Hydrophobic modification of sulfur-containing waste rock is a promising strategy for reducing acid mine drainage (AMD) generation. This study investigated the use of sodium oleate and nano silca to modify sulfur-containing waste rock and evaluated the acid-suppressive properties of the sodium oleate and nano silca treatment through static and dynamic leaching tests. Results from these tests indicated that the pH of the leachate from the modified waste rock remained stable above 6.0. The results of 30-day dynamic tests also showed that the inhibition rate of acid generation could be more than 65 % and the reduction rate of total Fe can be more than 85 %. Furthermore, a protective film was formed on the surface of the modified waste rock, and the contact angle was increased to 84.3° compared with the original waste rock (17.9°). Sodium oleate interacted with Fe2+ and Fe3+ to form iron oleate complexes, which were encapsulated on the surface of the waste rock, thus effectively preventing the oxidation of the waste rock and thus inhibiting the generation of acidic water. X-ray photoelectron spectroscopy (XPS) results showed that the C 1 s signal of the modified waste rock sample was enhanced and the characteristic COO-Fe peaks appeared. Additionally, the ratio of the C–C/C–H to O-C = O characteristic peaks increased with the presence of nano silca powder. These findings indicated that ferric oleate complexes facilitated the attachment of nano silca to the surface via van der Waals forces, which filled the pores of the hydrophobic film layer.This study provides a viable solution to the ability of sulphur-containing waste rock to resist oxidation and inhibit acid production.

中文翻译：

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含硫废石表面疏水改性源头控制酸性矿山排水


含硫废石的疏水改性是减少酸性矿山排水 （AMD） 产生的一种很有前途的策略。本研究调查了油酸钠和纳米硅石改性含硫废石的用途，并通过静态和动态浸出测试评价了油酸钠和纳米硅石处理的抑酸性能。这些测试的结果表明，改性废石渗滤液的 pH 值在 6.0 以上保持稳定。30 天动态测试的结果还表明，对酸生成的抑制率可达 65 % 以上，总铁的还原率可达 85 % 以上。此外，改性废石表面形成保护膜，接触角与原废石 （17.9°） 相比增加到 84.3°。油酸钠与 Fe2+ 和 Fe3+ 相互作用形成油酸铁络合物，这些络合物被封装在废石表面，从而有效防止废石的氧化，从而抑制酸性水的产生。X射线光电子能谱（XPS）结果表明，改性废石样品的C 1 s信号增强，出现特征性COO-Fe峰。此外，C-C/C-H 与 O-C = O 特征峰的比率随着纳米硅粉的存在而增加。这些发现表明，油酸铁配合物通过范德华力促进了纳米硅树脂与表面的结合，范德华力填充了疏水膜层的孔隙。这项研究为含硫废石抵抗氧化和抑制酸产生的能力提供了一种可行的解决方案。