The Effect of Roasting Prior to The Leaching Process of Alkalinized Ferronickel Slag Followed by Precipitation Process

As a by-product of ferronickel production, ferronickel slag was created. Because of its composition, it has the potential to be used as a raw material for some valuable elements through a series of processing. The purpose of this research is to determine the effect of roasting ferronickel slag and Na2CO3 prior to hot water leaching and precipitation to obtain silica precipitate. To produce sodium silicate, ferronickel slag was roasted with Na2CO3addition. It was then dissolved by leaching for 120 minutes in hot water at around 90 °C. Silica precipitate is made by precipitating dissolved sodium silicate and aging it for three days. According to the findings, roasting causes a change in composition, which influences the leaching percentage and silica recovery. Size reduction of leaching residue from its RAF (roasted alkalinized ferronickel slag) demonstrated that reactions occurred from the surface to the core. When water is leached, sodium silicate in the form of Na4SiO4 is observed and dissolved. The precipitation and aging of sodium silicate solution produced silica precipitate with particle sizes greater than 100 μm. The highest silica recovery is obtained by roasting at 1000 °C for 240 minutes.