| 摘要 |
PURPOSE:To produce highly pure Si, economically and efficiently, with a simplified means, by carrying out the complete reduction of a powdery mixture of SiO2 and a specific reducing agent instantaneously in a plasma gas stream. CONSTITUTION:1mol of powderly SiO2 (e.g. high purity quartz sand) crushed to about 200-325 mesh is added to a hot aqueous solution containing >=2mol of a reducing agent such as saccharose (in terms of C), kneaded homogeneously, dried, and pulverized to obtain powderly mixture of SiO2 and the reducing agent. The powder is thrown into the hopper 1, tansferred by H2 gas supplied to the feeder 2 attached to the bottom of the hopper 1, and introduced into the plasma torch 4 at the top of the reaction furnance 3. The powder is passed through the H2 gas plasma stream A of >=2,000 deg.C generated by the plasma torch 4, and is reduced completely and almost instantaneously to Si. The produced Si is cooled together with the gas stream with the cooler 5, separated from CO, H2 and stream by the separator 6, and delivered from the bottom of the separator 6.
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