Stabilization of Ash and Slag from Combustion of Medical Waste in the Geopolymers Matrix

Abstract

This paper regards the possibility of using geopolymer matrix to immobilize heavy metals present in ash and slag from combustion of medical waste. In the related research one used the fly ash from coal combustion in one Polish CHP plant and the waste from two Polish incineration plants. It was studied if the above-named waste materials are useful in the process of alkali-activation. Therefore, two sets of geopolymer mixtures were prepared containing 60 and 50% of ash and slag from the combustion of medical waste. The remaining content was fly ash from coal combustion. The alkali-activation was conducted by means of 14M solution of NaOH and sodium water glass. The samples, whose dimensions were in accordance with the EN 206-1 norm, were subjected to 75°C for 24 h. According to the results, the geopolymer matrix is able to immobilize heavy metals and retain compressive strength resembling that of C8/10 type concrete.