Complex sentence: Then it could be reinserted into the purifier, and reused and rejuvenated multiple times, until it was thoroughly sulphuretted, and then sent to the sulphuric acid works for a small profit.
Split into simpler sentences: Then it could be reinserted into the purifier, and reused and rejuvenated multiple times, until it was thoroughly embedded with sulfur. It could then be sold to the sulphuric acid works for a small profit.