Effect of Initial Temperature on Iron Nugget Formation in Fluxless Processing of Titanomagnetite Under Isothermal – Temperature Gradient Profiles

Recently, the titanomagnetite by coal producing iron nugget under isothermal – temperature gradient profile is introduced. The reduction process is divided into three stages where in the first stage the initial temperature is kept constant for a certain of time and then the temperature is increased to 1380°C with a certain heating rate in the second stage and finally in the third stage the temperature is maintained at 1380°C for a certain time. The results of the experiments show that the initial temperature in the first stage affects the formation of iron nuggets. Initial temperatures of 700 to 1100°C produce many nuggets up to 3 mm in size, initial temperature of 1200°C produces one nugget with a size of about 4 mm and the initial temperatures of 1300 and 1380°C do not produce nuggets. Optimal iron recovery is achieved at an initial temperature of 1000°C. The slag contains titanium oxide, armalcolite and rest of metallic iron with a size of less than 0.5 mm. The nugget formation is believed due to the aggregation and agglomeration of iron particle during the increasing temperature from initial stage to 1380°C.