Analysis of Factors Affecting the Whiteness of Titanium Dioxide

Taking the original and final titanium dioxide products from a titanium dioxide factory in 2019 as the object,the influences of iron content and rutile TiO₂ content on the whiteness of the product were statistically analyzed.On this basis,samples of different whiteness with similar iron content and rutile TiO₂ content were selected to analyze the particle size distribution by a laser particle size analyzer and SEM,respectively.The results show that the whiteness of the product decreases with increase of the iron content,and a significant decrease of the whiteness can be found with the iron content exceeding 50 ppm.At 97% to 100% of the rutile TiO₂ content,the whiteness of the product shows a slight decrease with increase of the rutile TiO₂ content.With the increase of the product’s laser particle size D₅₀,the whiteness of the product shows a downward trend,and a higher whiteness can be obtained with D₅₀ less than 300 nm.At 200～300 nm of the average particle size by SEM,the product’s whiteness decreases with increase of the particle size,and the whiteness increases with increase of the ratio of particles of 150～350 nm.Hunter whiteness above 95 of the product can be obtained at the average particle size less than 240 nm and the proportion of particles of 150～350 nm above 75%.