Preparation of ultrafine TiO₂ powders by interfacial stripping precipitation method

Ultrafine TiO₂ powers with high purity, small size and uniformity was prepared through interfacial stripping precipitation method. Ti(IV) was extracted from P204-CCl₄/TiO(NO₃)₂ system with P204 as an extractant and ammonia aqueous solution as a re-extractant. The preparation process was optimized by controlling the preparation parameters (such as calcianated temperature and operation conditions). The result shows that the particle size and crystal grain diameter of ultrafine-TiO₂ particles are distinctly influenced by the calcinating temperature of TiO₂ sample and re-extraction modes, concentration of ammonia aqueous and temperature and ageing time. The optimum calcinating temperature of TiO₂ is 350°C. The optimum temperature and the optimum concentration of ammonia aqueous are 17.5°C and 1:5 respectively. Mixing oil in ammonia is beneficial to obtaining smaller and more uniform TiO₂ particles.