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How do you get an electric furnace hot enough to make various molten metals without all the heating equipment melting? Elon was saying that they would use hydr

How do you get an electric furnace hot enough to make various molten metals without all the heating equipment melting? Elon was saying that they would use hydrogen for carbon free high temperature metallurgy. Does this technology replace that?

baybal2 2y ago
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PaulHoule 2y ago
Already https://en.wikipedia.org/wiki/Induction_furnace https://en.wikipedia.org/wiki/Induction_furnace https://en.wikipedia.org/wiki/Electric_arc_furnace https://en.wikipedia.org/wiki/Electric_arc_furnace https://en.wikipedia.org/wiki/Zone_melting https://en.wikipedia.org/wiki/Zone_melting Their thing is a fancy version of the induction furnace. Also there is refractory and then there is refractory https://chemistry.fandom.com/wiki/List_of_elements_by_melting_point https://chemistry.fandom.com/wiki/List_of_elements_by_meltin... For instance Tungsten melts at 3407 °C, Platinum at 1772 °C, Iron at 1535 °C, Aluminum at 660 °C and there are all sorts of refractory oxides, carbides and nitrides so you can find something to make a vessel out of to hold most metals, if it is hard it is usually not the temperature but the chemical reactivity, e.g. Titanium wants to dissolve almost anything you try to melt it in which is more of a problem for keeping your Ti pure than it is maintaining the container's integrity. If you look in a chemistry book you'll see most metals can be reduced from oxide ores easily with hydrogen in the lab, the other reagent that commonly works is carbon monoxide, which is what is used in a blast furnace for reduction of iron. Another approach to "green" iron refining is to use carbon monoxide like a conventional blast furnace but capture the carbon dioxide in the exhaust and recycle it by cracking it down into carbon monoxide again.
- Animats 2y ago
  Good overview of a modern steel plant in Korea.[1] Useful for seeing how molten steel is handled at scale. Some good views of the refractory bricks inside a cold ladle. It's all about managed heat transfer, getting the heat out of the machinery before damage occurs. Water cooling of everything close to hot metal. Anybody doing "green" processing of ore at this scale yet? [1] https://www.youtube.com/watch?v=MfaqrVFnQBQ https://www.youtube.com/watch?v=MfaqrVFnQBQ
  - PaulHoule 2y ago
    Funny the technological breakthrough that made steel affordable was the recycling of heat in firebricks in https://en.wikipedia.org/wiki/Open-hearth_furnace https://en.wikipedia.org/wiki/Open-hearth_furnace invented by https://en.wikipedia.org/wiki/Carl_Wilhelm_Siemens https://en.wikipedia.org/wiki/Carl_Wilhelm_Siemens whose younger brother https://en.wikipedia.org/wiki/Werner_von_Siemens https://en.wikipedia.org/wiki/Werner_von_Siemens started the famous electrical equipment conglomerate. Previous to that the bit for a horse cost more than the horse and steel was expensive enough that a historical "sword" seemed more like a "knife" by our standards.
    - ggm 2y ago
      We were made to study this in numerical analysis classes. I regret not paying more attention, I failed the subject. The university was close to british steel, and so it made sense to the lecturer to use a subject he had some affinity to. Now, if they'd organised a tour of the steel plant...
jillesvangurp 2y ago
There are plenty of electrical high heat technologies available already. Mostly companies have stuck with gas mainly because it's cheap and avoided exploring alternatives for quite long for that reason. But there's plasma heating, arc furnaces, induction heating, infrared, resistive heating, heat pumps, etc. You can cover anything from thousands of degrees to (more commonly) hundreds of degree with these. Some steel plants already use arc furnaces or induction heating to melt the steel. I'm not sure where this technology sits but it all boils down to cost and effectiveness. If it works as advertised, companies will use it. The thing with green hydrogen is that you need even more electricity to generate it. Which makes some of these alternatives more economical because you can use the electricity directly at a higher efficiency.
- jabl 2y ago
  > Some steel plants already use arc furnaces or induction heating to melt the steel. Electric arc furnaces are used for around 30% of global steel production https://en.wikipedia.org/wiki/Steelmaking#/media/File:Evolution_convertisseurs.svg https://en.wikipedia.org/wiki/Steelmaking#/media/File:Evolut...
  - hnmullany 2y ago
    Electric arc furnaces use scrap steel as input - Nucor has been doing this in the US since the 70's. They don't reduce iron ore directly.

baybal2 2y ago

[dead]

PaulHoule 2y ago

Already https://en.wikipedia.org/wiki/Induction_furnace https://en.wikipedia.org/wiki/Induction_furnace https://en.wikipedia.org/wiki/Electric_arc_furnace https://en.wikipedia.org/wiki/Electric_arc_furnace https://en.wikipedia.org/wiki/Zone_melting https://en.wikipedia.org/wiki/Zone_melting Their thing is a fancy version of the induction furnace. Also there is refractory and then there is refractory https://chemistry.fandom.com/wiki/List_of_elements_by_melting_point https://chemistry.fandom.com/wiki/List_of_elements_by_meltin... For instance Tungsten melts at 3407 °C, Platinum at 1772 °C, Iron at 1535 °C, Aluminum at 660 °C and there are all sorts of refractory oxides, carbides and nitrides so you can find something to make a vessel out of to hold most metals, if it is hard it is usually not the temperature but the chemical reactivity, e.g. Titanium wants to dissolve almost anything you try to melt it in which is more of a problem for keeping your Ti pure than it is maintaining the container's integrity. If you look in a chemistry book you'll see most metals can be reduced from oxide ores easily with hydrogen in the lab, the other reagent that commonly works is carbon monoxide, which is what is used in a blast furnace for reduction of iron. Another approach to "green" iron refining is to use carbon monoxide like a conventional blast furnace but capture the carbon dioxide in the exhaust and recycle it by cracking it down into carbon monoxide again.

Animats 2y ago
Good overview of a modern steel plant in Korea.[1] Useful for seeing how molten steel is handled at scale. Some good views of the refractory bricks inside a cold ladle. It's all about managed heat transfer, getting the heat out of the machinery before damage occurs. Water cooling of everything close to hot metal. Anybody doing "green" processing of ore at this scale yet? [1] https://www.youtube.com/watch?v=MfaqrVFnQBQ https://www.youtube.com/watch?v=MfaqrVFnQBQ
- PaulHoule 2y ago
  Funny the technological breakthrough that made steel affordable was the recycling of heat in firebricks in https://en.wikipedia.org/wiki/Open-hearth_furnace https://en.wikipedia.org/wiki/Open-hearth_furnace invented by https://en.wikipedia.org/wiki/Carl_Wilhelm_Siemens https://en.wikipedia.org/wiki/Carl_Wilhelm_Siemens whose younger brother https://en.wikipedia.org/wiki/Werner_von_Siemens https://en.wikipedia.org/wiki/Werner_von_Siemens started the famous electrical equipment conglomerate. Previous to that the bit for a horse cost more than the horse and steel was expensive enough that a historical "sword" seemed more like a "knife" by our standards.
  - ggm 2y ago
    We were made to study this in numerical analysis classes. I regret not paying more attention, I failed the subject. The university was close to british steel, and so it made sense to the lecturer to use a subject he had some affinity to. Now, if they'd organised a tour of the steel plant...

jillesvangurp 2y ago

There are plenty of electrical high heat technologies available already. Mostly companies have stuck with gas mainly because it's cheap and avoided exploring alternatives for quite long for that reason. But there's plasma heating, arc furnaces, induction heating, infrared, resistive heating, heat pumps, etc. You can cover anything from thousands of degrees to (more commonly) hundreds of degree with these. Some steel plants already use arc furnaces or induction heating to melt the steel. I'm not sure where this technology sits but it all boils down to cost and effectiveness. If it works as advertised, companies will use it. The thing with green hydrogen is that you need even more electricity to generate it. Which makes some of these alternatives more economical because you can use the electricity directly at a higher efficiency.

jabl 2y ago
> Some steel plants already use arc furnaces or induction heating to melt the steel. Electric arc furnaces are used for around 30% of global steel production https://en.wikipedia.org/wiki/Steelmaking#/media/File:Evolution_convertisseurs.svg https://en.wikipedia.org/wiki/Steelmaking#/media/File:Evolut...
- hnmullany 2y ago
  Electric arc furnaces use scrap steel as input - Nucor has been doing this in the US since the 70's. They don't reduce iron ore directly.