The effect of addition of sodium sulphate (Na2SO4) to nickel slag pyrometallurgical process with temperature and additives ratio as variables

Abstract

Nickel industry is one of the most strategic industries because its widely used. Nickel slag as a by-product of nickel processing presents the potential for improving process efficiency. In this study aim to determine the effect of the addition of sodium sulfate additives and also the temperature in the reduction process of nickel slag. The research was preceded by preparation of nickel slag samples with crushing and sieving up to 200 mesh. The nickel slag is then reduced at 800°C, 900°C and 1000°C temperature without adding sodium sulfate and by adding sodium sulfate with 1 hour holding time. Furthermore, the results of the reduction is done XRD and AAS testing to see changes in the content of elements and compounds in nickel slag that has been tested. The results of the study explain that the content of the dominant impurities which is in the form of SiO2 decreases as the temperature of the reduction and iron from Fe-rich Forsterite compounds will be liberated and will bind to sulfur derived from sodium sulfate to form troilite (FeS). This results in an increasing content of valuable minerals present in the nickel slag.