What happens to sulfur during the roasting of tin ore?

During the tin processing of low-grade concentrates from complex ores, the ore is roasted in a reverberatory or multiple-hearth furnace at temperatures ranging from 550 to 650 °C (1,025 to 1,200 °F) specifically to drive off the sulfur. This roasting step is a critical preparation phase that precedes the smelting process, ensuring that unwanted impurities are removed to facilitate the efficient extraction of tin metal.1