Application of PVAc Copolymerization Emulsion in Soil Improvement of Siderite Tailings

At present, although there were many ways to utilize the resources of siderite tailings, the utilization amount was relatively low and could not effectively solve the problem of siderite tailings storage. The soil utilization of siderite tailings has been an effective way to achieve large−scale utilization and improved utilization efficiency. However, the most significant problem with the soil utilization of siderite tailings was that their physical and chemical properties were extremely unsuitable for plant growth, so soil improvement was very necessary. In this paper, PVAc copolymerization emulsion was used for soil improvement and ecological restoration of siderite tailings. The effects of PVAc copolymerization emulsion on the consolidation strength, heat aging, freeze−thaw stability, water retention performance and physical and chemical properties of siderite tailings after treatment were investigated. The ecological effect of treating siderite tailings with PVAc copolymer emulsion was studied through field plant experiments. The research results show that the consolidation strength of PVAc copolymerization emulsion with a concentration of 2.0% on the siderite tailings soil sample reach 0.47 MPa, which could achieve the effect of inhibiting the dust of siderite tailings, and the copolymerization emulsion has more excellent heat aging resistance and water retention effect on the siderite tailings, which is conducive to the growth of plants and microorganisms. Compared with the siderite tailings treated without copolymerization emulsion, after treatment with PVAc copolymer emulsion, the pH of siderite tailings decreases from 8.92 to 7.37, the organic matter content increases from 1.13 to 4.52 g/kg, and the total nitrogen content rises from 8.18 to 12.41 g/kg. Additionally, the proportion of larger particle sizes in the soil samples show a significant increase, thereby reducing the salinization−alkalization degree of the siderite tailings while improving fertility and stability. Moreover, compared to existing polyacrylamide−based remediation agents, its usage cost can be reduced by more than 35%. Additionally, siderite tailings treated with a 2% PVAc copolymer emulsion achieve a plant survival rate of 70%, with plant height, stem biomass, and root−to−shoot ratio all significantly higher than those of the control group. Furthermore, the siderite tailings treated with 2% PVAc copolymerization emulsion had a better growth trend of microorganisms, which indicate that PVAc copolymerization emulsion has good ecological effect on the soil improvement of siderite tailings.