季铵盐类离子液体萃取Au(S2O3)23-性能研究

硫代硫酸盐提金是一种绿色环保的非氰提金方法,但高效回收金浸出液中的金尚待进一步研究。以甲基三辛基氯化铵(TOMAC)为萃取剂,考察了萃取条件（萃取剂浓度、相比、萃取时间）及金浸出液性质（pH、硫代硫酸盐浓度、初始Au(I)浓度）对TOMAC萃取Au(Ⅰ)性能的影响。结果表明：室温条件下,TOMAC为萃取剂能从硫代硫酸盐金浸出液中高效萃取Au(Ⅰ)。当A/O=1、pH=9、硫代硫酸盐浓度0.1 mol/L、TOMAC浓度1.8 g/L时,对低浓度金(0~25 mg/L)几乎能完全萃取;采用1 mol/L NaCl能有效反萃出TOMAC有机相中的Au(Ⅰ)。TOMAC萃取Au(Ⅰ)的机制为：TOMAC通过其表面的Cl-与溶液中的Au(Ⅰ)发生离子交换,形成[C25H54N]3[Au(S2O3)2]络合物。TOMAC对Au(S2O3)23-具有良好的萃取性能,可实现硫代硫酸盐金浸出液中Au(I)的高效回收,具有对硫代硫酸提金技术的潜在应用价值。     

超声波对硫代硫酸盐浸金体系稳定性的影响

探索了超声波作用对铜氨硫代硫酸钠浸金体系稳定性的影响。考察了不同浸出时间、温度、超声波功率、pH和氨水浓度条件下,浸金体系内硫代硫酸根离子浓度以及Cu(NH_3)_4~(2+)络合离子浓度变化规律。结果表明,超声波作用使硫代硫酸盐浸金体系稳定性有所降低,一定条件下可显著促进硫代硫酸根离子和Cu(NH_3)_4~(2+)络合离子浓度的降低。金矿石浸出试验表明,当Na_2S_2O_3浓度为0.1mol/L、CuSO_4浓度为0.03mol/L、NH_3·H_2O浓度为0.45mol/L时,超声波作用能够显著提高浸金率,在较低浸出温度下引入超声波辅助浸出就能达到常规较高温度下的浸出效果。本研究为降低硫代硫酸盐浸金反应的温度开辟了新的路径。     

氰化法、硫代硫酸盐法、硫脲法浸出某难浸银精矿比较研究

对某浮选银精矿采用氰化法、硫代硫酸盐法、硫脲法进行银浸出实验,以评估3种不同浸出方法对该银精矿浸出效果．研究结果表明：在最优的工艺参数下[氰化法：碱预处理后加入铵盐,氰化钠浓度0.15 mol/L,pH值为11,液固比（浸出液体积与试样质量之比,单位是mL/g,下同）2∶1,搅拌强度500 r/min,浸出时间为48 h;硫代硫酸盐法：氧化焙烧预处理,氨水浓度1.0 mol/L,硫酸铜浓度0.01 mol/L,硫代硫酸钠浓度0.2 mol/L,pH值为10,液固比4∶1,搅拌强度500 r/min,浸出时间12 h;硫脲法：氧化焙烧和稀硫酸预浸处理,Fe3+浓度7.5×10-3 mol/L,硫脲浓度0.18 mol/L,pH=1.0,液固比为3∶1,搅拌速度250 r/min,浸出时间24 h],硫代硫酸盐方法获得的Ag浸出率为78.58%,硫脲相应获得的Ag浸出率为62.43%,比氰化法获得的浸出率低约3.33%．     

长江中下游地区金矿床金的迁移形式新探

探讨了长江中下游地区金矿床的形成机制，认为原生金矿床中液态纳米金矿物是金的主要迁移形式；在表生条件下，金的硫化硫酸盐配合物及胶态金矿物是金迁移的主要形式。     

均匀沉淀法制备ZnS超细粉的新方法

制备ZnS超细粉通常是采用硫代乙酰胺(TAA)作为硫源，用化学合成法制取，但使用该原料在合成过程中易出现团聚现象，且价格昂贵；提出了采用一种低成本，且相对易于控制的原料硫代硫酸钠作为硫源，用均匀沉淀法制备ZnS超细粉的方法，并讨论了PH值温度对反应的影响。实验结果表明，用该方法可制得均匀、球形的ZnS超细粉末，且均匀粒径约为20nm。     

A novel fiber‐coated strong base‐type anion exchanger with superfast kinetics. Removal and recovery of silver thiosulfate from aqueous solutions

A commercial acrylic fiber with 92% (w/w) acrylonitrile content was partially hydrolyzed converting a fraction of the nitrile (? CN) groups to carboxylic acid (? COOH) groups, to coat the fiber with polyethylenimine (PEI) resin, which was then crosslinked with glutaraldehyde and further quaternized with ethyl chloroacetate to produce a novel strong‐base anionic exchanger in the form of fiber. Designated as PAN(QPEI.XG)(Cl^?), the fibrous sorbent was compared with a commercial bead‐form resin Amberlite IRA‐458(Cl^?) in respect of sorption capacity, selectivity, and kinetics for removal of silver thiosulfate complexes from aqueous solutions. Though the saturation level of [Ag(S₂O₃)₂]^3? on PAN(QPEI.XG)(Cl^?) is considerably less than that on IRA‐458(Cl^?), the gel‐coated fibrous sorbent exhibits, as compared to the bead‐form sorbent, a significantly higher sorption selectivity for the silver thiosulfate complex in the presence of excess of other anions such as S₂O₃^2?, SO₄^2?, and Cl^?, and a remarkably faster rate of both sorption and stripping. The initial uptake of the sorbate by the fibrous sorbent is nearly instantaneous, reaching up to ～80% of the saturation capacity within 10 s, as compared to only ～12% on the bead‐form sorbent. The high initial rate of uptake fits a shell‐core kinetic model for sorption on fiber of cylindrical geometry. With 4M HCl, the stripping of the sorbed silver complex from the fibrous sorbent is clean and nearly instantaneous, while, in contrast, a much slower rate of stripping on the bead‐form sorbent leads to its fouling due to a slow decomposition of the silver thiosulfate complex in the acidic medium. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2604–2613, 2006     

降低有机胺脱硫剂中硫代硫酸根含量的方法

采用G树脂除硫代硫酸根的方法,将有机胺脱硫剂中硫代硫酸根的浓度控制在工艺要求范围内。介绍了有机胺脱硫剂中硫代硫酸根含量高的危害以及降低其含量的过程和实际运行情况。     

测定CI-时大量S2O3^2-干扰的消除方法

研究大量硫代硫酸根离子对摩尔法测定Cl-千扰的消除方法,建立向样品中加硝酸使硫代硫酸根离子转变成单质硫沉淀和二氧化硫气体,消除氯离子测定过程中硫代硫酸根离子干扰的方法,确定最佳操作条件．该方法精密度及准确度均较好,并已应用于硫化黑工艺废液提取硫代硫酸钠过程中Cl-的检测．     

A new extraction process of carbonaceous refractory gold concentrate

A new hydrometallurgical process for a carbonaceous refractory gold concentrate at ambient temperature and pressure was presented, including grinding-leaching, intensified alkaline leaching（IAL）, thiosulfate leaching and cementation by zinc powder. The experimental results show that the grinding-leaching and intensified alkaline leaching process result in the selective oxidation of arsenopyrite and pyrite. The oxidation ratio of As is 96.6%, and 46.7 % for S. The total consumption of NaOH in alkaline leaching is only 28 % of that theoretically calculated under the conditions of full oxidization for the same amount of arsenopyrite and pyrite transforming into arsenates and sulfates, and 83.6% of gold is synchro-dissoluted by thiosulfate self-generated during pretreatment. Since the carbonaceous matter in concentrate possesses a strong capability of preg robbing, the cyanidation process is not suitable for the extraction of gold after pretreatment. However, the gold leaching rate by thiosulfate leaching for 24 h is increased to 91.7% from 0 - 3.2% by ultra-fine grinding without the pretreatment. The recovery of gold by zinc cementation gets to 99.6%. Due to the thiosulfate self-generated during alkaline leaching, the reagent addition in thiosulfate leaching afterwards is lower than the normal one.     

A Review of Ammoniacal Thiosulfate Leaching of Gold: An Update Useful for Further Research in Non-cyanide Gold Lixiviants

This literature review provides an update of ammoniacal thiosulfate as a potential lixiviant of gold, the history of thiosulfate leaching and recent progress on thiosulfate leaching of gold, as well as the production, oxidation, and stabilization of thiosulfate. The leaching results of different types of gold ores including oxide, sulfide, carbonaceous, and refractory ores/concentrates and the fundamentals relevant to the oxidation of pure gold are summarized. The factors affecting gold leaching such as pH, temperature, and oxidants in leaching solutions, reagent concentrations, and foreign ions are presented to update the current understanding on gold dissolution in a Cu(II)-NH₃-S₂O₃^2-system.