Adds a recipe for turning Sulphuric Acid into Sulphur, using coal as a reducing agent. It's not entirely chemically sound, but it should be close enough to skirt by.

The recipe costs 60 Sulphuric Acid, 1 Coal and 100 Water, producing 5 Sulphur over 1.5 seconds. It's effectively the reverse of the recipe for producing Sulphuric Acid out of Sulphur, with a slight loss (.5s extra craft time, 10 more Sulphuric Acid cost).

This might be pointless, but it just bugged me how I had all this Sulphuric Acid and still had to go through Coal Liquefaction to make basic Sulphur that I can dig out of the ground anywhere on Vulcanus.