PREPARATION OF MAGNESIA WITH LOW SILICA AND FERRIC OXIDE CONTENTS

摘要

PURPOSE: Provided is a preparation method of seawater magnesia with low silica and ferric oxide contents by reacting decarbonated seawater with effluent from steelmaking slag in stead of conventional slake lime-based emulsion. CONSTITUTION: Seawater magnesia is prepared by reacting slag effluents with decarbonated seawater to be pH10 or more to get Mg(OH)2 precipitates, washing, and sintering at 1000deg.C. The slag effluents are obtained by grinding slag to less than 45micrometer, adding water to be pH12 or more, aging over 10hrs, and filtering to remove Si and Fe precipitates such as Fe(OH)3 and (Si(OH)4)n, where the slag comprises CaO and SiO2 as main components, and MgO.