Experimental Study on the Preparation of Improved Soil Substrate from Coal Gangue

Abstract

With the continuous development of China’s industry, the disorderly discharge and accumulation of coal gangue in mining areas have become a key ecological problem, which not only occupies a large amount of land, but also causes various pollution phenomena. Therefore, the comprehensive utilization of coal gangue has become a research hotspot in the field of environmental governance. In this paper, by mixing coal gangue and fly ash with straw in different ratios to prepare compound soil substrate and growing lettuce, the effects of different ratios of the three wastes and coal gangue particle sizes on crop growth were analyzed by measuring cotyledon area, plant height and other indexes. The experimental results showed that the best proportion of soil matrix improvement was 42.9% coal gangue, 7.1% fly ash, 10% straw and 40% soil, where the coal gangue particle size proportion was 20% fine particles, 20% medium particles and 60% coarse particles. This experiment mixed coal gangue with typical solid wastes, which will, to a certain extent, solve the problem of solid waste dumping and resource scarcity in China and provide a scientific reference for the comprehensive utilization of the three wastes and the repair of soil in mining areas.