A new technology for treating waste incineration fly ash by shaft furnace

Abstract

At present, lots of municipal solid wastes (MSWs) are treated by incineration technology, which produces a large amount of fly ash that needs to be treated innocuously. A new method of using metallurgical shaft furnace to treat the MSW fly ash was thus proposed, and some research was done for this method. Firstly, the basic physical properties of MSW fly ash were analyzed, and then, the briquetting experiment and melting treatment of MSW fly ash were explored. In the process of briquetting, the influence of different factors (water content, cement content, forming pressure and curing time) on the compressive strength of the briquettes was studied. The results showed that with the increase in water content, cement content, forming pressure and curing time, the compressive strength of the briquettes increased correspondingly. However, the compressive strength of the briquettes showed a downward trend when these values exceeded a specific range. In the melting experiment, it was found that some heavy metals (such as Cr, Be and Ba) could be solidified in the slag when the fly ash was treated at 1450 °C for 50 min, and the leaching toxicity of heavy metals was lower than the landfill standard of waste in China. At the same time, the decomposition rate of dioxins in fly ash reached 99.66% after melting treatment.