Let’s say that an unlucky person is working on a factory that deals with molten metal. Pools of it. And that person manages to slip right into that molten, red-hot metal. How long would it take for that poor bastard to die? Would he dive into the “lava” or hit it like a hard surface? Would he feel excruciating amounts of pain?
Less than the amount of time Gollum floundered around in the lava.
Here’s a picture of a guy sitting on a pool of molten metal.
And it probably took years, maybe decades, to kill him.
More helpfully, I’ve heard that victims of very hot, fast burns often feel cold, since the nerve endings in the skin are so quickly destroyed. But it has the ring of “medical myth” to me, and I can’t find any confirmation in a quick search.
Whoa. Nature doesn’t like littering. That volcano looks pissed.
Molten steel is somewhere between 2600–2800ºF, depending on admixtures. Lava is cooler, between 540ºF on the low end, up to 2120ºF for magma lakes.
Keep in mind that there’s a big difference in the conductivity of materials. You can stick your hand in a pizza oven without the air turning it into a charcoal briquette, but a second of contact with the metal sides — which are nearly the same temperature — will give you a second-degree burn.
Some people in Pompeii died of “thermal shock” (i.e.: getting cooked alive) at peak temperatures of only about 500ºF. Granted, the case is a little different since the particulate ash was the medium of exposure, and in the case of falling onto molten steel, the Leidenfrost effect might protect the body for a second or so.
A modern crematorium operates at 1600–1800ºF, which is enough to reduce a body to ash and bone fragments. (I know this in intimate detail, having participated in the rites for two Japanese funerals so far. Everyone in attendance picks bones out of the ashes and places them in a container. There aren’t many bone fragments left bigger than a finger. The bone at the front of the skull seems to remain intact the best; a piece about the size of the palm of your hand remains.) Cremation takes about 1.5–2 hours for this, but keep in mind the properties of thermal transfer I mentioned earlier and realize that a furnace does this with an air temperature about 1000ºF lower than molten steel.
You probably wouldn’t feel anything since even the air would be hot enough to sear your nerve endings before you actually hit the steel. You might, just might, have enough time to attempt to scream before your lungs explode and your corpse starts burning. Not exactly a pleasant way to die, but relatively fast.
The guys on Mythbusters put their fingers into vessels of molten lead, and suffered no ill effects.
Well that didn’t take long.
[quote=“jtur88, post:9, topic:691751”]
The guys on Mythbusters put their fingers into vessels of molten lead, and suffered no ill effects.
[/QUOTE]Molten lead is a thousand degrees© cooler than molten steel. I imagine that makes quite a difference.
That escalated quickly.
How heavy (that is, how dense) is liquid steel?
If you tumbled into a vat of it, would you sink or float?
At room temperature, steel is at about 8 g/cm^3. It’ll expand a few percent at its melting point, but that won’t bring the density below around 7.5 g/cm^3. The human body is pretty close to the density of water at 1 g/cm^3, so you’ll definitely float for a short period before you vaporize.
Not quite the same thing as the OP but close, but I’ve done a fair amount of control system work in a few different steel mills. In one of them, they have huge ladles which carry a few hundred thousand pounds of molten steel from the blast furnace to other parts of the plant. The folks that worked there told me about one incident where one of the ladle’s mounts broke, causing it to tilt and dump most of its contents. There happened to be a guy under it at the time. They said the only good thing was that he was probably dead before he knew what hit him.
There are plenty of opportunities for the unlucky (or those who don’t like to follow safety precautions) to get themselves killed in steel mills. Most die from falls or get crushed by machinery. Getting killed by the steel itself is a lot less common.
A friend of mine recounts working in a place that handled molten nickel. Someone had been acting erratically and committed suicide by jumping into a vat of it. IIRC they quoted the temperature as over 600C, or about 1100F. The guy pretty much disappeared pretty fast; the forensic investigators rigged a ladle and pulled out some small pieces of bone. Nobody reported minutes of agonized screaming, anyway, but he didn’t want to get into detail. The weirdest thing he said was the guy left a man-shaped glowing red silhouette on the surface of the dark vat, like a bad road-runner cartoon.
Another fellow carelessly took a shortcut over a cooling ingot of the stuff (some giant 5x8 foot casting in a pit in the floor). He broke through, basically it burned off his legs and he had burns all over his body, but this might have been closer to 400C. He was in the hospital, I never heard whether he survived.
Generally, though, people have a healthy respect for molten metal and stay away from it.
Rule of thumb - rock is density 3, iron density about 6 - water density about 1. You’re not going to sink down into the stuff.
While spectacular, I don’t think this is a very good benchmark for what would happen to a person falling into a vat of molten steel. What they threw was a bag containing a bunch of small pieces of “camp waste.” As soon as the lava burns through the bag, it has access to a whole lot of surfacea area, so it can very rapidly heat the sundry items, resulting in commensurately rapid combustion/gas release.
In addition, the lava appears to have pretty high viscosity, making it difficult for the trash to float back up to the surface before being completely incinerated.
Additionally in addition, lava isn’t very dense. According to this PDF, its specific gravity is typically somewhere between 2.1 and 2.8 (compare with 1 for water, and 7.5 for steel).
Molten steel is much lower viscosity, and higher density. A person falling from a comparable height might submerge briefly, but would pop back up to the surface, buoyed to such a height that only about 13% of him would be submerged. The Leidenfrost effect would ensure that despite having been completely submerged at first, the parts that are now floating well above the surface would not be “wet” with a layer of molten steel; outgassing from the burning/boiling skin would ensure that molten steel would slide right off.
Not that this would matter. Being within a couple of feet of a large exposed surface of molten steel would ensure massive heat transfer via thermal radiation. Think of what happens when you put a lasagna within 6 inches of your oven’s broiler element, and you get the idea - except imagine that the broiler elemement, instead of being a skinny 1/4" wire at 1000F, is now a huge flat surface at 2500F. Radiative heat transfer scales to the fourth degree of absolute temperature, so in addition to the vastly larger radiative surface area, the per-unit-area thermal radiation coming off of the steel would be almost 17X as great.
Honestly, I think you would die very quickly because you would inhale the superheated air near the surface of the steel, searing your alveoli and rendering you unconscious/dead via anoxia (you may plan on holding your breath, but you will probably have the wind knocked out of you on impact, and after that you’ll probably be involuntarily screaming). That is, assuming the fall itself wasn’t fatal. People sometimes die (or are severely injured) by falling into water from great heights. Molten steel, being ~7.5 times as dense, would be expected to induce similar injuries from falls only 13% as high.
Did anyone else read this as “huge ladies?” 
Well, they’re not going to give the job of carrying that much molten steel to Sarah Jessica Parker.
Think of how much she could carry in her nose.