| 摘要 |
<p>A method of obtaining alumina of high purity from aluminous mineral containing impurities in which the mineral is attacked with a sulphuric acid liquor followed by separation of a liquid phase from the resulting solid residue comprising (1) MIXING THE LIQUID PHASE WITH A LIQUOR CONTAINING HCl and H2SO4 at elevated temperature, (2) COOLING THE MIXTURE WITH THE PRECIPITATION OF HYDRATED ALUMINUM CHLOROSULPHATE HAVING THE FORMULA AlSO4Cl.6- 7H 2O, (3) separating the precipitate from the remaining liquor which contains the major part of the impurities in solution, (4) SUSPENDING THE SEPARATED PRECIPITATE IN A HYDROCHLORIC ACID LIQUOR, (5) CHLORINATING THE SUSPENSION BY INTRODUCTION OF GASEOUS HCl with precipitation of AlCl3.6H 2O, (6) separating the precipitated AlCl3.6H 2O, and (7) PYROLIZING THE SEPARATED PRECIPITATE TO PRODUCE ALUMINA OF HIGH PURITY AND GASEOUS HCl.</p> |
