Synthesis of High-Purity Ceramic Nano-Powders Using Dissolution Method

Abstract

A set of ceramic powders has been synthesized using a “bottom-up” approach which is denoted here as the dissolution method. The raw materials were metal powders or minerals. The dissolution media were strong acid or base solutions. In the case of metallic raw materials, magnesium and titanium powders were sepa- rately dissolved in hydrochloric acid to obtain their precursors. They were then dried, washed, and calcined in air at various temperatures to produce pure MgO and TiO2 nano-powders. Pure MgTiO3 nano-powders by mixing the precursors at the stoichiometric ratio and calcining the dried mixture at a temperature as low as 700°C have also been successfully synthesized. In the mineral case, local zircon sand was used as the raw material. A standard procedure to extract the “clean” and pure zircon powder was applied which included washing, magnetic separation, and reac- tions using hydrochloric acid and sodium hydroxide. A pure zircon nano-powder was obtained by applying mechanical ball-milling to the zircon powder. The zircon powder was also chemically dissociated to give amorphous silica (SiO2), cristobalite, amorphous zirconia (ZrO2), and nanometric tetragonal zirconia powders.