METHOD OF PRODUCING ALUMINUM OXIDE AND CARBONATE FROM RICH AL MATERIALS WITH INTEGRATED COOPERATIVE CO₂ DISPOSITION

摘要

A process for alumina and carbonate production from aluminium rich materials with integrated CO2 utilization, comprising: comminuting and leaching Al-rich materials in concentrated HCl; separating unreacted material from metal chloride solution; separating Al3+ from solution by crystallization of AlCl3.6H2O; calcination of AlCl3.6H2O with HCl recovery; precipitation of metal carbonates from CO2; regeneration of HCl and extractive amines; the Al3+ separation the facilitated by increasing HCl concentration; the calcination being performed in two steps, one in the range 400 and 600° C. to generate a HCl-rich gas and one above 600° C. to produce Al2O3; for precipitating metal carbonates, mixing the metal chloride solution with an organic solution containing a selected amine and contacting the mixture with a CO2-containing gas, thereby also extracting HCl by formation of an ammonium chloride salt complex; processing thermally or chemically the organic solution to regenerate the amine for recirculation.