| 摘要 |
A method for making solar grade silicon from metallurgical grade silicon is disclosed, which including, treating a calcium-silicate based slag by molten calcium-silicate based slag in a first vessel, whereby phosphorous in the calcium-silicate based slag is transferred to the ferrosilicon alloy producing a calcium-silicate based containing less than 3 ppmw phosphorous; obtaining the calcium-silicate based slag containing less than 3 ppmw phosphorous from the first vessel; treating a molten metallurgical grade silicon in a second vessel with the calcium-silicate based slag containing less than 3 ppmw phosphorous to reduce the content of phosphorous, boron and iron in the metallurgical grade silicon; and removing solar grade silicon with low content of phosphorous, boron and iron from the second vessel.
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