Preparation method of high-purity sulfur gas serving as reducing gas

The invention discloses a preparation method of a high-purity sulfur gas serving as a reducing gas. The preparation method comprises the following steps: carrying out melting, filtration, atomization, gasification, ejecting and the like to finally obtain the high-temperature sulfur gas serving as a reducing agent. The high-temperature sulfur gas can be used for chemically decomposing portland cement serving as a byproduct of sulphuric acid preparation from gypsum and recovering sulfate ores, industrial waste residues of sulfate and the like. The preparation method has the advantages of simpleness in process, rapidness in growth speed, capability of continuous production and the like. In addition, according to the preparation method disclosed by the invention, the mole fraction of the components of the sulfur gas can be regulated between 5 percent to 100 percent by adding inert atmosphere, and the needs for different material reduction reactions of a subsequent device are met.