PRODUCTION OF IRON SAND CONCENTRATE PELLETS WITH COAL BED REDUCTOR AND ADDITIVES NA2CO3 USING ISOTHERMAL - TEMPERATURE GRADIENT METHODS

• Main Author: Suryani, Indah
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/81229
• Institution: Institut Teknologi Bandung

Indonesia has iron sand deposit greater than the primary iron ore. Processing of iron sand to concentrate has been conducted in Indonesia. Currently, some plants are under construction in order to process iron sand concentrate into product of pig iron or sponge iron as stated in the decree of ministry for Energy and Mineral Resources No. 1 of 2014 either by using rotary kiln technology, RHF (rotary hearth furnace) and smelting reduction (HIsmelt). Reduction of iron sand concentrate for separating ferrous metal from titanium oxide was proposed by Sasabe in 1965 (US patent 3,218,152). Technique suggested by Sasabe is temperature gradient technique that iron sand concentrate pellet is heated gradually from room temperature up to 1350-1500°C. In this study, the method that was proposed by Sasabe is combined with isothermal which is so called isothermal – temperature gradient method. The use of isothermal and temperature gradients method as well as the effect of the addition of Na2CO3 into iron sand concentrate pellet are studied in this research. The research methodology starts with a characterization of the raw iron sand concentrate using XRD and XRF. Iron sand concentrate is then agglomerated into pellets with the addition of 2% bentonite and Na2CO3. The addition of Na2CO3 was varied from 1% to 5%. Pellets were dried for 24 hours, followed by reduction process. Reduction process uses isothermal temperature at 980oC for 30 minutes and it is followed by a temperature gradient toward the final temperature of 1180°C, 1230°C, 1280°C, 1330°C, and 1380oC for 1 hour. The final temperature was held for 10 minutes. After the reduction process, pellet was analysed by titration method to determine %Fe metal and X-ray mapping to observe the concentration of iron and titanium. Sponge iron products result from isothermal - temperature gradients method shows a hole in the middle of the product at temperature ?1330oC and the separation between the iron with impurities especially titanium, and reduction in volume. Titanium tends to be on the inside of the sponge iron. The final volume of the sponge iron experiences an average depreciation of 26.68% with the highest shringkage of 43.18% that occurs upon the addition of 4% Na2CO3 and the final temperature of 1380oC. The addition of Na2CO3 effects on the increasing of %metallization. The highest value of %Fe metal by the addition of 5% Na2CO3 is 73.54% with 83.22% total Fe.