| 摘要 |
<p>Preparation of Al2O3 by digestion of bauxite, in aqueous solution, with a strong base and heating, separating the insoluble impurities and recovery of Al2O3 3H2O from the solution; at least 0.1% (or impurities) of a mixture of starch and an acrylic polymer (in the proportions of 10:1 to 200:1) to the digested mixture. The polymer has molecular weight at least 50,000 and at least 80% of its units are acrylic acid or its salts. Prepared are polyacrylic acid and sodium polyacrylate but co-polymers of these with other double bond monomers may be used. The process gives efficient removal of impurities for the Al2O3.</p> |
