high quality whiteness,China national reference material,5 micron,D50=1.0um zirconium silicate is non-toxic, tasteless, white or offwhite powder, made of high-purity zircon sand and is a good-quality and cheap opacifier, whitening agent, stabilizing agent of ceramic glaze. zirconium silicate specification :ZrO2 65%min Fe2O3 0.10%max TiO2 0.09%max zirconium silicate Partical size D50 is 1.0um ...