We had to "freeze" some sulfur today, so we could pour a concrete wall in a trench.
Freeze sulfur? What does that mean?
Sulfur starts solidifying at around 240 degrees Fahrenheit. Regular cold water will rob the heat, the sulfur will solidify and - if it's seeping - the seep will stop.
We drained the trench first, which involved pumping a pit down below a drain, opening the drain and allowing the sulfur to leave the trench. We eventually reached the point where the constant seepage from slide plate valves was all that was adding sulfur, so we turned on the water hoses and "froze" the sulfur - after the steam to the loops was turned off.
It all worked as planned, although it took more time than I liked. After the sulfur was frozen, we cleaned the concrete, place the forms, placed some rebar and poured the concrete.
We'll leave the forms in place, until the next phase is complete, which is completely removing everything from the pit. This we won't do, since it's not part of our work. The temporary wall we poured today will allow the trenches to be used, without any uh-ohs. Trying to work in a pit with the possibility of sulfur pouring in is not pleasant thing to happen.
After the pit is empty of steam piping and equipment, we'll form and pour new concrete. When finished, the pit will be smaller, but good for another few dozen years - or longer.
This means I won't reek of sulfur for the next few days....that's a good thing.