Materials and Methods of Fine silicon powder

For the magnesium reduction, we used SiO2 powder (99.99%) and pure magnesium (99.9%) purchased from US Research Nanomaterials, Inc. (Houston, TX, USA) as raw materials. Considering the molar masses in reaction (2), the reaction mass ratio of SiO2 to Mg is approximately 60:96. In this study, 20 g of SiO2 raw material powder was selected. Although the theoretical amount of Mg required to reduce this amount of SiO2 is 32 g, 200 g of Mg was used for the sufficient reduction reaction. The prepared SiO2 powder was placed with about 5 mm thickness on graphite trays (diameter 100 mm) and irregularly shaped Mg fragments of about 10 mm in size separately, finally covered with a graphite cap. The inner wall of the graphite tray containing SiO2 was painted and dried with a 10%-MgO ethanol solution to prevent the reaction between the reduced Si and carbon and then placed into a stainless-steel chamber. After reducing the pressure in the chamber to 7 Pa with a mechanical oil vacuum pump, argon gas of 99.999% purity (PS Chem Co. LTD, KOREA) was injected to reach atmospheric pressure, and the chamber was evacuated again. After repeating this process several times, the chamber was finally filled with argon gas at 1.1 × 105 Pa and then heated by 15 K/min to 1023 K, 1123 K, and 1223 K, respectively. The reduction reaction was carried out for 20 h at those temperatures, and then the chamber was cooled under the same atmosphere. The microstructures and phases of the obtained Si metal powder were evaluated using an oxygen-nitrogen hydrogen determinator (ELTRA ONH-P), Inductively Coupled Plasma Mass Spectrometer (ICP, Varian 820), scanning electron microscopy (SEM, TESCAN MIRA3-LM) and X-ray diffraction analysis, (40 kV 250 mA radiation, Cu Ka), (Rigaku International Corporation D/Max-2500), respectively. If you are looking for high quality, high purity and cost-effective Silicon powder, or if you require the latest price of Silicon powder, please feel free to email contact mis-asia.

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