Release Mechanism and Stabilization Effect of Sb and As: A Case Study of the Antimony Mine in Karst Area, Southwestern China

To investigate the heavy metal enrichment mechanisms and release characteristics of typical deposits in karst areas, the Sb tailing pond of Dachang, Qinglong, Guizhou Province, China, one of the three largest Sb mines in the word, was selected as the study area.In this study, samples were collected from tailings (0~120 cm) and analyzed for changes in Sb and As content at different pH values by simulated acid rain static release experiments, and solid waste materials (fly ash, quicklime, and zeolite powder) were selected to design an orthogonal test to explore the optimal stabilization effect of Sb and As.The results showed that the average contents of Sb and As exceeded background values of Guizhou soil to different degrees.The content of As leaching revealed slight differences in the leachate.Sb was sensitive to more acidic conditions, and its release content can pose an ecological risk.Further, the best stabilization effect of Sb and As was observed after adding different ratios of fly ash, quicklime, and zeolite powder for a period of maintenance, which can be used as promising stabilizing materials for mine tailings remediation.This study provides comprehensive theoretical support for enhancing source control and risk management of heavy metals.