Physicochemical Properties and Planting Performance of Artificial Soil Developed from Multiple Coal-Based Solid Waste Materials

Abstract

Using coal-based solid waste (CSWM) to develop artificial soil (AS) can solve the shortage of planting soil in mine ecological restoration and realize the resource utilization of solid waste, which is a very promising research direction. This study used three common CSWM, coal gangue (CG), fly ash (FA), and desulfurization gypsum (DG), to prepare AS. The physicochemical properties of AS, such as bulk density, specific gravity, porosity, field water capacity, available nutrient content, pH value and EC value, were studied. Simultaneously, Elymus dahuricus was utilized in pot experiments to explore the planting performance of AS. Results show that, as the CG content decreased, the specific gravity of AS decreased, and the porosity increased. Both field capacity and saturation capacity demonstrated a notable upward trend. The results of pot experiments showed that plant growth was best when the CG content in AS was 80% and the FA and DG content was 20%. In comparison to the control group consisting of pure CG, the plant biomass in the optimal experimental group exhibited a significant increase of 20.48%. This study verified the feasibility of making AS by combining various CSWM, and provides a new pathway for ecological restoration and resource utilization in mines.