Abstract
Recently, several researches on red mud have been made from the point of view of recycling. It is one of the effective uses of red mud to recover such various elements as zirconium and titanium contained and to synthesize zeolites from the supernatant solution. In this study, the leaching of valuable components from red mud was in-vestigated using sulfuric acid as a function of leaching time, acid concentrations, and leaching temperatures. The results obtained are as follows; (1) The extraction of Na, Al, and Si amounts in equilibrium to 100, 70, and 65 percentages after ten minutes since the sodalite in red mud is very leachable. (2) Leaching of Fe and Ti in red mud is much affected by leaching temperatures, whereas leaching of Ca is little affected by leaching conditions. The extraction of Ca amounts to 20 percentages. (3) The leaching residue leached at 60°C for 64 hours using 1.8 mol/l of sulfuric acid contains TiO2 33.32 and ZrO2 2.45 percentages. TiO2 and ZrO2 in it are concentrated as compared with the original red mud. (4) The rate of process will be controlled by the surface reaction in the leaching process of Fe, Al, Ti, and Ca using sulfuric acid.
