Production method for improving gas concentration of SO2 in device for preparing sulfuric acid from ardealite

The invention relates to a production method for improving the gas concentration of SO2 in a device for preparing sulfuric acid from ardealite. The production method comprises the following steps: raw materials enter a suspension preheater and exchange heat with kiln gas separated from the tail of a firing kiln in the suspension preheater; after the raw material is heated to 700-1000 DEG C through heat exchange, a solid phase enters the tail of the decomposition kiln, and the raw material is heated in a suspension preheater; the kiln gas exchanges heat with the raw material in the suspension preheater for cooling, and takes away water in the raw material; after the raw material enters a decomposition kiln, gradually heating to 1150-1200 DEG C to finish the first two steps of reduction reaction, and enabling a solid phase to enter a firing kiln; carrying out mineralization reaction on the solid phase in a firing kiln at 1200-1450 DEG C to generate cement clinker; after the gas phase of the firing kiln reaches