Waste gas recycling system and application method in crude salt refining

The invention provides a waste gas recycling system and an application method thereof in crude brine refinement, the waste gas recycling system comprises a tail gas compressor, a primary absorption tank and a secondary absorption tank, the tail gas compressor is connected with a 99% caustic soda fused salt furnace natural gas combustion tail gas output pipe, the output end of the tail gas compressor is connected with a primary absorption tank input pipe, and the primary absorption tank input pipe leads to the bottom of the primary absorption tank; the upper part of the primary absorption tankis connected with a secondary absorption tank input pipe, the secondary absorption tank input pipe is communicated with the bottom of the secondary absorption tank, the upper part of the primary absorption tank is communicated with the bottom of the secondary absorption tank, the bottom of the primary absorption tank is connected with a crude brine circulating pump, and the output of the crude brine circulating pump is di