Method of recovering sulfuric acid from the spent acid cleaning process of a semiconductor

The present invention discloses a method of recovering sulfuric acid from the spent acid cleaning process of a semiconductor, the method comprising the following steps: Step 1, to be placed in the catalyst chamber waste acid and heated to 80-100 deg.] C, to initiate the reaction, the catalyst chamber catalyst provided a catalyst to inert metal; step 2, was heated to 120-150 deg.] C, the reaction for 3-6 hours, to detect hydrogen peroxide in the spent acid content of less than 100 ppm; step 3, the spent acid was slowly cooled to 30-50 deg.] C; step 4, the spent acid is introduced into the photo reactor, complete decomposition of residual peroxide, to detect hydrogen peroxide in the spent acid content is less than 2ppm. Recycling method of the present invention provides a simple operation, the processing time is short, high efficiency, thorough treatment (hydrogen peroxide concentration falls below 2ppm), not into the other impurities, such that the spent acid can be utilized again, significantly reduced costs, It has a very good prospect.