3 ms·

I've said it before and I'll say it again. An iron oxide fire has a ton of energy but none of the designs or tests I've seen so far even remotely attempt to pr

I've said it before and I'll say it again. An iron oxide fire has a ton of energy but none of the designs or tests I've seen so far even remotely attempt to prepare for an accident. Gas? Shut it off. Wood and coal? Water. Oil? Fine water mist or co2. But iron oxide? An out of control fire can burn for days and most fire departments aren't equipped to handle it. The byproduct is a magma that destroys anything it touches and if water contacts an iron fire it will result in an explosion.

petertodd 6y ago
An iron oxide fire is not the same as thermite: burning iron still requires oxygen from the atmosphere, like any other fire. Thermite has its own oxidizer built-in. So I suspect a pile of iron dust wouldn't be that much different from any other combustible dust in terms of fire risk. None of the websites I can find mention iron as an example of a metal fire when talking about the dangers of using water on them. Metals like magnesium and lithium yes. But not iron: https://www.isystemsweb.com/metal-fires/ https://www.isystemsweb.com/metal-fires/ This source talks about the use of water firefighting at steel mills. That's not quite the same thing as powdered metal. But still illustrative: https://firesafeworld.com/fire-safety-in-iron-and-steel-industries-code-of-practice/ https://firesafeworld.com/fire-safety-in-iron-and-steel-indu... As you'd expect, water on hot metal will lead to steam explosions. But from the sounds of it, the simplest solution to that problem is keep your distance, and keep putting water on the fire until it overwhelms the heat capacity of the molten metal.
- yetihehe 6y ago
  > As you'd expect, water on hot metal will lead to steam explosions. Steam explosions which kick up more metal in air. But I think typical firefighting foam would easily help with that, much less water but still deprives fire of oxygen.
  - petertodd 6y ago
    You're quite right. But if the metal isn't chemically reacting with the water - and it doesn't look like molten iron does - that's not that bad. If you asked me to fight such a fire, I'd setup some unmanned nozzles, retreat, turn on the pumps slowly, and just wait it out. Probably will be an expensive total loss. But no-one gets hurt, and the burning iron doesn't itself release particularly toxic fumes, so no long term harm. Not that bad really for an industrial fire.

petertodd 6y ago

An iron oxide fire is not the same as thermite: burning iron still requires oxygen from the atmosphere, like any other fire. Thermite has its own oxidizer built-in. So I suspect a pile of iron dust wouldn't be that much different from any other combustible dust in terms of fire risk. None of the websites I can find mention iron as an example of a metal fire when talking about the dangers of using water on them. Metals like magnesium and lithium yes. But not iron: https://www.isystemsweb.com/metal-fires/ https://www.isystemsweb.com/metal-fires/ This source talks about the use of water firefighting at steel mills. That's not quite the same thing as powdered metal. But still illustrative: https://firesafeworld.com/fire-safety-in-iron-and-steel-industries-code-of-practice/ https://firesafeworld.com/fire-safety-in-iron-and-steel-indu... As you'd expect, water on hot metal will lead to steam explosions. But from the sounds of it, the simplest solution to that problem is keep your distance, and keep putting water on the fire until it overwhelms the heat capacity of the molten metal.

yetihehe 6y ago
> As you'd expect, water on hot metal will lead to steam explosions. Steam explosions which kick up more metal in air. But I think typical firefighting foam would easily help with that, much less water but still deprives fire of oxygen.
- petertodd 6y ago
  You're quite right. But if the metal isn't chemically reacting with the water - and it doesn't look like molten iron does - that's not that bad. If you asked me to fight such a fire, I'd setup some unmanned nozzles, retreat, turn on the pumps slowly, and just wait it out. Probably will be an expensive total loss. But no-one gets hurt, and the burning iron doesn't itself release particularly toxic fumes, so no long term harm. Not that bad really for an industrial fire.