| 摘要 |
The present invention discloses a method for eliminating boron impurities in metallurgical silicon which includes the following steps: the metallurgical silicon powders being immersed in acid for 6~48 hours is then washed and heatingly dried; silicon powders being acid cleaned, washed and heated in the first step is heated to 300.degree.C ~ 700.degree.C in the reactor and fed in oxidizing gas for oxidation reaction, wherein the reaction time is 6~72 hour s. The Silicon powders being heatingly oxidized are immersed in water or acid for 1~6 hours and then washed clean; the silicon powders being immersed and washed is baked at 100.degree.C ~ 300.degree.C for 6~24 hours; whereas t he metallurgical silicon purification art of the present invention is done at lower temperature, the operation is easier while lowering down the purification co st to provide good material for next work steps thereby satisfying the demands for low cost solar grade polycrystalline silicon productions.
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