Fabrication of solidified bodies by utilizing mechanochemically modified fly ash powder

Abstract

Fly ash (FA), an environmental pollutant created in combustion of coal for energy production, is generated in huge amounts worldwide every year. Among the considerable number of utilizations, FA has been used as a suitable silicon (Si) and aluminum (Al) supplier in synthesis of geopolymers. We previously reported a detailed study on surface modification of FA via mechanochemical (MC) treatment with regard to the dissolubility dynamics of Si and Al ions in alkali solutions. Here, we present the fabrication of solidified bodies using MC-modified FA with a low-concentration alkali solution at low temperature as a practical application. In addition, the chemical states of Si and Al in MC-modified FA powders and solidified bodies were systematically investigated further, showing them to be well-correlated with the dissolubility of FA powders and mechanical strength of solidified bodies.