IN2014MN01026A - - Google Patents

Abstract

The invention relates to the pyrometallurgical processing of red mud. Red mud is melted in an oxy fuel skull melting unit iron is reduced with a carbon reducing agent and the metal and slag are discharged separately. The mud is additionally heated and dried in a drying device to a moisture content of 6 10% using heat from the melting unit flue gases having a temperature of 1750 1850°? with lime production waste in the amount of 3 6% of the mass of the mud being added to the wet red mud. The dried mud is fed using an airtight feeding device from the drying device into the melted slag which is heated to a temperature of 1640 1680°? at a rate of 1.2 1.4 tonnes to 1 m2 of the surface of the melted slag per hour. Iron is reduced from the melted furnace charge using carbon containing materials which are fed into the slag in an amount that ensures an iron oxide content of 3 5% in the reduced final slag. The separate discharge of the melting products is carried out continuously or intermittently with the fluctuations in the level of the melt in the melting unit being maintained at not more than 200 300 mm through the adjustment of the discharge rate and the amount of melting products. The result is a highly productive continuous single stage process for processing red mud and a simplification of the processing process.