Sustainable Mining and Metallurgy

The restoration of soil characteristics around mining induced ground fissures is an important content and key to realize ecological restoration and soil and water conservation in coal mining subsidence areas in the middle reaches of the Yellow River. Taking the soil in the mining induced ground fissure development area of the coal base in northern Shaanxi as the research object, through field sampling, indoor soil culture test, comparative analysis and other methods, the remediation effect of adding exogenous biochar on the physical, chemical and microbial properties of the soil in the mining induced ground fissure development area was studied and revealed. The results show that the addition of exogenous biochar could repair the physical, chemical and microbial properties of the soil around the mining ground fissures, and the improvement of soil microbial properties is the most significant, with the maximum improvement of 84% compared with that before repair. The addition of exogenous biochar has the most obvious repair effect on the physical, chemical and microbial properties of the soil at a horizontal distance of 20cm on both sides of the mining ground fissure. The addition of 3% exogenous biochar is the best addition amount to repair and improve the physical, chemical and microbial properties of the soil in the mining induced ground fissure development area.