Patents
The invention relates to a process for the recovery of refractory grade magnesia from marine bittern. The increased demand for high-purity magnesia as basic refractory has been prominent all over the world for two decades. The present process is based on the formation of magnesium chloride during the process of desulphation by the addition of stoichiometric quantity of calcium chloride to bittern. As a result, sulfate ions are removed in the form of gypsum which was filtered out. The desulphated bittern is again treated with stoichiometric amounts of ammonia and ammonium carbonate, thus forming magnesium carbonate. The purity of MgO is 99.3 %, and CaO/SiO2 ratio is also favourable. The process is not energy intensive and involves no boron removal steps. The high pure magnesia thus obtained in this process could be suitable for manufacturing high-quality magnesite bricks for our consuming industries.