| 摘要 |
FIELD: chemical industry. SUBSTANCE: claimed invention describes process for preparing highly pure magnesium oxide from raw material comprising large amount of silicon compounds. This process is economical and ecologically pure. Claimed process for preparing magnesium oxide from natural raw material comprises dissolving it in mineral acid, separating undissolved residue from solution, purifying the solution from impurity metals, depositing magnesium containing compound and subsequently heat treating it. Mineral acid is sulfuric acid having concentration of at least 20 wt%. The undissolved residue is separated from the solution by cooling the mixture formed at raw material dissolution stage till crystallization state followed by washing said mixture with water. The solution is cleared from impurity metals by depositing the latter as hydroxides at pH of 5-7 and separating the resulting precipitate from the solution. Magnesium-containing compound is deposited as magnesium hydroxide at pH of 10-12, and heat treatment is carried out in two steps at temperatures from 450 to 850 C, and the resulting product is thereafter washed with water. EFFECT: more efficient preparation process. |
