SELECTIVE SEPARATION OF MAGNESIUM FROM OLIVINE MINERALS

The aim of this investigation was the selective separation of Mg(II) f rom olivine, (Mg,Fe)SiO4. The feasibility of leaching of Mg2+, Fe2+, a nd Fe3+ from olivine and serpentinized olivine with HCl or H2SO4 solut ions of pH similar to 2 or 3.5 has been examined. The results obtained showed that, under identical conditions, HCl solution is more effecti ve than H2SO4 in leaching of Mg2+ as well as Fe2+, and that the optimu m pH is <3.5. Magnesium ions are selectively and quite effectively sep arated from the leaching solution by precipitation of Mg(OH)(2) at pH similar to 11.5 since most, if not all, other metal ions that exist in natural samples are pre-precipitated as hydroxides and separated by f ilteration. Alternatively, Mg2+ is selectively separated from the leac hing solution by flotation as magnesium oleate in the 7.0-8.5 pH range .