Effect of Sodium Carbonate on the Reduction Process of Nickel Slag from Sulawesi

Nickel slag is one of the results of the nickel ore smelting process which is still a waste and has not been used optimally. Considering the amount of nickel slag waste in Indonesia, the effort to utilize it into a more valuable product becomes very important. Therefore, in order to extract the precious metal content in nickel slag, this study aims to analyze the effect of adding sodium carbonate in the reduction process of nickel slag. In this study, the reduction process is carried out using coal as a reducing agent, where the variation of the reduction temperature is 800, 900, and 1000°C; while the variation of the ratio between nickel slag and additives is 1:1, 1:2, and 2:1. The XRD analysis results show that the temperature rise up to 1000 °C and the addition of sodium carbonate will increase the amount of sodium magnesiosilicate up to 29.4% and also hematite up to 25.1%. The same thing happened in samples with a ratio of 1:1 and 1:2 where the amount of sodium magnesiosilicate increased from 29.4% to 30.0% and hematite from 25.1% to 28.8%.