Abstract

Al–Si solvent refining is a promising process for silicon purification, and the key impurity elements are boron and phosphorus. Thermodynamic calculation and experiments in particular temperatures show that boron and phosphorus segregation coefficients in Al–Si melt decrease with decreasing temperature, and it is not verified in traditional solidification. In order to character boron and phosphorus removal in Al–Si solidification over a temperature range, high purity hypereutectic Al–Si melts were solidified at relatively low cooling rate. It is found that boron and phosphorus removal rates increase with decreasing temperature. The tread that the boron and phosphorus segregation coefficients in the Al–Si melt decease with decreasing temperature is confirmed in solidification over a temperature range. In addition, aluminum content in purified silicon is close to the maximum solid solubility of aluminum in silicon.

Graphic Abstract

Removal rates of boron and phosphorus after solidification of high purity hypereutectic Al–Si melts

中文翻译：

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高纯度过共晶Al-Si凝固过程中的硼和磷去除

摘要

Al-Si溶剂精制是一种有前途的硅提纯工艺，主要的杂质元素是硼和磷。热力学计算和特定温度下的实验表明，Al-Si熔体中硼和磷的偏析系数会随温度的降低而降低，而传统的凝固方法并未对此进行验证。为了表征在一定温度范围内的Al-Si固化中的硼和磷的去除，高纯度过共晶Al-Si熔体在相对较低的冷却速率下进行了固化。发现硼和磷的去除率随温度降低而增加。在温度范围内的凝固过程中，可以确定胎面中Al-Si熔体中硼和磷的偏析系数随温度降低而降低。此外，

图形摘要

高纯度过共晶Al-Si熔体凝固后硼和磷的去除率