Abstract: The process flow，reaction process，and the equipment of two kinds of acidolysis techniques applied in industrial production of titanium dioxide by sulfuric acid process（continuous acidolysis and intermittent acidolysis） were compared. Continuous acidolysis is characterized by high acid decomposition rate（more than 96%），low acid consumption，high degree automation，small equipment occupation area，little emissions，and high waste acid recovery.Its advantages in environmental aspects，such as continuous emission of acidolysis tail gas，low sulphur content，and easy to dispose，were reviewed；furthermore，when the waste acid was concentrated to 60%，it can be returned to acidolysis process，and the waste acid reuse rate could reach 100%.Problems and solutions were illustrated in energy consumption and equipment corrosion.Titanium slag continuous acidolysis technique has wide prospect in TiO2 production by sulfuric acid process.

Key words: continuous acidolysis, titanium dioxide, intermittent acidolysis