A novel recirculating reactor for the leaching of magnesia by CO2

A novel slurry recirculating reactor was designed to selectively leach caustic-calcined magnesia into soluble magnesium bicarbonate with CO2 as the leaching reagent. Compared with the reactor without slurry recirculating, the leaching rate of magnesia could be enhanced by 80%–90% in this reactor. Parameters including mass concentration of the magnesia slurry, flowrate of slurry recirculating, injection rate of CO2 and temperature were studied with respect to their effects on the leaching kinetics. A fast leaching of caustic-calcined magnesia could be achieved with a high CO2-consuming efficiency of 65–70% in this reactor.