Method for reusing ferric trichloride corrosive liquid in gravure plate making

The invention relates to a method for reusing a ferric trichloride corrosive liquid in gravure plate making. The method comprises the following steps: (1) performing primary filtration: removing impurities and granules of a waste liquid by using security cotton; (2) performing carbon filtration: filtering filtrate after primary filtration through activated carbon; (3) performing an replacement reaction: adding reduced iron powder into the filtrate after carbon filtration with stirring, enabling the components to react for 15-30 minutes, stopping stirring, and leaving to deposit naturally, wherein the addition amount of the reduced iron powder is 3-5 times of copper ions in the waste liquid; (4) concentrating: in a depressurized or high-temperature evaporation mode, concentrating till the baume degree meets a production control standard; (5) oxidizing: adding hydrogen peroxide and concentrated hydrochloric acid into a concentrated liquid; (6) filtering: filtering an oxidized liquid again to obtain the ferric t