Method for solidifying and stabilizing waste acid

A method for treating waste acid containing phosphoric acid and fluoroboric acid comprising steps of:

• condensing a waste acid containing phosphoric acid;
• adding barium hydroxide to another waste acid containing fluoroboric acid, mixing the waste acid containing fluoroboric acid with the condensed waste acid containing phosphoric acid to form a mixed waste acid, and dividing the mixed waste into two parts;
• dropping one part of the mixed waste acid in a stirrer which contained a first solidifying agent to form at least a granule;
• mixing the formed granule with another part of the mixed waste by stirring;
• and
• adding a second solidifying agent to the mixed waste by stirring, placing in stationary so that a solidified product of the mixed waste acid can be formed.

A method for treating waste acid containing phosphoric acid and fluoroboric acid comprising steps of:

• condensing a waste acid containing phosphoric acid;
• mixing the condensed waste acid containing phosphoric acid with a waste acid containing fluoroboric acid to form a mixed waste acid;
• adding barium hydroxide to the mixed waste acid and adjusting the pH of the mixed waste acid in acidic;
• adding a solidifying agent to the mixed waste acid so that a solidified product can be formed.