Resource utilization of microcrystalline magnesite: Synthesis of magnesium oxide by malic acid steam-assisted decomposition method for the synergetic adsorption of Congo red dye and Cu(II) ion.

Microcrystalline magnesite, a rich raw mineral material, has been used to prepare magnesium-based adsorbents for the removal of dyes and heavy metal ions. Here, MgO adsorbent with well-developed edges, high surface area (96 mg·g) and abundant mesopores is prepared by malic acid steam-assisted decomposition method using light-burned MgO with a loose and porous structure as raw materials. Compared to the industrial light-burned MgO with dense structure, the malic acid steam can easily enter the interior of loose block, which promotes the crosslinking effect of magnesium malic and enhances the crystal growth of MgO.