Sulfuric acid recovery device and method for recovering sulfuric acid

A sulfuric acid recovery device comprising:

• a first recovery tank configured to recover sulfuric acid;
• a concentration meter configured to measure a concentration of hydrogen peroxide contained in the sulfuric acid in the first recovery tank;
• a discharge pipe configured to discharge the sulfuric acid from the first recovery tank to a second recovery tank;
• a circulation pipe with a maximum installation height position set to be equal to or lower than a maximum installation height position of the discharge pipe and with a flow path formed, such that the sulfuric acid discharged from the first recovery tank returns to the first recovery tank;
• a first valve configured to open and close a flow path of the discharge pipe;
• a pump configured to feed the sulfuric acid discharged from the first recovery tank to at least the circulation pipe of the circulation pipe and the discharge pipe;
• and
• a control circuit configured to control opening and closing of the first valve in accordance with the concentration of the hydrogen peroxide measured by the concentration meter.