PROCESSES FOR PREPARING ALUMINA AND VARIOUS OTHER PRODUCTS

摘要

There are provided processes for preparing alumina. These processes can comprise leaching an aluminum containing material with HCl so as to obtain a leachate comprising aluminum ions and a solid and separating said solid from said leachate; reacting said leachate with HCl so as to obtain a liquid and a precipitate comprising said aluminum ions in the form of AlCl and separating said precipitate from said liquid; and heating said precipitate under conditions effective for converting AlCl into AlO and optionally recovering gaseous HCl so produced. These processes can also be used for preparing various other products such as hematite MgO silica and oxides of various metals sulphates and chlorides of various metals as well as rare earth elements rare metals and aluminum.