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Gallium cannot be produced at scale because it does not form concentrated ores in nature. It cannot be usefully mined directly. The only reason it is relatively

Gallium cannot be produced at scale because it does not form concentrated ores in nature. It cannot be usefully mined directly. The only reason it is relatively inexpensive is that there is limited demand for the minuscule quantities that are currently produced. Gallium is currently supplied by reprocessing the waste from other convenient metal ores to extract the traces of gallium. Even if we maximized gallium extraction from these waste streams, we are talking about a few thousand tons of gallium per year. We produce more gold every year than there is practically available gallium. Unfortunately this is the story with many proposed solutions to carbon capture. Many things are possible as a prototype which are completely infeasible at the industrial scales required to make a dent in atmospheric carbon because the resources don't exist to run chemistry at that scale.

evgen 5y ago
> The only reason [Gallium] is relatively inexpensive is that there is limited demand for the minuscule quantities that are currently produced. It is possible that we might be able to find more if we actively start looking for it? This would not be the first time that what was once a waste product becomes valuable once we know how to use it. Regarding gallium itself, its presence as basically waste product in bauxite ore suggests we can increase production (https://www.sciencedirect.com/science/article/abs/pii/S0301420715001233 https://www.sciencedirect.com/science/article/abs/pii/S03014...) and there may be other sources if we start searching.
- jandrewrogers 5y ago
  Gallium is found everywhere, it doesn't make sense to actively search for it because it doesn't concentrate anywhere. That's the whole problem. There is little that distinguishes bauxite ore from my backyard in terms of the amount of gallium that can be extracted. The advantage of extracting it from certain ore waste streams is two-fold even though they don't contain much gallium. First, the chemical processing cost varies with the chemistry of the rocks you extract the gallium from, and certain types of ore waste such as bauxite, zinc, etc are cheaper to deal with. Second, these rocks have already been dug out of the ground as part of a mining operation, which is much cheaper than strip mining an arbitrary place to extract the same trace quantities of gallium -- you get to free-ride on the extraction costs of the primary mineral someone already paid for. If it doesn't matter where you dig, then all you can really optimize for is the processing cost of where someone already dug. It would make no sense to increase bauxite production for the purpose of gallium production. Extracting gallium from bauxite is only economical to the extent that there is healthy demand for the aluminum produced from that bauxite. This is common in mining operations -- a secondary mineral that cannot be economically mined by itself becomes profitably extractable from the same ore if and only if the primary mineral is sufficiently profitable. Many less common metals are produced solely via secondary extraction because they cannot be profitably mined directly even when they concentrate.
  - merb 5y ago
    wouldn't it also increase tailings thus we would just change our pollution problem from co2 to toxic mining waste? I mean aren't tailings from bauxite highly toxic?
    - redprince 5y ago
      The tailings from the Bayer process for extracting aluminium oxide from bauxite aren't toxic. The remains ("red mud") have an elevated pH from the residual sodium hydroxide used in the extraction of the ore but that's about it. There's a lot of it though and that sheer amount makes it a bit of an environmental problem as Red Mud has limited industrial use and much of it will be dumped / stored somewhere.
    - jandrewrogers 5y ago
      No, bauxite processing is pretty benign. Strong hydroxides are used to extract the aluminum. Conveniently, a fraction of the gallium in the ore also leaches into the same hydroxide solution, so you can extract it by processing the waste solution after the aluminum has been precipitated. Any ore that uses strong alkali extraction is a candidate for cheap gallium extraction. Bauxite processing produces iron, silicate, and similar minerals. Nothing anyone would identify as toxic. The alkali hydroxide solutions are recycled because they are one of the most expensive inputs. Nothing to worry about as such things go.
      - hilbert42 5y ago
        Right, but it's fair to say the real pollution from bauxite comes from the production of aluminum. It's often said that aluminum is solid electricity and if the electricity used to produce it comes from coal then its production is polluting, if from clean energy then it isn't (well, at least it's minimal).
bitwize 5y ago
Yeah, basically there's only one solution to the CO2 problem that's also the solution with the least political will to push it through: deindustrialization. Everything else relies on miracles and/or unobtainium.
- exporectomy 5y ago
  The implication of that is that we should accept climate change, is that what you're saying? Deindustrialization would probably be worse than climate change so it's likely not an option. In case you want deindustrialization, can you estimate it consequences in terms of deaths caused or some other important metric so we can compare it to climate change?
  - andy_ppp 5y ago
    I think we could do the following; local seasonal food farmed as naturally as possible. It’s likely to still use some carbon, but doing this would massively reduce what’s used today. Tax meat production heavily. Tax air travel heavily and these taxes should increase exponentially per journey per person. Stop shipping goods half way around the world… make the things you need locally. Improve the grid and invest in plans for heating using electricity. Build hundreds of small nuclear plants. I think that’s net zero roughly but it’s not possible politically even though it’s a feasible solution to the problem.
    - zarzavat 5y ago
      This is the conventional wisdom, but as you mention it's not politically possible. It would be hard for one country to enact all of these changes, let alone all the world's countries. There is an alternative path and that is radical renewable energy production. Many of the things you mention are not intrinsically harmful, they are only harmful because of the dependency on fossil fuels. For example, shipping things around the world is not intrinsically harmful, it is only harmful because it today requires fossil fuels. From this perspective the actual problem is a shortage of renewable energy. If we build vastly more renewable energy capacity then we can make fossil fuels economically unviable. Since that is a problem of money rather than politics it is much more viable as a solution.

evgen 5y ago

> The only reason [Gallium] is relatively inexpensive is that there is limited demand for the minuscule quantities that are currently produced. It is possible that we might be able to find more if we actively start looking for it? This would not be the first time that what was once a waste product becomes valuable once we know how to use it. Regarding gallium itself, its presence as basically waste product in bauxite ore suggests we can increase production (https://www.sciencedirect.com/science/article/abs/pii/S0301420715001233 https://www.sciencedirect.com/science/article/abs/pii/S03014...) and there may be other sources if we start searching.

jandrewrogers 5y ago
Gallium is found everywhere, it doesn't make sense to actively search for it because it doesn't concentrate anywhere. That's the whole problem. There is little that distinguishes bauxite ore from my backyard in terms of the amount of gallium that can be extracted. The advantage of extracting it from certain ore waste streams is two-fold even though they don't contain much gallium. First, the chemical processing cost varies with the chemistry of the rocks you extract the gallium from, and certain types of ore waste such as bauxite, zinc, etc are cheaper to deal with. Second, these rocks have already been dug out of the ground as part of a mining operation, which is much cheaper than strip mining an arbitrary place to extract the same trace quantities of gallium -- you get to free-ride on the extraction costs of the primary mineral someone already paid for. If it doesn't matter where you dig, then all you can really optimize for is the processing cost of where someone already dug. It would make no sense to increase bauxite production for the purpose of gallium production. Extracting gallium from bauxite is only economical to the extent that there is healthy demand for the aluminum produced from that bauxite. This is common in mining operations -- a secondary mineral that cannot be economically mined by itself becomes profitably extractable from the same ore if and only if the primary mineral is sufficiently profitable. Many less common metals are produced solely via secondary extraction because they cannot be profitably mined directly even when they concentrate.
- merb 5y ago
  wouldn't it also increase tailings thus we would just change our pollution problem from co2 to toxic mining waste? I mean aren't tailings from bauxite highly toxic?
  - redprince 5y ago
    The tailings from the Bayer process for extracting aluminium oxide from bauxite aren't toxic. The remains ("red mud") have an elevated pH from the residual sodium hydroxide used in the extraction of the ore but that's about it. There's a lot of it though and that sheer amount makes it a bit of an environmental problem as Red Mud has limited industrial use and much of it will be dumped / stored somewhere.
  - jandrewrogers 5y ago
    No, bauxite processing is pretty benign. Strong hydroxides are used to extract the aluminum. Conveniently, a fraction of the gallium in the ore also leaches into the same hydroxide solution, so you can extract it by processing the waste solution after the aluminum has been precipitated. Any ore that uses strong alkali extraction is a candidate for cheap gallium extraction. Bauxite processing produces iron, silicate, and similar minerals. Nothing anyone would identify as toxic. The alkali hydroxide solutions are recycled because they are one of the most expensive inputs. Nothing to worry about as such things go.
    - hilbert42 5y ago
      Right, but it's fair to say the real pollution from bauxite comes from the production of aluminum. It's often said that aluminum is solid electricity and if the electricity used to produce it comes from coal then its production is polluting, if from clean energy then it isn't (well, at least it's minimal).

bitwize 5y ago

Yeah, basically there's only one solution to the CO2 problem that's also the solution with the least political will to push it through: deindustrialization. Everything else relies on miracles and/or unobtainium.

exporectomy 5y ago
The implication of that is that we should accept climate change, is that what you're saying? Deindustrialization would probably be worse than climate change so it's likely not an option. In case you want deindustrialization, can you estimate it consequences in terms of deaths caused or some other important metric so we can compare it to climate change?
- andy_ppp 5y ago
  I think we could do the following; local seasonal food farmed as naturally as possible. It’s likely to still use some carbon, but doing this would massively reduce what’s used today. Tax meat production heavily. Tax air travel heavily and these taxes should increase exponentially per journey per person. Stop shipping goods half way around the world… make the things you need locally. Improve the grid and invest in plans for heating using electricity. Build hundreds of small nuclear plants. I think that’s net zero roughly but it’s not possible politically even though it’s a feasible solution to the problem.
  - zarzavat 5y ago
    This is the conventional wisdom, but as you mention it's not politically possible. It would be hard for one country to enact all of these changes, let alone all the world's countries. There is an alternative path and that is radical renewable energy production. Many of the things you mention are not intrinsically harmful, they are only harmful because of the dependency on fossil fuels. For example, shipping things around the world is not intrinsically harmful, it is only harmful because it today requires fossil fuels. From this perspective the actual problem is a shortage of renewable energy. If we build vastly more renewable energy capacity then we can make fossil fuels economically unviable. Since that is a problem of money rather than politics it is much more viable as a solution.