Effect of Salt Treating Agent on Conversion Rate of Rutile for Titanium Dioxide Hydrate

Potassium hydroxide,phosphoric acid and zinc sulfate were separately or overall added to the titanium dioxide hydrated for calcination,and the rutile conversion rate of the samples after calcination was detected by Raman spectrometer.The results show that with increase in the addition of single potassium hydroxide or phosphoric acid,the inhibition effect on rutile conversion is stronger,and the inhibition is more obvious at lower temperatures.Furthermore,the conversion rate of rutile is more sensitive to the calcination temperature at higher addition amount of potassium hydroxide or phosphoric acid,while it is mainly determined by the temperature at higher calcination temperatures.Using zinc sulfate as the agent,the conversion rate of rutile increases with increase in the addition amount.When it is higher than 820 ℃,the temperature becomes the main factor for promoting the conversion of rutile.The orthogonal test results show that the influence order of the factors on rutile conversion is phosphoric acid＞zinc sulfate＞potassium hydroxide.A relationship between the conversion rate of rutile and addition amount of salt treating agent,calcination temperature,i.e.Y（Y≥97）=90.9+0.09X₁-5.30X₂+0.42X₃+0.009 6X₄,is established via the orthogonal tests.