...molten...only for a moment...
8) The tank trains of molten sulfur(USA spelling of Sulphur), is only fluid at loading.
Sulfur, is heated to somewhere around 265°, where it flows easier than water, and if it spills, in small amounts, cools in 10 seconds.
So, if you load a tank car with molten sulfur, it begins to cool rapidly, and on a cross country trip, probably solidifies to the core.
Early on, the action of being in a non-baffled tanker, is that it sloshes back an forth in the tank, depending on how far from the top of the tank it's loaded.
At the delivery point, it is hooked up to a steam line of about 300°, 1000psi pressure...
After three days, the valve is opened slightly, and then the top bung is opened...the gasses inside the tank are retained inside, or else the worker could suffer terminal hazards of inhalation.
In situations of fire, sulfur oxides(So3,So4), can purge oxygen from the lungs.