Coal-fired power plants are main contributors to atmospheric CO 2 emissions. They also produce huge amounts of coal fly ash (CFA) waste, which is typically landfilled, posing significant environmental risks due to its high content of potentially toxic elements (PTE). However, CFA is an alkaline aluminosilicate-rich waste, which offers the possibility of CO 2 mineral capture and the production of economically-relevant mineral by-products such as zeolites. Yet, the combined carbonation and zeolite production from CFA resulting in PTE trapping has never been explored. Here we show that under mild hydrothermal conditions (150 °C) and depending of process parameters such as pH and background alkali metal ion in alkaline (bi)carbonate solutions, a carbonation efficiency of up to 79%, with a net CO 2 mineral capture of 0.045 g/kg CFA can be achieved, even when using a low Ca and Mg (3.72 wt% CaO, 1.74 wt% MgO) Class F fly ash. Moreover, amorphous zeolitic precursors and different crystalline zeolites (yield 1 up to 60 wt%) are simultaneously obtained, and PTE in CFA are effectively trapped into the newly formed calcite, zeolitic precursors, and zeolite phases. These results have important implications for carbon capture and storage, as well as for the safe reutilization and disposal of CFA waste.