Laboratory investigation on the bioremediation technology for soilization of iron ore tailings

The study's objective was to improve the physicochemical properties of iron ore tailings to restore iron ore tailings areas. The physicochemical properties of substrates with different ratios of organic matter and tailings were investigated, and plant growth on these substrates was observed to determine the effects of the mixing ratio on the physicochemical properties of iron ore tailings and identify the optimal mixing ratio. The addition of organic fertilizer and rice husk reduced the density of the substrate, increased the total porosity, and neutralized the alkalinity in the ore tailings. The water-holding capacity of the substrate was positively correlated with the content of rice husk. With increasing rice husk content, the water-holding capacity of the substrates greatly increased, as did the pore structure of the iron ore tailings. The shear strength of the substrates was optimal in Groups I and II, with cohesion peaking in Group II. However, the cohesion sharply decreased as the rice husk content increased, and the internal friction angle decreased. The optimal mixture was 100 g of iron ore tailings, 8 g of organic fertilizer, and 0.8 g of rice husk.