Effect of 10, 20, 30, 40 wt% MgO addition on Ferronickel Slag Roasting to Produce Raw Materials for Refractory

Nickel is the main alloying element of stainless steel. Along with the increasing demand for stainless steel, the demand for nickel will also increase. Currently, the Indonesian government plans to add several smelters. Along with the increase in the number of smelters, this will have an impact on the production capacity of nickel and other metals. The positive impact that can be felt is the increase in the country's foreign exchange in terms of investment and also exports and imports. However, in the nickel extraction process, there is more slag was produced than the product itself. Then the waste in the form of slag in production will also increase. So the authors research and prove that this ferronickel slag can still produce a much more useful and useful output. This study aims to make refractory material from ferronickel slag with the addition of MgO which is compacted and through a roasting process. The magnesia additive variables used were 10, 20, 30, and 40 wt%. The roasting process was carried out at a temperature of 1200, holding time for 30 minutes, and oven heat rate of 5℃/minute. The results of the roasting process carried out two characterizations and 1 test. For characterization using SEM-EDS (Scanning Electron Microscope – Energy Dispersive X-Ray) and XRD (X-Ray Powder Diffraction). The test carried out is a compressive strength test. In the production of refractory raw materials, it is found that forsterite (Mg2SiO4) and spinel phases are increasing along with the addition of MgO additives. In terms of compressive strength, there is a maximum point obtained when adding 30 wt% additives.