采用钨丝网发热体对工业硅进行高温熔炼，通过在真空条件和低压条件下的对比试验，研究了不同压力条件对磷去除效果的影响。结果表明：在1×10^-3～2×10^-2Pa的真空条件下熔炼时，磷含量随熔炼时间的延长而降低并在熔炼前期下降迅速；磷的去除反应为一阶反应式，活化能为102kJ·mol^-，随熔炼温度的升高去除速率加快，2．7ks时去除率超过80％；在2～6Pa的低压条件下熔炼时，磷的去除反应也可以用一阶反应式表示，但磷的去除速率受温度影响不明显，去除速率常数受环境压力影响比真空条件下的低；不同压力条件下熔炼时磷去除速率的控制步骤不同。
Industrial silicon was smelt in high temperature by tungsten wire mesh heating unit and the effects of different pressure conditions on dephosphorization by contrast tests of vacuum and low pressure were studied. The results show that when melting was done under the vacuum of 1 X 10^-3 -- 2 X 10^-2 Pa, the content of phosphorus, which decreased quickly in early stage, decreased with melting time. The dephosphorization reaction was first-order kernel and the activation energy was 102 kJ · mol^-1. The removal rate, which increased with the increase of the melting temperature, exceeded 80% at 2. 7 ks. Under the low pressure of 2- 6 Pa, the dephosphorization reaction could be expressed by first-order kernel, but the effect of temperature on the removal rate of phosphorus was not obvious and the removal rate contant affected by pressure was low comparing with vacuum condition. The control step of dephosphorization rate under different pressures was different.
参考文献
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