金(Ⅰ)硫脲络盐的红外吸收光谱

山口、和 Dash 等人曾对金属硫脲络盐的红外光谱作过研究。至今,有关金(I)硫脲络盐的红外光谱资料,报道甚少。本文的目的是阐明金(I)硫脲络盐中金原子与硫脲的硫,还是氮进行成键。实验部份我们根据文献合成了下列三种金(I)硫脲络盐:〔Au(Thio)_2〕_2SO_4、Au(Thio)_2NO_3和 Au(Thio)_2ClO_3。另外,我们采用离子互换反应合成了二种含金络盐,分别为 Au(Thio)_2 SCN 和苦味酸二硫脲合金(I)〔Au(Thio)_2OC_6H_2(NO_2)_3〕。合成的方法与前人稍有不     

用硫氰酸钾从季铵盐载金有机相中反萃金的研究

研究了应用硫氰权钾从CTAB-30%TBP（或30%正辛醇）-磺化煤油萃Au(Ⅰ）体系载金有机相的反萃取，以及反萃后的有机相的重复利用等，研究结果表明，应用3mol/LKSCN能够将载金有机相中（浓度为3g/LAu)90%左右的Au反萃入水相，3级反萃率接近100%，有机相经过5次循环利用后，对1g/LAu溶液的萃取率基本无变化，反萃入水相中的Au可能用NaBH4还原回收。     

白云母对氰化浸金的吸附效应研究

采用多种手段研究了金矿石中白云母对氰化浸出液中的金吸附效应。吸附试验考察了不同粒级白云母对溶液中金吸附率的影响,结果表明,白云母粒度越细,溶液中金的吸附率越高,吸附率由1.29%提高至5.35%;电化学溶解实验表明,白云母粒度越小,金的溶解速率越大;对浸金产物的扫描电镜(SEM)和能谱(EDS)分析表明,金的氰化络合物易吸附在白云母端点处;红外光谱分析显示,金氰化物与白云母存在化学吸附。密度泛函理论(DFT)模拟计算结果显示,金氰化物与白云母(001)表面的吸附强度为[Au(CN)2]^-?AuCN。     

日本一公司开始提供无电解置换型金电镀液

正田中控股株式会社发布,田中贵金属集团从事电镀业务的日本电镀工程株式会社(EEJA)开始提供不含氰化物的无电解置换型金电镀液"LECTROLESSIGS2020"。"LECTROLESSIGS2020"是一种用于对镍、钯等部件进行金电镀加工的完全无氰化的无电解置换型金电镀液。EEJA通过重新评估电镀液的成分,成功开发出一种与采用了氰化金钾(以下简称PGC)的氰系置换型金电镀液特性相同的电镀液,这种电镀液与以往的无氰置换型电镀液相比,析出(成膜)时间     

柠檬酸金钾电铸微小金结构试验研究

柠檬酸金钾含氰量低,以它为主盐的金溶液稳定性好且具有可添加性。为解决传统有氰电铸金溶液氰化物含量高、溶液危害大、处理困难及无氰电铸金溶液稳定性较差且不具备可添加性等问题,选用以柠檬酸金钾为主盐的金溶液进行电铸试验。通过对比不同加工参数,研究电流密度、阴阳极间距和冲液速度等对电铸层的影响,得到优化后的加工参数,最终在钛基片上电铸出微小金结构。     

三苯基磷氯金的电化学合成

以高纯金为牺牲阳极,在三苯基磷与浓盐酸的乙腈溶液中,用电化学方法合成了三苯基磷氯金(Au(PPh3) Cl),并经适当的纯化处理获得了Au(PPh3) Cl白色针状晶体.元素分析、红外光谱和X射线衍射分析结果表明,所制备的产物为Au(PPh3) Cl纯相,同时还对Au(PPh3) Cl电化学合成机理及相关实验条件的影响进行了讨论.     

一种无氰化学镀金工艺的研究

为了确定一种无氰亚硫酸金钠化学镀金的最佳工艺条件,并使其具有工业上的可行性,利用镀层厚度测试和镀层结合力测试等性能检测手段,研究了该工艺中镀液组分和操作条件对镀层的影响.结果表明:当溶液中亚硫酸金钠(以金计)为 1～3g/L,亚硫酸钠为13g/L,按乙二胺/Au=(6～10)∶〖KG-*2/3〗1比例投入,磷酸氢二钾为30g/L,pH为8～9,温度为50～60℃时,可以得到光亮均匀的镀金层.     

富金的Au-Ag-Zr三元合金研究

在Au-Ag、Au-Zr和Ag-Zr二元系相图研究的基础上,采用X射线衍射分析、电子探针(EPMA)和显微金相方法测定了Au-Ag-Zr三元系富金区域的700℃等温截面.发现在该等温截面上的富Au-Ag侧,沿着Au-Ag二元匀晶系存在一个长条形的单相区Au(Ag)或Ag(Au),确定在该部分等温截面上共有4个单相区:固溶体Au(Ag)或Ag(Au)、Au4Zr、Au3Zr和Au2Zr;4个二相区:Au4Zr Au(Ag)、Au3Zr Au(Ag)、Au4Zr Au3Zr和Au3Zr Au2Zr;2个三相区:Au4Zr Au3Zr Au(Ag)和Au3Zr Au2Zr Au(Ag);在该区域没有形成新的三元化合物.     

硫脲反萃金的研究

1.前言氰化法反应比较完全,回收率较高,成本较低,至今仍是金矿提金的最重要方法.但是氰化物毒性大,同时CN~-是强络合剂,可与Fe、Cu、Ni、Zn等许多贱金属络合,矿石组成复杂时试剂消耗大,金、银回收率降低.40年代国外开始研究硫脲溶金,我国70年代以来不少单位也进行了研究,兴起“硫脲热”.此法优点是浸出Au、Ag速度比氰化物快,络合选择性比CN~-高,同时毒性也比氰化物小,但由于经济原因一直未能用于工业生产.     

“ 金-硫氰酸根冶 配合物的合成及沉金性能研究

以氯化亚金和硫氰酸盐为原料,采用"选择性还原-络合"的方法首次合成了"金-硫氰酸根"配合物,并通过元素分析确定其分子式为NH4[Au(SCN)2]。按PCB行业的相关工艺要求,对该配合物的化学镀金性能进行了探讨,得到最佳沉金工艺条件为:pH值2～5,金质量浓度1～3 g/L,温度40～60℃,施镀时间9～12min。在此条件下所得的沉金层厚度可达0.12μm,满足相关行业的品质要求。     

一种新的PCB无氰化学沉金工艺

介绍了一种新的不含游离氛的无氰化学沉金工艺,并从工艺特.s、沉金效果、产品品质和环保处理等方面将该无氰沉金工艺与传统的有氛化学沉金工艺进行了对比分析,分析表明:该无氰沉金工艺的金缸溶液寿命更长,沉积均匀性更好,沉积速率可控,有利于控制金厚和降低镀金的材料成本;产品的品质有保障,过程更环保,可望替代传统的有氰工艺.     

Properties of ‘Sulpho-Chromispel-I’ electrolyte of standard concentration for the electrodeposition of chromium

The most important properties of non-standard highly efficient “Sulpho-Chromispel- I” type electrolytes for chromium plating have been investigated. They contain as side anions catalysing the cathodic process, both SO^2-₄ and I^?. The effects of cathodic current density and concentration of hydroiodic acid on the total current distribution are evaluated. The deposition rate is determined. The effect of operating parameters on the throwing power is established. The properties of the electrolytes studied are compared with those of standard sulphate electrolytes and “Chromispel-I” compositions. The most efficient electrolyte comprises CrO₃:I- = 20:1 and 20 cm³ dm^?3 sulphuric acid. The deposition rate can reach a value of 250 μm h^?1 at a current density of 200 A dm^?2. The throwing power of this electrolyte is close to that of standard sulphate electrolytes. As a whole “Sulpho-Chromispel-I” electrolytes exhibit lower throwing power compared to standard sulphate electrolytes or pure “Chromispel-I” electrolytes. They are recommended for chromium plating details of simple profile.     

高岭石对氰化浸金的影响及助浸研究

采用电化学实验研究了在氰化浸金过程中常见矿物高岭石对金溶解速率及对溶液中金的吸附效果的影响。结果表明,高岭石的存在会使金的溶解速率加快,随着高岭石粒度逐渐降低金的溶解速率提高,且高岭石对溶液中金的吸附率增加。氰化浸出实验结果表明,高岭石存在时金的浸出率由93.21%降低到91.76%,采用柠檬酸三钠、过氧化镁和十二烷基硫酸钠助浸时,金浸出率升高至94.42%。能谱分析(EDS)发现浸出物中高岭石表面有金元素存在,表明高岭石会吸附溶液中的金。红外光谱分析和密度泛函理论计算表明,高岭石与金发生化学吸附作用,氢原子为高岭石的活性位点,C6H5O7^3-会优先吸附于高岭石(001)表面,加入助浸剂可降低高岭石与金的吸附强度,提高金的浸出率。     

草酸配位浸出二段焙砂中包裹金的赤铁矿

草酸根(ox^2-)对三价铁具有强的配位能力，可用草酸配位浸出二段焙砂中包裹金的赤铁矿，提高金的回收率。考察了草酸用量、液固比、浸出温度和时间对二段焙砂中铁浸出率的影响。结果表明，用1.17倍理论量的草酸在液固比为12 mL/g时于90℃浸出2 h，铁浸出率达到75.8%以上。除铁渣进一步氰化浸出，渣中金品位为8.8 g/t，低于直接氰化浸出渣12.3 g/t的金品位。草酸浸出液主要成分为具有光催化活性的Fe(ox)⁺和Fe(ox)2^-，可采用光催化法回收铁、再生草酸，再生的草酸可返回浸铁过程。     

亚硫酸钠-柠檬酸钾体系络合剂对镀金层性能的影响

目的 研究亚硫酸钠-柠檬酸钾体系络合剂对可伐基板镀金层共晶焊接性能的影响机理,从而优化络合剂含量工艺范围,提升镀金层金锗共晶可焊性。方法 采用扫描电子显微镜及能谱仪（SEM-EDS）、X射线衍射仪（XRD）、极化曲线等分析方法,结合镀金层孔隙、金锗共晶焊接润湿性和剪切强度测试,研究了亚硫酸钠-柠檬酸钾体系络合剂,对镀金层表面金锗焊料润湿性,金锗共晶层结合力、表面和截面形貌、结晶状态、孔隙,以及金锗共晶焊接界面微观形貌等的影响。结果 亚硫酸钠和柠檬酸钾均能起到络合剂作用,当络合剂亚硫酸钠质量浓度为120～160 g/L和柠檬酸钾质量浓度为40～60 g/L时,络合剂含量的增加可使镀金液阴极过电位明显增大,从而使所制备的镀金层结晶更加致密。当络合剂亚硫酸钠质量浓度为160～200 g/L、柠檬酸钾质量浓度为60～100g/L时,电沉积的镀金层表面明显平整,截面形貌致密,孔隙少,且以（311）晶面择优生长,晶粒尺寸为43.7nm,晶面间距为0.123nm,金锗焊料润湿良好,金锗共晶层结合力较大,剪切强度可达3 MPa以上,可满足金锗共晶焊接使用要求。结论 亚硫酸钠-柠檬酸钾体系络合剂含量对镀...     

半胱氨酸亚金钠的理化性质及化镍金工艺研究

目的合成一种新型水溶性亚金配合物,并分析其应用于无氰镀金的可行性。方法以氯金酸为金液、半胱氨酸为配体,在弱碱性条件下合成半胱氨酸亚金钠,通过元素分析仪、红外光谱仪、紫外可见光谱仪、热重分析仪、电导率仪研究其理化性质。以温度、p H值和金质量浓度为变量,通过单因素试验分析它们对镀金的影响,通过正交试验获得适宜的镀金工艺条件。结果该产物的分子式为Na Au(Cys)2。该配合物的结构中,半胱氨酸里巯基和亚金进行配位并形成了很强的配位键,该配合物的特征吸收波长范围在205~210 nm。差热曲线和电导率值测定结果显示,该配合物在170℃以前的热稳定性较好,是典型的离子化合物。最佳的镀金工艺参数为:p H=2,金质量浓度2 g/L,温度45℃。在该条件下,镀层的结合力好,镀速可控,镀金效果良好。结论合成了新型水溶性亚金配合物,其理化性质稳定,有望用于无氰镀金工业领域。     

Coordination polymers with cyanoaurate building blocks: Potential new industrial applications for gold

This report illustrates the concept that aurophilic interactions of gold-containing building blocks, particularly cyanoaurates, could be used as a tool to increase structural dimensionality in systems containingother metals in addition to gold(I). Such high-dimensionality systems may have useful optical, magnetic, conducting or porous materials properties. Recent successes from our group and others in using the neglected, luminescent [Au(CN)₂]⁻ building block to synthesize supramolecular coordination polymers with interesting and potentially commercially applicable physical properties will be surveyed. In most heterometallic [Au(CN)₂]-based polymers, aurophilic interactions increase the structural dimensionality of the system and can impart increased thermal stability. The gold(I) ion can mediate significant magnetic interactions between transition-metal centres or influence iron(II) spin-transition behaviour in the polymers. The Cu[Au(CN)₂]₂(solvent)_x polymer system is dynamically vapochromic, i.e., it shows large, reversible colour changes upon exposure to solvent vapours, thereby illustrating a sensor-type application. The related d⁸, square-planer [Au(CN)₄]⁻ building block, which has only recently been incorporated into coordination polymers, does not form any aurophilic interactions; weak Au-N(cyano) interactions control the intermolecular packing. Several structural examples of cyanoaurate-based coordination polymers are presented, including 2-D and 3-D arrays. The incorporation of cyanoaurates as components of advanced materials would provide a new utility and market for these key compounds of the gold mining and refining industry.     

Application of electrodialysis technique to recover contaminated rinsing water from gold electroplating processes

Abstract

The aim of the present work was to evaluate the possibility of using an electrodialysis technique to recover rinsing water contaminated with the electrolyte during the process of gold electrodeposition. During the rinsing process the electrolyte, containing gold, silver, cyanide and contaminants, is dragged from the bath with the plated components. The more the rinsing water is used the more it becomes concentrated and therefore water replacement is necessary. In these studies three different types of electrodialysis cell containing two, three and five separate compartments were used. Two kinds of ion selective membranes, a cationic Nafion 450 and an anionic Selemion AMV, were used in the construction of the cells. The total cell potential, membrane potential and polarisation potential as a function of applied current were evaluated. The results show that it is possible to extract an average of 56% of all metal and cyanide from the rinse water working at 30 mA cm^?2 for 190 h. However, a more efficient extraction of 75% of all the metals and cyanide was obtained within 270 min of electrodialysis at a current density of 20 mA cm^?2. The results of this study showed that electrodialysis is suitable for removing contaminants from rinsing water to be returned to the process.     

Novel plating solution for electroless deposition of gold film onto glass surface

In this paper, a simple and environmentally friendly electroless plating solution of chloroauric acid (HAuCl₄) and hydrogen peroxide (H₂O₂) for depositing gold film onto (3-aminopropyl)-trimethoxysilane (APTMS) -coated glass surface has been developed. APTMS as an adhesive reagent was used to attach the gold nanoparticles (AuNPs) onto the glass substrate. These AuNPs could be regarded as the preferential nucleation or catalytic sites for gold electroless reduction, which accelerated the reduction of Au³⁺ on the glass surface and effectively prevented the formation of gold metal in the bulk solution. During the gold plating process, H₂O₂ as the reducing agent was thermodynamically capable of reducing Au³⁺ ions from the HAuCl₄ precursor to gold atoms, which deposited onto the glass surface and finally formed the continuous gold film. The resulting gold film was characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and atomic force microscope (AFM), respectively.