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 AlCl3, and separating said precipitate from said liquid; and heating said precipitate under conditions effective for converting AlCl3 into Al2O3 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.

主权项

1. A process for preparing alumina, said process comprising:
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 AlCl3, and separating said precipitate from said liquid; heating said precipitate under conditions effective for converting AlCl3 into Al2O3 and producing gaseous HCl, recycling said gaseous HCl so-produced by contacting it with water so as to obtain a composition having a concentration of about 25 to about 45 weight and using said composition for leaching said aluminum-containing material.