Synthesis of high-purity zircon, zirconia, and silica nanopowders from local zircon sand

• Published in: Ceramics international Vol. 45; no. 6; pp. 6639 - 6647
• Main Authors: Musyarofah, Lestari, Novia Dwi, Nurlaila, Rizka, Muwwaqor, Nibras Fuadi, Triwikantoro, Pratapa, Suminar
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.04.2019
• Subjects: Amorphous silica; Cristobalite; Monoclinic zirconia; Nanopowder; Tetragonal zirconia; Zircon; Cristobalite; Nanopowder; Amorphous silica; Monoclinic zirconia; Zircon; Tetragonal zirconia
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2018.12.152

High-purity zircon (ZrSiO4) nanopowder was successfully produced from Indonesian natural zircon sand using a low-cost purification approach via magnetic separation, immersion in HCl, and reaction with NaOH, followed by a top-down nanosizing process using wet ball-milling for 10 h and annealing at 200 °C for 2 h. Furthermore, polymorph zirconia (ZrO2 – amorphous, tetragonal, and monoclinic) and silica (SiO2 – amorphous and cristobalite) nanopowders were also successfully derived from the purified zircon powder using a bottom-up method via alkali fusion and co-precipitation processes followed by calcination. The crystallite size of the powders was estimated from X-ray diffraction (XRD) data analysis to give 40, 31, 61, and 149 nm, respectively, for the zircon, tetragonal- and monoclinic-zirconia, and cristobalite. Microstructural characteristics of the zircon, silica, and zirconia nanopowders were revealed in transmission electron microscopy (TEM) images which confirmed that the average sizes of the particles were in a good agreement with the XRD estimated values.