| Popis: |
Solid waste management in urban developed areas include collection, sorting, recycling of waste; the rest is incinerated. The incineration process, in addition to disinfection, reduces the volume of waste by 90% and 70% by weight.1 The remaining residues are further sorted to separate ferrous and non-ferrous metals. Most of the incinerators used for incinerating municipal solid and non-hazardous wastes are of grate furnace type, and the different fractions of ashes are named based on the location of collection and the size of the fraction. Bottom ashes are classified as non-hazardous, and those which conform to environmental and technical specifications are used mainly as road subbase material, and for other construction applications. The utilisation of residues helps to establish a circular economy, and saves landfill space and taxes and also reduces the need for mining of primary raw materials. These residues have the potential to be utilised in a higher value application such as a cement replacement, as a cement raw meal additive, and as aggregates. Certain properties of the material are obstacles that hinder the effective utilisation. Ongoing investigations explore different methods to beneficiate residues and make them fit to be used for potential high value applications. |
