The municipal solid waste incineration (MSWI) bottom ash is the main by-product in the waste-to-energy plant, which accounts for about 80% of the total by-products. The further challenge after incineration is to find a suitable way to dispose or use the solid residue. It is well understood that the bottom ash contains contaminants, such as heavy metals, which pose an environmental risk. In order to reduce landfill of these residues and enhance the recycling of resources, different treatments are applied to upgrade the quality of the bottom ash, for instance, weathering, washing, etc. However, the treatments on the MSWI fine bottom ash particles are less sufficient. Hence, in this study the thermal treatment is applied on fine bottom ash and its effect on the bottom ash properties are investigated