Method for recovering high-purity sulfuric acid from 2,4,6-trinitrotoluene nitrification waste acid, and application thereof

The invention relates to a method for recovering high-purity sulfuric acid from 2,4,6-trinitrotoluene nitrification waste acid, and an application thereof. According to the invention, TNT nitrification waste acid is subjected to staged rectification by using a filling material rectification tower. The method comprises the steps that: in a first stage, the TNT nitrification waste acid is subjected to heating and rectification under normal temperature by using the filling material rectification tower, such that water and most of organic impurities in the waste sulfuric acid are separated and removed; in the second stage, rest waste sulfuric acid is subjected to reduced-pressure rectification in the filling material rectification tower, such that residual organic impurities in waste sulfuric acid are further separated and removed, such that concentration and purity of sulfuric acid are improved, and high-purity sulfuric acid is obtained. Specific steps are shown in the specification. The method and the application provided by the invention have the advantages that: the process flow is simple, the cost is low, product quality is good, 98% high-purity sulfuric acid can be directly obtained, and a sulfuric acid recovery rate reaches 90%. The recovered sulfuric acid can be reused in the TNT nitrification process. Therefore, source recovery and environment protection are realized simultaneously. The method and application provided by the invention can be used in recovery treatment of 2,4,6-trinitrotoluene nitrification waste acid, and can be used in recovery treatments of waste sulfuric acid containing other organics such as nitrobenzene and nitrochlorobenzene.