毒砂是铜精矿中存在的一种有害物质,在冶炼过程中造成严重的环境污染。然而,毒砂的选择性抑制仍然是浮选的挑战。本研究旨在分析硫代甘酸钠(STG)在Cu-As分离浮选中对毒砂的抑制机理。微浮选试验证实,STG 能够在黄铜矿浮选中选择性地抑制毒砂并降低铜精矿中的砷含量。局域电化学阻抗谱 (LEIS) 表明 STG 更倾向于吸附在毒砂上而不是黄铜矿上,这增强了电化学阻抗并降低了表面反应性。此外,表面吸附试验和接触角测量表明,STG阻碍了黄药丁酯(BX)在毒砂表面的吸附,从而进一步增强了毒砂的润湿性。傅里叶变换红外光谱(FTIR)、DFT计算和分子动力学模拟(MDS)结果表明,STG通过其-SH基团与毒砂表面的Fe和As位点发生化学键合,并与水分子形成氢键通过分子顶部的 -COO- 基团。最终,在毒砂、STG 和水分子之间产生了类似桥的结构。这种结构导致毒砂表面覆盖了一层稳定的亲水膜,因此其可浮性严重恶化。傅里叶变换红外光谱(FTIR)、DFT计算和分子动力学模拟(MDS)结果表明,STG通过其-SH基团与毒砂表面的Fe和As位点发生化学键合,并与水分子形成氢键通过分子顶部的 -COO- 基团。最终,在毒砂、STG 和水分子之间产生了类似桥的结构。这种结构导致毒砂表面覆盖了一层稳定的亲水膜,因此其可浮性严重恶化。傅里叶变换红外光谱(FTIR)、DFT计算和分子动力学模拟(MDS)结果表明,STG通过其-SH基团与毒砂表面的Fe和As位点发生化学键合,并与水分子形成氢键通过分子顶部的 -COO- 基团。最终,在毒砂、STG 和水分子之间产生了类似桥的结构。这种结构导致毒砂表面覆盖了一层稳定的亲水膜,因此其可浮性严重恶化。它通过分子顶部的-COO-基团与水分子形成氢键。最终,在毒砂、STG 和水分子之间产生了类似桥的结构。这种结构导致毒砂表面覆盖了一层稳定的亲水膜,因此其可浮性严重恶化。它通过分子顶部的-COO-基团与水分子形成氢键。最终,在毒砂、STG 和水分子之间产生了类似桥的结构。这种结构导致毒砂表面覆盖了一层稳定的亲水膜,因此其可浮性严重恶化。
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Insight into selective depression of sodium thioglycallate on arsenopyrite flotation: Adsorption mechanism and constructure
Arsenopyrite is a hazardous substance exist in copper concentrate, thus causing serious environmental pollution during the smelting process. However, the selective depression of arsenopyrite remains a challenge to flotation. This study aims to analyze the depression mechanism of sodium thioglycallate (STG) towards arsenopyrite in the Cu-As separation flotation. Micro-flotation tests confirmed that STG was able to selectively depress arsenopyrite in chalcopyrite flotation and lowered As content in copper concentrate. Local electrochemical impedance spectroscopy (LEIS) demonstrated that STG preferred to adsorb on arsenopyrite than on chalcopyrite, which enhanced electrochemical impedance and reduced surface reactivity. Furthermore, surface adsorption test and contact angle measurement illustrated that STG hindered butyl xanthate (BX) adsorption on arsenopyrite surface, thus the wettability of arsenopyrite was further enhanced. The results of fourier transform infrared spectroscopy (FTIR), DFT caculation and Molecular dynamics simulations (MDS) revealed that STG chemically bond with Fe and As sites on the surface of arsenopyrite through its -SH group, and it formed a hydrogen bond with water molecules via its -COO- group at the top of molecule. Ultimately, a bridge-similar constructure was generated among arsenopyrite, STG and water molecules. This constructure resulted in a stable hydrophilic film covered on arsenopyrite surface, thus its flotability was severely deteriorated.