- 著者
-
植田 和利
伊東 和彦
上原 誠一郎
佐藤 博樹
- 出版者
- 一般社団法人 日本科学教育学会
- 雑誌
- 科学教育研究 (ISSN:03864553)
- 巻号頁・発行日
- vol.40, no.1, pp.39-45, 2016
We produced a pure Si substance directly from a SiO<sub>2</sub>-Mg system using the solar furnace in the air. After the reagent of SiO<sub>2</sub>-Mg system was melting for 2–3 minutes under the solar furnace, Si grains (~1–3 mm) surrounded by forsterite (Mg<sub>2</sub>SiO<sub>4</sub>) were produced as the reaction product. From the phase diagram of MgO-SiO<sub>2</sub> system, it is considered that the reaction, 2 SiO<sub>2</sub> + 2 Mg → Si + Mg<sub>2</sub>SiO<sub>4</sub>, occurred. In this reaction, the existence of Mg<sub>2</sub>SiO<sub>4</sub> melt might have protected Si reduced from SiO<sub>2</sub> against O<sub>2</sub> in the air, and might have made Si grain grow larger in the melt. In the reduction of SiO<sub>2</sub> by Mg, we could have obtained Si grains visible to the naked eye within a few minutes under the solar furnace. Being a simple and short experiment this experiment is suitable for science students.