从化肥厂的下脚料中提取稀贵金属

江苏省宜兴县稀有金属冶炼厂最近在华东金属回收管理处的指导和帮助下,从钙镁磷肥生产的下脚料阳极泥中提取钌、金、铂、钯等稀贵金属,并已通过鉴定。目前我国还尚未找到钌、铂等金属的富矿,大多需从国外进口。从化肥生产下脚料中回收利用稀贵金     

铅火试金富集—发射光谱法测定化探样品痕量金、铂和钯

试样用铅火试金富集铂组元素及金,加入1 mg银,在950℃熔融得到含贵金属的铅扣。铅扣与熔渣分离后在900℃灰吹得含铂、钯和金的银合金粒。把合金粒装入电极,以发射光谱法同时测定铂、钯和金的含量。     

神通广大的铂族金属

铂族元素包括铂(Pt)、钯(Pd)、钌(Ru)、铑(Rh)、锇(OS)、铱(Ir)六种金属元素。在铂族元素矿物中,这六种元素彼此之间通常构成范围广泛的类质同相现象,同时还会有铁、镍、钴某类质同相混入物。铂族金属与金、银一起同列为贵金属,但铂族金属发现远不及金、银,显得十分“年青”。在铂族金属中,用量最大、用途最广的是铂,其次是钯,两者合计占整个铂族金属产量和用量的90%以上。铂族金属神通广大,广泛应用于现代工业领域,从     

含有铜、贵金属的废料和／或矿泥的处理方法

本发明的目的是从含有铜、贵金属的废料和／或矿泥中有效地回收铜、贵金属等有用金属，其中使用化铁炉处理含有铜以及金、银、铂、钯、铑、钌贵金属中的至少一种或一种以上有用物质的铜、贵金属的废料和矿泥。所述处理含有铜、贵金属的废料和／或矿泥的方法包括：将粉碎处理成粒径≤10mm的可燃性铜、贵金属废料与粒径≤3mm的粉末状非可燃性铜、贵金属废料和熔剂一起由化铁炉的风口吹入.     

硫脲络合金银的机制及回收方法

前言随着电子工业的迅速发展,对一些贵重金属(如金、银、钯、铂等)的需求量逐渐增加.人们不得不注意从报废的产品与废液中回收贵金属,以获得材料的充分利用.研究回收金银的方法很多,作者已著文加以介绍.一般来讲,从废液中提取金银,可用氰化物、硫脲、汞、氯气、王水、硫代硫酸盐等方法.自从1887年氰化溶金专利问世以来,人们不断探索无毒提金工艺.特别是硫脲溶金银方法,日益受到普遍关注.但长期以来,研究回收机制尚未足够.本文试图剖析硫脲络合金银的机制,並介绍国内外近期的一些回收方法.     

多组分废催化剂中钯的分离工艺研究进展

简述了废催化剂中钯分离回收的基本过程和方法,指出多组分废钯催化剂具有很高的回收价值,但存在组分多、分离困难的问题。对于多组分废钯催化剂中钯与贵金属金、银、铂、铑等,以及与非贵金属铜、钴、镍、铁等的分离技术分别进行了简要介绍与评价。结果表明,化学沉淀法、溶剂萃取法、还原法、置换法是目前多组分废钯催化剂常用的回收方法。其中化学沉淀法是使用最多的方法,但存在回收周期长、复杂、成本较高的问题,而溶剂萃取法具有分离效果好、过程简单的优点,成为最具发展前景的方法。因此选择性高、无污染并适合大规模工业化的萃取新工艺成为未来的发展方向。     

贵金属系列电刷镀溶液

<正> 一、前言贵金属包括金、银、铂、铑、钌、钯、镓和铼等金属。它们都具有很高的抗化学侵蚀性和特殊的电化学性能。因而,通常采用这些金属的镀层来保护基体金属的腐蚀和变色;在电解工业中作为不溶性阳极;以及用于防止     

贵金属SiO2核壳纳米材料的研究进展

从单金属、双金属或多金属的SiO2核壳体系出发,论述了几种典型的贵金属金、银、铂、钯、铑等为核或壳与SiO2包覆的核壳纳米材料的制备方法,改进的性质和在催化、光学、生物等方面的应用,并对未来的发展方向进行了展望.     

贵金属催化剂的研究进展

贵金属因其完美的质感和独特的金属色泽,自古便被人们视为财富和高贵的象征。随着科技水平的不断进步,贵金属优良物化特性逐渐引起了人们的关注,并将其广泛地应用于工业催化领域,收到了良好的效果。综述了钯(Pd)、金(Au)、铂(Pt)系和银(Ag)这4类贵金属在催化领域的研究进展,并进行了展望。     

两种国产铂族金属化合物新产品问世

铂族金属有六种,即铂、钯、铱、铑、锇和钌。它们虽然广泛分布在地壳中,但是由于它们极为分散,所以很难提取,因此与金、银一样,往往称为贵金属。化学试剂中的锇酸是铂族金属锇的化合物,又名四氧化锇,分子式OsO_4,分子量     

铜阳极泥分铜液综合回收稀贵金属

以铜阳极泥硫酸化焙烧-酸浸脱铜所得分铜液为原料,采用Fe²⁺原位还原分铜液中的Te、Au、Pt和Pd,协同生成新生态胶体状碲选择性高效捕集Au、Pt和Pd等贵金属。根据铜阳极泥的预处理工艺,分析了贵金属在分铜液中的溶解机理;通过热力学计算绘制了As-Fe-H₂O系电位-pH图,指导调控分铜液电极电位;根据分铜液中主要金属离子的电极电位,探讨了分铜液原位还原稀贵金属机理。在Fe²⁺浓度为2g/L、搅拌速度为300r/min和85℃的优化条件下反应1.5h,贵金属Au、Ag、Pt和Pd的沉淀率分别为100%、100%、99.2%和99.6%,Se、Te和As的沉淀率分别为33.3%、36.1%和16.8%,沉淀渣中Te、Au、Ag、Pt、Pd品位分别为18.24%、124g/t、10.54%、1010g/t、320g/t,XRD分析表明,沉淀渣物相组成主要为AgCl,其他成分呈非晶态或含量较低未出现明显衍射峰,微观形态主要为细微颗粒和较规则晶体状,SEM面扫描图谱显示银和氯具有明显一致的富集区域,砷与铁具有较一致的富集区域,主要形成AgCl、FeAsO₄物相赋存渣中。该工艺简单、成本低、对环境友好,实现了分铜液中稀贵金属的高效综合回收。     

负载金属的ZIF-8催化活性的计算化学研究

金属-有机骨架材料（metal-organic frameworks,MOFs）是一类新型纳米多孔功能材料。由于其独特的结构特征,在催化方面展现出潜在的应用价值。采用分子模拟结合密度泛函理论的计算方法系统地研究了ZIF-8在负载金属Pd、Ag、Pt、Au后的催化活性。结果表明,金属与材料之间主要有3种作用方式,其中以“碳-金属-碳”（C-M-C）形式最为稳定。并且对于同一种方式,ZIF-8负载金属后的稳定性顺序为：Pd >Ag >Pt >Au。同时,利用CO作为探针分子,系统地研究了负载金属后ZIF-8的催化活性,发现这些金属原子的Lewis酸性强弱与其电子接受能力有关,其催化活性顺序为：Pd >Pt >Ag >Au。这为研究利用MOF材料负载金属用于催化提供了参考信息。     

An interpretation on the origin of the specular reflectance change caused by the submonolayer formation of foreign metals on some precious metal electrodes

The optical properties of foreign metal submonolayers formed on Au, Ag, Cu, Pt and Pd electrodes through the underpotential deposition have been investigated by specular reflectivity measurement. Based on the spectral characteristics, 14 adsorbate-substrate systems were classified into 2 groups. The first group, involving Bi on Au, Cu on Au, Pb on Au, Tl on Au, Tl on Ag and Cd on Cu, is characterized by the similarity of the optical properties of the adsorbed metal in the submonolayer to those of bulk metal. The first monolayer was found to form through several submonolayer stages, in which the optical constants are slightly different from each other. In the second group, involving Cd on Au, In on Au, Sn on Au, Ag on Pt, Bi on Pt, Cu on Pt, Pb on Pt and Bi on Pd, the spectra of submonolayer observed experimentally differ from those calculated with the assumption that the optical properties of adatom and substrate are the same as those of corresponding bulk metal. The difference in the work functions between adsorbate and substrate materials in this group is larger than those in the first group.From these findings, some considerations were made to interpret the origin of the specular reflectance change due to the presence of metal adlayer on the electrode surface. The results allow a tentative conclusion that the reflectivity change is predominantly attributed to the optical properties of the adsorbed submonolayer, but at the same time the work function of the substrate and the interband transition in visible should also be taken into consideration.     

Noble metal ion sorption by pyridyl and bipyridyl group‐containing chelating polymers

A series of eighteen 4‐vinylpyridine and 4‐methyl‐4′‐vinylbipyridine copolymers with different crosslinkers was examined as sorbents for the noble metal ions of Ag(I), Au(III), Pd(II), and Pt(II) from aqueous solutions. The chelating polymers possess appreciable sorption selectivity for Au(III) over Ag(I) and for Pd(II) over Pt(II). Binding abilities of the copolymers toward the noble metal ions vary as the identity of the chelating heterocyclic amine moiety and the structure of the crosslinkers are altered. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 207–213, 2001     

Quaternary Amine Modified Persimmon Tannin Gel: An Efficient Adsorbent for the Recovery of Precious Metals from Hydrochloric Acid Media

Persimmon tannin was chemically modified to prepare a quaternary amine type of adsorption gel, named as quaternary amine modified persimmon tannin (QAPT) gel. The QAPT gel has been used to investigate the adsorption behaviors for Au(III), Pd(II), and Pt(IV) from HCl media. It was found that the gel exhibited good selectivity towards precious metals over a wide concentration range of HCl. However, it exhibited poor affinity towards base metals such as Cu(II), Fe(III), Ni(II), and Zn(II). The adsorption isotherms of the gel for precious metal ions were described by the Langmuir model. The maximum adsorption capacities for Au(III), Pd(II), and Pt(IV) were evaluated as 4.16, 0.84, and 0.52 mmol g^?1, respectively. Although the anion exchange is the main mechanism for the adsorption of anionic species of Au(III), Pt(IV), and Pd(II), adsorption of Au(III) is followed by subsequent reduction, which results in the extraordinary high adsorption capacity for Au(III). Adsorption behavior of QATP gel for Au(III) was also compared to that of the persimmon tannin, the feed material.     

Nucleation behavior in electroless displacement deposition of metals on silicon from hydrofluoric acid solutions

We investigate the nucleation behavior in the electroless displacement deposition of metal particles (Pt, Rh, Pd, Cu, Ag, and Au) onto n-Si wafers from a metal-salt solution containing HF. The particle density of metals varies widely from 10⁶ (Pt) to 10¹¹ (Au) cm⁻², depending on the kind of metal. Deposited metals can be classified into two types of nucleation behavior. One consists of the platinum group elements, including Pt, Rh, and Pd, which display lower particle densities than elements of the other group and depend on the type of pretreatment of the n-Si wafer, and thus the surface conditions of Si. The second group consists of the copper group elements, including Cu, Ag, and Au, which display higher particle density than the first group and are independent of pretreatment. The size of deposited particles decreases from hundreds nm to tens nm as the particle density increases. Moreover, the displacement deposition of the Pt and Ag particles onto n-Si are in progressive and instantaneous nucleation modes, respectively.     

还原消除NOx的几类催化剂

综述了几类新型的NOx消除（De-NOx)催化剂：活性炭催化剂、负载型贵金属（Pd、Pt、Ag等）、水滑石类化合物等,它们可有效应用于NOx的催化消除。     

CHARACTERISATION OF METALFIX-CHELAMINE AND ITS APPLICATION IN PRECIOUS METAL ADSORPTION

ABSTRACT

The physical and chemical characteristics of the chelating resin Chelamine, which contains a pentamine ligand, are investigated in order to consider its application in the separation of precious metals- Adsorption isotherm experiments for Pt, Pd and Au and kinetic experiments were carried out under batch procedures. The resin presents a high level of adsorption selectivity for Pt(IV), Au(III) and Pd(II) giving a capacity of 2.8 mmol/g, 3.1 mmol/g and 2.0 mmol/g respectively. Acidic solutions, complexing agents, lipophilic anions and ammonia were used for metal elution. NaClO₄ solutions are the most effective eluting agents for Pt(IV) while thiourea is the best stripping agent for both Pd(II) and Au(III). Selective separation of the three metals can be achieved by sequential elution from the resin with NaClO₄ solutions in different HCl concentrations and thiourea 0.5 M.     

Electrolyte solutions in liquid ammonia—IX. Electrodeposition and electrodissolution of metals from their salts

Anodic dissolution and cathodic deposition of 20 transition metals in acidic solutions in liquid ammonia has been surveyed. The early transition metal elements Ti, Zr, V Nb, Mo and W form high oxidation-state insoluble amido complexes during anodic oxidation. Soluble ammines of normal metal oxidation states are produced with Cr(III), Mn(II), Fe(II), Co(III), Ni(II), Cu(II), Ag(I), Zn(II), Cd(II) and Hg(II) (Mn dissolves spontaneously). The metals Ru, Pd, Pt and Au only dissolve slightly after prolonged electrolysis. Anodic enrichment of Au in its alloys is unlike that in aqueous solution; in ammonia both Cu and Ag can be simultaneously depleted from a 9 carat gold alloy. Cathodic reduction of metal-bearing solutions follows wide variations of behaviour. Fe and Ru ammines reduce to amido-complexes with concomittant hydrogen evolution, but Cr is not reduced. Solutions of Mn, Co, Ni, Pd, Pt, Ag, Au, Zn, Cd and Hg give metallic cathode deposits under differing conditions. Electrodeposition is potential dependent for Ni, Cu and Ag; metal plate at low potentials, and powders at high potentials. The two different products are the result of reduction of species with different degrees of solvation.     

The Application of 2,6-Bis(4-Methoxybenzoyl)-Diaminopyridine in Solvent Extraction and Polymer Membrane Separation for the Recovery of Au(III), Ag(I), Pd(II) and Pt(II) Ions from Aqueous Solutions

The work describes the results of the first application of 2,6-bis(4-methoxybenzoyl)-diaminopyridine (L) for the recovery of noble metal ions (Au(III), Ag(I), Pd(II), Pt(II)) from aqueous solutions using two different separation processes: dynamic (classic solvent extraction) and static (polymer membranes). The stability constants of the complexes formed by the L with noble metal ions were determined using the spectrophotometry method. The results of the performed experiments clearly show that 2,6-bis(4-methoxybenzoyl)-diaminopyridine is an excellent extractant, as the recovery was over 99% for all studied noble metal ions. The efficiency of 2,6-bis(4-methoxybenzoyl)-diaminopyridine as a carrier in polymer membranes after 24 h of sorption was lower; the percentage of metal ions removal from the solutions (%R_s) decreased in following order: Ag(I) (94.89%) > Au(III) (63.46%) > Pt(II) (38.99%) > Pd(II) (23.82%). The results of the desorption processes carried out showed that the highest percentage of recovery was observed for gold and silver ions (over 96%) after 48 h. The results presented in this study indicate the potential practical applicability of 2,6-bis(4-methoxybenzoyl)-diaminopyridine in the solvent extraction and polymer membrane separation of noble metal ions from aqueous solutions (e.g., obtained as a result of WEEE leaching or industrial wastewater).