Method for preparing rich-mineral carbon-based modifier from fly ash

The invention discloses a method for preparing a rich-mineral carbon-based modifier by utilizing fly ash, which comprises the following steps: firstly, building an electrodialysis device, carrying out electrolytic treatment on fly ash by utilizing an electrodialysis technology to remove most harmful heavy metal ions in fly ash, then uniformly mixing the fly ash with garden waste biomass powder, and carrying out thermal cracking and cooling in a nitrogen atmosphere to obtain the rich-mineral carbon-based modifier. The electrodialysis and carbonization technology is utilized, the activity of heavy metal pollutants in the fly ash can be reduced to the maximum extent, and therefore the environmental safety of fly ash application is improved, the high mineral content in the fly ash can endow the carbon-based modifier with the advantages of mineral fertilizer, the soil fertility and the crop yield are promoted, and the improvement effect is achieved. Moreover, the investment of exogenous fertilizers can be reduced,