Boron magnesium-containing impurities

However, the reduction reactions in which a solid reducing agent is used usually give impure products. In this case, the product contains 80% to 95% boron that also contains magnesium and boron oxide as impurities. The boron produced in this way is a brownish-black form having a density of 2.37 g/cm3. 

High purity magnesium containing both less than 0.02% by weight of impurities other than calcium and less than 10 ppm (parts per million) of boron. 

Boron prepared in this way contains magnesium and oxides of boron as impurities, and the purity ranges from 80% to 95% when the preceding procedure is used. The boron produced... 

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