. Upon heating, Fe(II) oxalate dihydrate starts to release water, forming anhydrous Fe(II) oxalate that is thermally stable up to around 300 °C. At higher temperatures, Fe(II) oxalate pyrolyzes with the release of CO and CO2 to form metallic iron, iron oxides, or iron carbides. The chemical form and composition of the iron product are significantly influenced by the atmosphere during the occurrence of pyrolysis. Although the reaction mechanism that determines the chemical form is still contested, most studies have identified FeO as the primary product during pyrolysis under an inert atmosphere, which was also confirmed in Figure 2 by the relative mass of 39.9%, corresponding to the generation of FeO, above 420 °C.


Figure 2:



The caption:

Figure 2. Mass release curves of Fe(II) oxalate dihydrate in the pyrolysis under a flow of N2 or H2/N2 (50%): sample 5 mg, heating rate 10 °C/min, and gas 300 mL/min.


The authors avoid the hand waving "we're saved!" nonsense that often accompanies popular descriptions of lab scale processes when discussing the reduction of carbon dioxide to oxalic acid:

Oxalic acid has been synthesized on a large scale worldwide. Because demand is not necessarily high, the synthetic route and feedstock used differ by countries and companies according to their situation. The employed feedstock has been sugars (e.g., starch and sucrose), CO, ethylene glycol, and propylene.(55) Alternatively, there has been no industrial process that uses CO2 as the feedstock, and only a few academic works have reported successful synthesis despite its attractiveness. This clearly shows the technical difficulty of CO2 activation in forming C–C bonds.

A robust approach to the reductive coupling of CO2 is electrochemical conversion.(56?58) For example, atmospheric CO2 is spontaneously captured and electrochemically converted into oxalate over copper complex, mimicking the natural photosynthetic transformation of CO2.(59) However, electrochemical conversion requires costly catalysts and organic solvents, which are unlikely candidates as an industrial method to produce cheap oxalic acid and iron. A recent report by Banerjee and Kanan(60) stood out in this regard, revealing the generation of oxalate only by heating cesium carbonate in the presence of pressurized H2 and CO2. The carbonate anion was replaced by formate anion from CO2. Then, the formate anion was coupled with CO2 to selectively form cesium oxalate with a yield of up to 56% (with respect to the carbonate), including other carboxylates at 320 °C and 60 bar. Nevertheless, the technical development of CO2 utilization for oxalic acid synthesis is still in its infancy.


In its infancy.

Given my personal focus on the utility of fission products, I note that hot cesium is one of the most prominent fission products, especially when freshly captured from used nuclear fuels. In addition, gamma radiation is known to produce carbon dioxide radicals, which may well accelerate this process.

But it's a very long way from here to there...

In any case, the authors experimentally (lab scale) use both photochemical and pyrolytic reduction of iron oxalate.

The following table shows the composition of the iron in each case.



XRD (X-ray diffraction) of the two processes:



The caption:

Figure 3. XRD pattern of feedstock and solid products from photochemical reduction (SSTP2) and pyrolytic reduction (SSTP3).


Scanning electron microscope (SEM) images of the product:



The caption:

Figure 4. SEM image of feedstock and solid products from photochemical reduction (SSTP2) and pyrolytic reduction (SSTP3).


In these graphics IO-A and IO-B refer to two different natural iron ores; CS refers too "converter slag" which represents iron recovered that would otherwise be waste.

Yields:



The caption:

Figure 5. Iron recovery at each step of conversion.


A graphic representation of the dissolution process using oxalic acid:



All papers on processes have to make a stupid genuflection to the idea that solar energy will save the world, even though it won't:

The caption:

Figure 7. Photochemical reduction of dissolved iron with solar simulator at 180 klx and room temperature: time-dependent change of conversion to FeC2O4·2H2O and Fe2+ or Fe3+ concentration.


An attempt to build a plant around this idea would be to deliberately build a plant that is a stranded asset for large periods of a twenty four hour day, not to mention days when it rains, snows, or the sky is occluded by the smoke of uncontrolled fires because solar energy did not address climate change even after trillions of dollars and worldwide screams of cheering.



The caption:

Figure 7. Photochemical reduction of dissolved iron with solar simulator at 180 klx and room temperature: time-dependent change of conversion to FeC2O4·2H2O and Fe2+ or Fe3+ concentration.


On that score, a schematic of batch productivity:



The caption:

Figure 8. Iron productivity as functions of reaction time and iron concentration in a batch operation.


Excerpts of the conclusion and caveats against "We're saved!"

A three-step iron-making process was proposed and investigated using different types of iron-containing materials. The experimental results showed promising performance as an iron-making method. The chemical selectivity of iron dissolution and photochemical reduction enabled the obtainment of product iron with a purity of 80.5–99.7 wt % (on a metal basis) from the feedstocks consisting of 33.9–93.3 wt % iron. The highest temperature used for completing the reduction to metallic iron was only 500 °C due to the pyrolysis characteristics of Fe(II) oxalate. On the other hand, the iron dissolution step determined primarily the overall yield and purity of the produced iron. Ca and Mg reacted with oxalic acid to form water-insoluble oxalates, causing its shortage for the iron dissolution. Transition metals such as Mn were inevitably included in the produced iron. As a result, iron recovery from CS, having high contents of these unwanted metals, was limited to 15.8%. The iron recoveries from IO-A and IO-B were 91.5 and 88.3%, respectively. The proposed method also allowed for the use of powdered ore, which has not been the feedstock in conventional iron-making except for the smelting reduction. The availability of diverse feedstocks will be a great advantage considering the decreasing quality of iron ore globally...

...A consideration is necessary for particle sizes of the feedstock iron ore, Fe(II) oxalate, and iron product. In the present experiment, fine particles of feedstock with sizes below 38 ?m were used to avoid possible influences of mass transfer on the iron dissolution. Fe(II) oxalates, obtained in the photochemical reduction, were also fine powders in the order of micrometers. In large-scale practical applications, technical difficulties would be found in feeding into and recovering from reactors for such small particles. Another concern is that small sizes of reduced iron product cause a low resistance to spontaneous ignition, which is also a problematic property of direct reduced iron.

The synthesis of oxalic acid from CO2 is vital to process sustainability. Direct synthesis is an emerging area of research but has a long way to go to become an industrial technology. Indirect synthesis via CO or biomass is a realistic option if a conversion system with economic and energetic rationality is found. It is also important to confirm the generation of CO2 and CO from iron-making, according to the proposed stoichiometry, and to design reactors that enable their recovery...


It's a cool paper on an area of research that I would certainly think is merited, not that anyone cares what I think.

Have a nice weekend. Please be safe and respect the safety of others.
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ihas2stinkyfeet

(1,400 posts)
1. thx for this. i love it. brains over braun.
Sat Sep 12, 2020, 11:31 AM
Sep 2020

i want to do some small wind on my home. i live a few blocks from lake mich, we either have strong sun or strong winds.
i want to build a cylindrical turbine out of junk metal.
and since i have hot water heat, i want to do hot water based solar. they tell me it doesnt get hot enough to do my system any good, but i dont believe them.
w a heat exchanger, i could have air as well.

but rooftop turbines made of recycled plastic seem like they would be a great answer. they make park benches around here out of milk jugs.
but those clear drink bottles ought to be able to be unzipped, and zipped back into a turbine that would be both light and tough. and flexible. cuz rigid is not necessary.

very interesting stuff you post hatrack. i am a fan.

 

ihas2stinkyfeet

(1,400 posts)
3. no.
Sat Sep 12, 2020, 01:31 PM
Sep 2020

off track from the chemistry part, but not from the original statement that renewables arent the answer to climate change.

NNadir

(33,517 posts)
4. Thanks, then. I wasn't sure how to interpret...
Sun Sep 13, 2020, 09:49 AM
Sep 2020

...the reference to Hatrack - the fine poster at over E&E when it comes to keeping track of climate changes consequences - although I obviously hold a rather contemptuous position with respect to other posters in E&E, in particular the dumb ass anti-nukes who are responsible in my view, for this disaster. I ignore them, and obviously they ignore me.

I seldom write there any more.

As for whether so called "renewable energy" is doing anything with respect to climate change after 3 trillion dollars in 20 years and half a century of wild cheering for it, events rather speak for themselves.

I have noticed why the world is burning; even if it seems to escape much attention.

This morning's weekly data at Mauna Loa shows that we are 25.11 ppm higher than we were just ten years ago. It is only 8th time in over 2,320 such readings that a value greater than or equal to 25.00 ppm has ever been recorded for this piece of data, going back almost half a century. All eight such readings took place in the last two years, five of those eight this year.

So much for all our wind turbines...

I am very clear in my view of so called "renewable energy" is all about. I view our enthusiasm for it, our belief that it will work, on the left rather as a form of our answer to the right wing's belief in creationism.

I wish I could say that we on the left are innocent with respect to climate change; but regrettably, I can't. We are, quite literally, tilting at windmills. Our hatred of nuclear science borders on criminal in my view, and I am unafraid of saying so.

Enjoy the rest of the weekend and thanks for the complement.

 

ihas2stinkyfeet

(1,400 posts)
5. ooo. my bad.
Sun Sep 13, 2020, 10:08 AM
Sep 2020

read so many good hatrack posts i thought it was his.

i'm a fan of yours, too. but having worked for a company that built nuke plants, i wonder if the cradle to grave costs can ever add up.
they built braidwood. and right now comed's zion is in mothballs while they try to figure out how do decommission it. and it sits on lake michigan, water source for millions of ppl.
and there is nothing unusual about any of that.

i have hopes for the next gen. and do know that we must rely on those still operating for as long as they can be safely run.

i still dont get why the distributed grid isnt much of a thing. comed has done a lot of upgrades, and when i finally get some solar up, i know i will get paid instead of paying.
i own several rental properties, all w great souther exposures, and all but one w flat roofs.
but the panels have to get better before i go pv. i have my eye on a electric vette, tho. will at least put up some panels to charge that. planning to put a roof over some parking spaces to do that. a worthwhile investment, as parking is at a premium where i am. can get $100/mo for uncovered parking. sure i can get $200 for covered parking w free charging.

planning to upgrade my heating in my 2 2flats. want to do nat gas air. used to have a coleman pop-up that had a fridge you could run on the bottled gas.
all utilities paid w air is worth an extra $200/mo. all it will cost me is initial investment. which i can easily afford. that's just how i roll. i am 66, and i have upgraded all my properties in a way that i dont have to do this shit again when i am 99.
my momma didnt raise no dummies. we were poor, and she was a child of the depression. she taught me that frugal and cheap are not the same thing.
too bad so many in that generation grew up cheap instead. cuz that's how i got rich.

NNadir

(33,517 posts)
6. But you don't wonder how the "cradle to grave" costs of climate change "add up?"
Sun Sep 13, 2020, 10:27 AM
Sep 2020

You may be paying selective attention, I think.

The failure to address climate change is not "cheap" and it's clearly not "frugal."

I would say the destruction of large tracks of our Western states doesn't "add up."

Zion was built on 1950's and 1960's technology. Has sitting there harmed anyone at all?

The nuclear industry is more than half a century old. In that entire period, it hasn't killed anything like the number of people as will die in the next three days from air pollution.

I hear a lot from people who want to tell me about their personal utility bills, and how they "add up" to something or another.

I view the world on a macro scale. The world doesn't add up. History will not forgive us, nor should it.

 

ihas2stinkyfeet

(1,400 posts)
7. oh no. i didnt say or mean that.
Sun Sep 13, 2020, 10:37 AM
Sep 2020

just that nukes are riding the tiger.
the rest is screwing the pooch, to be sure.

so far zion is safe in mothballs. and thankfully this area is not prone to natural disasters. so, likely it will stay static till it can be taken down.
but can we say the same about vermont yankee? or other coastal plants?
power is important, but water truly is life.

NNadir

(33,517 posts)
8. If Zion, or for that matter, Fukushima's destroyed reactors sit unattended as long as the...
Sun Sep 13, 2020, 11:06 AM
Sep 2020

...Parthenon sat unattended, the loss of life will still be trivial.

If the Zion decommissioned reactors were cracked open by a rare Earthquake, how many people would die from the event? People often act as if that were to happen, an atom of zirconium-93 would immediately tunnel into their brains and kill them. Is this rational?

Would as many people die as would have died had coal plants been built there instead and operated normally?

I often have occasion to drive past an abandoned steel plant. There are huge piles, small mountains, of slag outside it. The full plant is rotting and has become something of a tourist attraction.

I have always wanted to check some runoff from those slag mountains with an ICP/MS to see what exactly what elements are in it. Since I know something about this topic, since I regularly read environmental science journals, it's a scary thought.

Does anyone ever wonder if an atom of neurotoxic mercury will migrate immediately to their brains and turn them into a Trump voter?

You know, wind turbines use an awful lot of steel; and wind turbines generally don't last twenty years before they need to be replaced.

How "renewable" are they, exactly?

Nuclear power does not need to be risk free in the imaginations of every person who fails to engage in critical thinking to be vastly superior to everything else. It is decidedly not risk free. It is simply lower risk than everything else, including the case where no one has electricity at all, even though electricity itself - from any source - is not risk free.

The wind industry is not sustainable. It's a short term affectation that will do great damage to the future of all humanity: It's most dangerous property - not the only dangerous property but the worst among them - is that has failed, is failing and will always fail to address climate change. The wind industry is centuries old. Beginning in the 19th century, it was ultimately abandoned before being revived by reactionaries. There is a reason it was abandoned.

We'd do better if we asked ourselves what that reason was.

 

ihas2stinkyfeet

(1,400 posts)
9. well i mostly do agree w you.
Sun Sep 13, 2020, 12:44 PM
Sep 2020

but since lake mich is MY water supply, not just personally, but for my urban farm, i get a bit touchy about the subject.
the new madrid fault is unlikely to shake things that far north, but...

and tho tornadoes are rare that far north, that isnt much of a threat either. now. but then again, we arent supposed to have them in the big city, but one touched down about 6 blocks from me a couple weeks ago. and we have had 2 derechos run along the lakefront in the last few years. the 2nd ripped through my hood.
the loss of big trees here is incalculable. giant oaks and maples uprooted.
personally i am lobbying to replace them w the native birches. and i am aware that those old trees werent sequestering much carbon but the new ones will.
tho all that rotting tree mass will likely outpace that for many years to come. few are smart enough to engage in hugelkultur, which is the basis of my farm.

and i wont take but a few degrees of warming to move the tornado corridor that far north. just south and west of here by about 100 miles is the most active tornado alley outside of tx/ok.

so, yeah, the thought of zion cracking open keeps me up some nights. water for 8 million people. and all the hurbs in this horto.
it would make the fires burning now pale in comparison.

and like i said- recycled plastic small wind on every roof top in chi would make a real dent. but even in big turbines, imho. they could be scaled down and make of polymer plastic w no loss of capacity. they would be quieter, too.

maybe some day we can talk about ag. restorative ag is my bag.
my farm has a HUGE negative carbon footprint. less than 1/4 acre, too.

NNadir

(33,517 posts)
10. You are placing a very unlikely could over a very real "is."
Mon Sep 14, 2020, 08:35 AM
Sep 2020

Laying awake over Zion and the water supply is irrational as he'll.

The threat actually being realized to water supplies by climate change is not.

You may or may not be interested in the science surrounding Fukushima, where operable reactors failed discharging much of the volatile products of fresh nuclear fuel directly into the environment.

Radiation did not kill 8 million people. It didn't kill 20,000 people although seawater did kill that many people in the event, not that anyone is talking or worrying about the safety of coastal cities or talking about banning them. The only thing that matters in this sick and arbitrary focus is the radiation.

Today 19, 000 people will die from air pollution but no stays up at night worrying about the toxic stuff people breathe because of an illiterate fear of small concentrations of radioactive material leads to the dangerous and deadly decisions to not build nuclear power plants.

Nuclear energy saves lives. It follows that anti-nuclear fear and ignorance kills people.

We are even close to agreement on this issue.

 

ihas2stinkyfeet

(1,400 posts)
11. honest question- i dont know. how many ppl die mining nuclear materials?
Mon Sep 14, 2020, 09:06 AM
Sep 2020

specifically, i mean. i know it is all highly mechanized these days. but it is a dangerous business in general. there are many ppl exposed along the way

i agree w you about the hidden environmental cost of renewables. but you ignore the amount of steel and concrete that go into nuke plants. and whatever deaths come from mining and may come from waste at the end.
and people on the clean up crew at fukashima did die.

i think we can both agree that the next gen of both technologies needs to assess the cradle to grave costs. that i why i say recycled plastic turbines, and why i want one made of junk metal.
i only vaguely know that the next gen of nukes being looked at a radically different. but i still dont see those materials, however much they may use, arriving at the gates w/o a heavy environmental price tag.
unless they use spent fuel from old reactors or recovered from fracking waste, i cant see them being worth it. i may be wrong. i have no numbers.


and of course, there is nothing rational about the things that keep me up nights.
i also worry about the storms that knocked down all those trees that arent supposed to happen here. if one hit the water treatment plant on the lake, many people would lose their access to water. but not forever. and the fish wouldnt die.

and this year's heat has been brutal for me and for my farm. tho we havent had any 100º days like we did 6 yrs ago. it has been nothing but hot and dry since may. only the fact that i have access to lake water, and that i practice hugelkultur, which uses very little water, explains why my farm doesnt look like my neighbor's brown lawns. i have kidney issues, and this shit nearly killed me. i have barely been able to keep it all alive.
it's still all green, but most of it is the stuff i didnt plant. i lost many of the things i did.

i joke about having lakefront property some day if sea level rises, but it isnt a joke. where i live is halfway between what used to be the shore and what is now.

so, i can walk about chew gum. how about you?

hunter

(38,311 posts)
12. Many modern nuclear power schemes would not require any further uranium mining.
Mon Sep 14, 2020, 05:06 PM
Sep 2020

They'd be powered by light water reactor "waste" and depleted uranium.

Stuff that's already been mined.

For example:

https://en.wikipedia.org/wiki/TerraPower

And when that waste is gone, more than a century from now, we might turn to a wide variety of mine tailings.

Beyond that, uranium extracted from the ocean in desalinization schemes... essentially forever so long as we humans limit our numbers to something sustainable.






NNadir

(33,517 posts)
14. I agree. This said there are many paths for the single electron transfer reduction of iron.
Mon Sep 14, 2020, 05:31 PM
Sep 2020

I just sighed and forgot about that part, after mumbling some nonsense to myself about krypton-85.

The real reason I pointed out this fine paper - and it is a fine paper - is to draw attention to the often overlooked fact that iron reduction is dependent on carbon from dangerous fossil fuels and that real progress is still on a lab scale.

I believe that we can ultimately displace this dependence, not only for iron but for all other industrial metals, but it is not something that is simple, and the fact is that so called "renewable energy" is not even remotely up to the task, a task - especially for the wind industry - for which it depends for its existence.

 

ihas2stinkyfeet

(1,400 posts)
15. some day we will mine the landfills.
Mon Sep 14, 2020, 09:06 PM
Sep 2020

personally, i think it is possible today, but the economics of it are a different thing.

but grinding big rocks into powder to make beer cans when you can pick up refined aluminum in any alley in chi cant make economic sense, either.

ppl need to get used to paying the green tax.
i get shit for asking $10/doz for eggs, when that is the farmers market price.
foodies are happy to pay. and health nuts. but normal ppl, not so much.
and tho my inputs would allow me to sell my organic heirloom tomatoes at a price that competes w mexican imports, fuck if i will.

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