Three forms of titanium dioxide

Titanium dioxide has three crystalline forms in nature: rutile, anatase and titanium plates.
Titanium plate is orthorhombic, crystal form is unstable, i.e. at above 650 ℃ into rutile, therefore no practical value industrially. Anatase is stable at room

temperature, but at high temperatures would like rutile conversion. Depending on the manufacturing method and transformed intensity during calcination is added with

inhibit or promote the like conditions. Generally considered less at 165 ℃ for almost no crystal transformation, more than 730 ℃ when the conversion quickly. Rutile

titanium dioxide is the most stable crystalline form, compact structure, as compared with anatase with high hardness, density, dielectric constant and refractive

index. Rutile and anatase are tetragonal system, but have different lattice, and thus the X-ray images are also different, anatase type io2 anatase in the

diffraction angle of 25.5 °, a diffraction angle in rutile 27.5 °. Rutile crystal slender, prism, usually twinning; while anatase approximate regular octahedral

general.