Study of MgO Production Possibility from Iraqi Dolomite

Abstract

A three-process approach was applied to extract MgO from Iraqi Dolomite. First process comprises leaching of -2mm Dolomite in 25% solid by 22% HCl, 10 minutes at room temperature. The second process is a separation includes two-steps, hydration and carbonation to separate Calcium as (PCC, 1st stage), 90.1% purity. Hydration was carried out, adding by 55% of weight calcined Dolomite to leached Dolomite at 70°C, 60 minutes; followed by carbonation with CO2 gas at 2 bars pressure, for 100 minutes at room temperature. The MgCl2 produced evaporated to precipitate the Calcium as (PCC, 2nd stage), 97% purity. The purified brine further was evaporated till dry salt MgCl2.6H2O (Bischofite) was obtained, then subjected for pyrohydrolysis (3th process) at 650oC, 60 minutes. HCl of 22% concentration was regenerated altogether with MgO of 95.48% purity after washing with water and drying.