Sulfur vulcanization sulfur is not miscible in the polymer prior to vulcanization and attention is paid to prevent sulfur bloom, where it migrates to the surface of the article. Accelerators act much like catalysts allowing vulcanisation to be performed cooler yet faster and with a more efficient use of sulfur. They achieve this by reacting with and breaking the sulfur ring to form a reactive intermediate, referred to as a sulfurating agent. This in turn reacts with cure sites in the rubber to bring about vulcanization. There are two major classes of vulcanization accelerators: primary accelerators and secondary accelerators (also known as
Claus process typically 240 °C for the second stage and 200 °C for the third stage (bottom bed temperatures). In the sulfur condenser, the process gas coming from the catalytic reactor is cooled to between 150 and 130 °C. The condensation heat is used to generate steam at the shell side of the condenser. Before storage, liquid sulfur streams from the process gas cooler, the sulfur condensers and from the final sulfur separator are routed to the degassing unit, where the gases (primarily HS) dissolved in the sulfur are removed. The tail gas from the Claus process still containing combustible components and