Effect of pellet size addition on the selective reduction of limonite ore from Southeast Sulawesi

With the increasing demands of nickel in the world and the decreasing of nickel sulfide deposits, the processing of nickel laterite is the new challenge with selective reduction by using coal as reducing agent and Na2SO4 additives. This research aims to determine the preparation parameters of the pelletizing method before the reduction process in order to increase the content of the nickel in the reduction product. The samples were prepared by mixing limonite ore, coal, bentonite, and Na2SO4 additives, then continued by making the pellets with the variability of mass measurements of 5 grams, 10 grams and 15 grams. After the selective reduction, they were characterized by XRD to determine the formed phase, and an AAS test to determine the content after selective reduction. The test result of XRD showed the forming of magnetite, which were found in the pellets with mass size 5 grams. After all, fayalite phase was found in each size of pellet samples. The largest iron and nickel content was shown in the 5 gram pellets, 25% and 0.85%, respectively.