Effects of temperature on the direct reduction of Southeast Sulawesi’s limonite ore

Abstract

Mining industry is one of the most important industries for the improvement in people’s value in daily lives. Indonesia has abundant mineral resources. Nevertheless, these minerals are still in the depths of the earth and need to be explored so that the minerals are on the surface of the earth. In addition, it is necessary to also extraction process to be more efficient in the next process. Therefore, the method of mineral extraction needs to be further developed to obtain optimal results with the best use of energy but at the most competitive cost. In this study, the objective is to know the effect of reduction temperature on the increase of nickel contents in nickel laterite process using a pyrometallurgy extraction which will be performed in the varying temperature of 700°C, 800°C, 900°C, and 1000°C. The mixture contains coal reducer which will reduce iron metal and supposedly increase the nickel contents in nickel laterite ore. Moreover, Na2SO4 will be added as a constant variable where the sulfur in Na2SO4 is known to help extracting the nickel laterite. The tests include XRD, AAS, and proximate and ultimate test from coal. The result of this study shows that 700°C is the optimum temperature in doing the nickel laterite reduction. Apart from some factors that affect the final result, it is only at the temperature of 700°C that the nickel contents facing an increase from 1.16% to 1.18% after being reduced in a muffle furnace for an hour.