Patent ID: 7897137

Claim:
A method for producing high-active titanium dioxide anatase hydrosol by using metatitanate as precursor, comprising the steps of: (1) adding water into the metatitanate and mixing uniformly to obtain a suspension; adding an alkali solution into the suspension to adjust pH value to be 7 to 13 to obtain an adjusted composition; stirring uniformly the adjusted composition at 10 to 40° C. to obtain a treated suspension; filtering the treated suspension to get a filter cake; washing the filter cake to remove sulfate ions; repeating the above steps one to three times; and adding water to wash the filter cake until the pH value is near to neutral; (2) adding water into the filter cake and mixing uniformly to obtain a watered composition; adding an acid solution into the watered composition to adjust pH value to be between 0.1 and 3.0 to obtain another adjusted composition; and stirring uniformly the another adjusted composition to obtain a uniform suspension; (3) peptizing the uniform suspension obtained in said step (2) according to one of the following methods (a), (b), and (c): (a) dispersing the uniform suspension for 3 to 60 hours while keep heating at 40 to 95° C. under stirring continuously to obtain the titanium dioxide anatase hydrosol; (b) dispersing the uniform suspension for 5-100 minutes to obtain a dispersed suspension, then heating the dispersed suspension for 0.5-40 hours under stirring continuously at 50 to 300° C. and under a pressure of 10 5 -5×10 6 Pa to obtain the titanium dioxide anatase hydrosol; (c) dispersing the uniform suspension for 5 to 100 minutes to obtain a dispersed suspension, then heating the dispersed suspension under stirring continuously at 50 to 2000 W microwave power for 2 to 20 hours to obtain the titanium dioxide anatase hydrosol.