| 摘要 |
Pure alumina (Al2O3) is recovered from alunite (Al2(SO4)3.K2SO4.4 Al (OH)3) which is found mixed with various impurities by first calcinating the alunite in the presence of a chloride to produce impure Al2O3 and other biproducts, and the impure Al2O3 is then contacted with concentrated HCl to produce, after concentration and crystallization, crystals of AlCl3.6H2O. These crystals are then calcinated to yield highly concentrated HCl and pure alumina. |
