| 摘要 |
Al minerals such as kaolin, siliceous bauxite, kaolinitic clays, coal-bearing and other shales, or impure aluminas, which contain impurities like Fe, Ti, and Ca are treated for 0.5-5 hr with a recycled soln. near the b.p. contg. HC1 and a minor amt. of H2SO4, e.g., 20 and 5 %, resp., besides 1-3 % chlorides of Al and other metals to given a soln. contg. 8-9% Al2O3 as AlCl3 and an insol. residue that is washed. The acid soln. is then concd. up to the soly. limit of AlCl36H2O and treated with recycled 40-65% H2SO4 and with HC1 gas to obtain cryst. AlCl36H2O and a HC1/H2SO4 soln. of the impurities.
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