Method for preparing gas-phase hydrogen chloride by utilizing chlorosilane residue

The invention discloses a method for preparing gas-phase hydrogen chloride by utilizing chlorosilane residue and belongs to the field of polycrystalline silicon residue treatment. The method comprises the following steps: performing hydrolysis reaction on the chlorosilane residue under a high-concentration sulfuric acid atmosphere, wherein hydrogen chloride gas is difficult to dissolve in liquid and can volatilize under the water absorption effect of the sulfuric acid; guiding the hydrogen chloride gas, the hydrogen generated from hydrolysis reaction and vaporized chlorosilane residue into a condenser and a high-pressure separator in turn; and treating and then separating, thereby acquiring a hydrogen chloride product. According to the invention, the production process is simple and reasonable, the resource utilization problem of the chlorosilane residue can be solved and the hydrogen chloride can be effectively recycled.