N_5O_3-TRPO混合萃取剂从碱性氰化液中萃金

研究 N5O3- TRPO混合萃取剂从碱性氰化液中萃取金 ,考察了平衡时间、水相初始 PH值、水相离子强度、金浓度、N5 0 3浓度、磷类添加剂的种类及其浓度、稀释剂、温度、相比等因素对金萃取率的影响 ,绘制了萃取等温线 ,测定了金的饱和容量 ,考察了所选定的萃取体系对银 ( )、铁 ( )、铜 ( )、镍 ( )、锌 ( )的萃取性能 ,计算出了金与这些杂质元素的分离系数。研究了负载有机相中金的反萃。结果表明 N5O3- TRPO ROH正十二烷体系对 Au( CN) 2 具有较高的萃取率和选择性 ,可应用于碱性氰化液中金的萃取分离。     

溴代十六烷吡啶从碱性氰化液中固相萃取金的研究

基于溴代十六烷吡啶(CPB)与Au(CN)2-络阴离子生成的离子缔合物可被反相键合硅胶固相萃取柱萃取、富集,建立了一种从碱性氰化液中高富集倍数固相萃取金的方法。在碱性介质中,溴代十六烷吡啶(CPB)与Au(CN)2-络阴离子生成离子缔合物,该离子缔合物可被反相键合硅胶固相萃取柱萃取、富集,富集的离子缔合物可用乙醇洗脱,洗脱液经处理后用分光光度法测定,反相键合硅胶固相萃取柱不被破坏而且可重复使用。方法用于从碱性氰化液中固相萃取痕量金,萃取回收率可超过98%,研究了反向固相萃取金的机理,同时提出了一种从碱性氰化液中提取金的新工艺。     

N1923从碱性氰化液中萃取金(Ⅰ)的研究

采用放射性同位素198Au示踪法研究了伯胺N1923和TBP从碱性氰化液中萃取金(Ⅰ),考察了酸化率、水相pH值、萃取剂浓度等对萃取率的影响,以及NaOH对载金有机相的反萃作用。结果表明,TBP含量大于20％,酸化的N1923与KAu(CN)2摩尔比值在11时,金能够完全被萃取。载金有机相可采用0.1mol·L-1的NaOH溶液定量反萃。机理研究表明,伯胺和TBP萃取Au(CN)2-,符合BC类协同萃取机理。当金浓度大于10g·L-1时,在萃取有机相中形成纳米级的聚集体。     

多烷基支链仲胺从碱性氰化液中萃取金

研究了多烷基支链促胺从碱性氰化液中萃取金,考察了平衡时间、水相初始pH值、金浓度、离子强度、温度、萃取剂浓度、稀释剂、相比等因素对金萃取率的影响,绘制了萃取等温线,测定了金的饱和容量,考察了萃取体系对银（Ⅰ）、铁（Ⅱ）、铜（Ⅰ）、镍（Ⅱ）、锌（Ⅱ）的萃取性能,计算出了金与这些杂质元素的分离系数,研究了负载有机相中金的反萃,结果表明,该萃取体系在pH5－11范围内对Au（CN）2^－有较高的萃取率和选择性,pH1／2＝11.7,可用于碱性氰化液中金的萃取分离。     

十二烷基二甲基苄基氯化铵从碱性氰化液中固相萃取金的研究

建立了一种用十二烷基二甲基苄基氯化铵(BDMDAC)从碱性氰化液中固相萃取金的新方法:在碱性介质中,十二烷基二甲基苄基氯化铵溶液(BDMDAC)与Au(CN)2-络阴离子生成离子缔合物,该离子缔合物可被反相键合硅胶固相萃取柱萃取、富集,用乙醇洗脱,反相键合硅胶固相萃取柱可重复使用。该方法用于从碱性氰化液中固相萃取痕量金,萃取回收率可超过98%。     

N1923从碱性氰化液中萃取金(Ⅰ)的研究

采用放射性同位素１９８Ａｕ示踪法研究了伯胺Ｎ１９２３和ＴＢＰ从碱性氰化液中萃取金（Ⅰ）,考察了酸化率、水相ｐＨ值、萃取剂浓度等对萃取率的影响,以及ＮａＯＨ对载金有机相的反萃作用。结果表明,ＴＢＰ含量大于２０％,酸化的Ｎ１９２３与ＫＡｕ（ＣＮ）２摩尔比值在１：１时,金能够完全被萃取。载金有机相可采用０．ｌｍｏｌ·Ｌ－１的Ｎａ０Ｈ溶液定量反萃。机理研究表明,伯胺和ＴＢＰ萃取Ａｕ（ＣＮ）２－,符合ＢＣ类协同萃取机理。当金浓度大于１０ｇ·Ｌ－１时,在萃取有机相中形成纳米级的聚集体。     

从碱性氰化液中萃取低浓度Au(Ⅰ)的放大实验

从碱性氰化液中溶剂萃取分离Au(Ⅰ)是冶金领域研究的热点，一般金浓度为g／L级和毫升规模实验研究，而矿山的氰化槽浸液或堆浸液中金浓度，一般为1～50ppm，本文利用专门设计的搅拌萃取柱，研究了CTAB／TBP(十六烷基三甲基溴化铵／磷酸三丁酯)体系对20L规模低浓度金的萃取，以及载金有机相的反萃取行为。     

十二烷基二甲基苄基氯化铵从碱性氰化液中固相萃取金的研究

建立了一种用十二烷基二甲基苄基氯化铵(BDMDAC)从碱性氰化液中固相萃取金的新方法：在碱性介质中,十二烷基二甲基苄基氯化铵溶液(BDMDAC)与Au(CN)2-络阴离子生成离子缔合物,该离子缔合物可被反相键合硅胶固相萃取柱萃取、富集,用乙醇洗脱,反相键合硅胶固相萃取柱可重复使用。该方法用于从碱性氰化液中固相萃取痕量金,萃取回收率可超过98%。     

Lix7825从碱性氰化液中萃取分离金

研究了胍类萃取剂Lix782 5对碱性氰化液中金的萃取 ,考察了平衡时间、水相pH值、金初始浓度、离子强度、有机相中Lix782 5浓度、稀释剂的种类、添加剂浓度、温度、相比等因素对金萃取率的影响 ,测定了金的饱和容量 ,研究了Lix782 5对银、铁、铜、镍氰配合物的萃取 ,计算出了金与这些杂质元素之间的分离系数。结果表明 :萃取体系 1 % (v v)Lix782 5— 5% (v v)ROH—C1 2H2 6从碱性氰化物中萃取金具有萃取动力学速度快 ( <5min)、分相快、界面清晰、易反萃、选择性高等优点。金萃取容量可达 3 1 4g L ,并且用合成料液及实际料液进行了金的萃取分离试验 ,得到了较好的结果     

用198Au示踪法从氰化液中萃取微量金

198Au同位素示踪法;胺类萃取剂;溶剂萃取;用198Au示踪法从氰化液中萃取微量金     

The extraction of low-concentrations of gold(I) with 198Au as a radiotracer

The solvent extraction of gold from alkaline cyanide solution was studied by using ¹⁹⁸Au as a radiotracer. The influence of several variables on the gold extraction, including the concentration of gold, the molar ratio of extractants to gold(I), the volume percentage of cosolvent and the pH value of the aqueous phase, was investigated. The results indicated that the radioactive tracer technique is a quick, accurate, and convenient tool to investigate the extraction behavior of an element existing in low concentrations. The experimental results indicated that the studied amines, tetradecyldimethylbenzylammonium chloride, N1923 and tri-n-octylamine, could be used as extractants for the recovery of gold from aqueous alkaline cyanide solutions.     

Physicochemical basis of the ion-exchange separation of gold cyanide complexes

The mechanism of the separation of gold cyanide complexes is discussed, along with ion exchanger selection, selectivity, elution, and industrial applications. The ion-exchange mechanism for the sorption of gold cyanide complexes is established, and a criterion is suggested for selecting the anion exchanger for their extraction (specifically, the pK _a of the anion exchanger). The selectivity of the sorption of gold cyanide complexes by anion exchangers with rarely distributed ionogenic groups is demonstrated. A procedure for the elution of gold cyanide complexes using alkaline solutions is developed.     

Extraction of gold(III) from hydrochloric acid solutions with high-molecular aliphatic alcohols

Experiments on extraction of gold(III) from hydrochloric acid solutions with isomeric aliphatic alcohols containing 6–12 carbon atoms showed that secondary alcohols recover AuCl_4? from acid solutions with higher distribution ratios than primary alcohols do. The best alcohol that can be recommended for the extraction of gold(III) from 3–6 M HCl solutions, taking into account the solubility and extraction ability of alcohols, is 2-octanol. The possibility of efficient stripping of gold(III) from the 2-octanol phase with ammonia or thiourea solutions was demonstrated.     

Microbalance study of gold dissolution in alkaline sulfite-thiocarbamide electrolytes

It is shown that gold does not virtually dissolve in alkaline (pH 12.5) solutions containing either thiocarbamide or sodium sulfite. Gold dissolves in alkaline solutions simultaneously containing thiocarbamide (0.1 M) and sodium sulfite (0.5 M). The gold dissolution rate increases with the increase in the contents of thiocarbamide and sodium sulfite. The methods of microbalance and voltammetry are used in studying the mechanism of gold dissolution in a solution containing 0.5 M sodium sulfite, 0.1 M thiocarbamide, and 0.03 M KOH. The found relationships are explained based on the assumption that the gold dissolution in alkaline sulfite-thiocarbamide electrolytes affords gold sulfite complexes.     

Extraction of gold, palladium and platinum from chloride, bromide and iodide solution with di-n-octyl sulphide (DOS) in cyclohexane

The extraction of gold, palladium and platinum from hydrochloric acid, hydrobromic acid and iodide media by solutions of di-n-octyl sulphide in cyclohexane was examined. From distribution data it was concluded that the monosolvates AuX(3).DOS and disolvates PdX(2).2DOS are extracted. Extraction of platinum was efficient only from iodide solutions; a disolvate PtI(4).2DOS was formed. The possibility of separation of gold and palladium from platinum by extraction from bromide or chloride solutions and simultaneous extraction of palladium and platinum from an iodide medium was demonstrated.     

Extraction of gold(III) with (RS)-1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazol-1-yl-methyl)-pentan-3-ol from hydrochloric acid solutions

Extraction of gold(III) with (RS)-1-(4-chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4-triazol-1-ylmethyl)-pentan-3-ol from 3 M hydrochloric acid solutions (with chloroform as a diluent) has been studied. Optimal extraction conditions have been found. The reagent has been shown to extract efficiently metal ion from solutions containing 3 M hydrochloric acid due to formation of coordination bond between gold(III) and the N4 atom of the triazole ring. The coordination mechanism of gold(III) extraction has been proposed on the basis of the data obtained. Concentration constants of extraction have been calculated, and the thermodynamic parameters of extraction have been determined.     

Electrogenerated chemiluminescence of luminol on a gold-nanorod-modified gold electrode

Electrogenerated chemiluminescence (ECL) of luminol on a gold-nanorod-modified gold electrode was studied, and five ECL peaks were obtained under conventional cyclic voltammetry in both neutral and alkaline solutions. Among them, four ECL peaks (ECL-1-4) were also observed on a gold-nanosphere-modified gold electrode, but the intensities of these ECL peaks were enhanced about 2-10-fold on a gold-nanorod-modified gold electrode in neutral solution. One new strong ECL peak (ECL-5) was obtained at -0.28 V (vs SCE) on a gold-nanorod-modified gold electrode in both neutral and alkaline solutions and enhanced with an increase in pH. In strong alkaline solutions, ECL-1 and ECL-2 on a gold-nanosphere-modified electrode were much stronger than those on a gold-nanorod-modified gold electrode, while ECL-3-5 appeared to only happen on a gold-nanorod-modified gold electrode. The emitter of all the ECL peaks was identified as 3-aminophthalate. The ECL peaks were found to depend on the scan direction, the electrolytes, the pH, and the presence of O(2) and N(2). The reaction pathways for ECL-4 have been further elucidated, and the mechanism of the new ECL peak (ECL-5) has been proposed. The results indicate that a gold-nanorod-modified gold electrode has a catalytic effect on luminol ECL different from that of a gold-nanosphere-modified gold electrode, revealing that the shape of the metal nanoparticles has an important effect on the luminol ECL behavior. The strong ECL of luminol in neutral solution obtained on a gold-nanorod-modified electrode may be used for the sensitive detection of biologically important compounds in physiological conditions.