EFFECT OF LIMESTONE ADDITION ON DIRECT REDUCTION OF COMPOSITE PELLET MIXTURE OF IRON OXIDE AND COAL

• Main Author: BUANA (NIM : 12508023), PONDRA
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/23680
• Institution: Institut Teknologi Bandung

Steel is one of the main materials used in human life. The main raw material for steelmaking is iron. Fine grained iron ores are generally come through iron ore <br /> <br /> <br /> <br /> agglomeration process before being used as feed in the reduction process. One example of agglomeration process is pellet manufacturing. Composite pellet is a mixture of iron ore and coal, and used as feed in the iron-making process using Rotary Hearth Furnace technology. <br /> <br /> <br /> <br /> Previous studies reported that the addition of alkali-carbonate elements can increase iron ore reducibility. Therefore, in this research direct reduction of iron <br /> <br /> <br /> <br /> ore pellets with addition of limestone is conducted. <br /> <br /> <br /> <br /> Steps of experiments in this study including raw materials preparation and pellets manufacturing, pellet reduction, and chemical analysis to determine metallic iron content. During the reduction process, various condition were applied: various limestone additions (0.0%, 2.5%, 5.0%, and 7.5%), heating temperature (800 ° C, 1000 ° C and 1200 ° C), and heating time (20, 40, 60, 90, and 120 min). A total of 60 pieces of reduction pellets were produced. The results of the study showed that the effect of limestone addition to pellets have particular effect to certain temperature. At temperatures of 800 ° C, the addition of limestone has no significant effect on the pellet. At temperatures of <br /> <br /> <br /> <br /> 1000 ° C, the addition of limestone as much as 5% weight percent metallization deliver good value. At temperatures of 1200 ° C, the addition of 5% limestone <br /> <br /> <br /> <br /> give the best value of rate constant. However, the addition of limestone as much as 5 % and 7,5 % could increase the possibility of slag formed which lower the <br /> <br /> <br /> <br /> reducibility of iron oxide and also percent metallization of sponge iron decreased.