A rapid electrochemical method for measuring the concentration of active glue in copper refinery electrolyte which contains thiourea

Good cathode quality in copper electrorefining depends on maintaining an optimum level of glue and other leveling reagents in the electrolyte. A rapid electrochemical method has been developed for measuring the concentration of active glue in the electrolyte. It is based on the fact that glue strongly influences the polarization (currentvs potential) curve of a copper cathode in such electrolyte. The polarization curve is also influenced by the concentrations of copper, nickel, and thiourea (another leveling reagent) in the solution; the concentrations of these substances also can vary. With the present method a cathodic scan curve of a copper electrode is measured in the fresh, test electrolyte and again after the electrolyte is heated such as to destroy the active glue by hydrolysis; the heating does not affect the thiourea, Cu⁺² or Ni⁺² ions. The glue concentration is determined from the difference in the scan curves for the fresh and heated electrolytes. The difference may be quantified if needed by making standard glue additions to the cooked electrolyte and measuring the corresponding scan curves. The methods given by Refs. 2 and 4 are useful, despited the limitations stated, for tankhouse application in which Ni⁺² and Cu⁺² ion concentrations change very little or are monitored separately.     

铜电解液高As自净化工业实践

采用高砷电解液生产高纯阴极铜,两年的生产实践表明,当铜电解系统电解液中As控制在11～12 g/L时,Sb和Bi分别稳定在0.8～0.9 g/L、0.15～0.2g/L之间,As、Sb、Bi自净化脱除率分别为78.75%、94.77%、95.98%。同时,高砷电解对阴极铜质量、A级铜产出率、电解直流电单耗、添加剂单耗均无显著影响。电解液高As电解,大部分杂质锑铋以自净化形式进入阳极泥和过滤渣,电解液中积累的杂质量大量减少,计算表明原电积净化系统处理能力提高30%,净液量减少61.54%,直流电单耗下降15%,经济效益显著。     

Electrometallurgy of copper refinery anode slimes

High-selenium copper refinery anode slimes form two separate and dynamically evolving series of compounds with increasing electrolysis time. In one, silver is progressively added to non-stoichiometric copper selenides, both those originally present in the anode and those formed subsequently in the slime layer, and in the other, silver-poor copper selenides undergo a dis-continuous crystallographic sequence of anodic-oxidative transformations. The silver-to-selenium molar ratio in the as-cast anode and the current density of electrorefining can be used to construct predominance diagrams for both series and, thus, to predict the final bulk “mineralogy” of the slimes. Although totally incorrect in detail, these bulk data are sufficiently accurate to provide explanations for several processing problems which have been experienced by Kidd Creek Division, Falconbridge Ltd., in its commercial tankhouse. They form the basis for a computer model which predicts final cathode quality from chemical analyses of smelter feed.     

Solubility limits of selenium in copper

The solid solubility limit of selenium in copper was determined experimentally ranging from 20 ppma at 675°C to 92 parts per million atomic at 900°C. These results are extrapolated to 3 ppma at 500°C and 220 ppma at the melting point of copper using thermodynamic relationships. The enthalpy and entropy of dilute solution, ΔH _Sand ΔS _S are found to be 15.1 Kcal and 5.52 e.u. respectively. The meaning of the thermodynamic quantities ΔH _S and ΔS _S is discussed.     

Electrical network analysis in an electrolytic copper refinery

A network analysis computer program, developed by Kennecott, has been applied to the operation of an electrolytic refinery tank house. Using this program, heretofore unde-fined quantitative relationships between electrolytic refining cell, section and tank house can each be studied in detail. Relationships between such variables as contact resistance, electrolyte composition, current density, and percentage of short circuits can be examined individually or collectively by a simple change of input parameters. The paper describes some of the steps taken in the development of a generalized program for electrical network analysis, and its adaptation to the specific electrical network(s) found in electrolytic refineries. The procedures used to determine the values of the various network elements in an electrolytic refinery are described in particular detail, using values obtained at Kennecott Refining Corporation's Tank House as examples. The effect of short circuits on current flow within a small electrorefining section is covered briefly. Other potential areas of application, some of which have already been implemented, are also mentioned.     

Glue analysis and behavior in copper electrolyte

Animal glue in combination with other chemicals is often used as a leveling agent in the copper electroplating industry. The control of the glue concentration in the electrolyte is critical to the quality of copper produced. A quantitative galvanostatic technique for glue analysis in copper electrolyte containing lignin sulfonate and Cl⁻ was developed. The kinetics of glue hydrolysis in industrial electrolytes was studied and found to follow first-order reaction kinetics, with sulfuric acid acting as a catalyst. The dependence of the glue hydrolysis rate constant on temperature follows the Arrhenius equation. By adding fresh glue to the electrolyte, the glue activity first rises and then falls. This effect can be explained by the presence of long-chain molecules in the glue which are less active but hydrolyze into the more active medium-sized molecules. A mathematical model of this process shows good agreement with experimental data. The bulk of the electrolyte flow in the INCO commercial electrolytic plating cell bypasses the electrodes, probably across the bottom of the cell. The electrolyte circulation between electrodes is not very intense. A simple equation for the glue concentration calculation in the cell inlet and outlet, depending on the glue addition rate, was derived. V.K. Blechta, formerly Section Leader of Process Technology, INCO Limited, is retired. Z.Z. Wang, formerly Research Scientist, INCO Limited, is Researcher, Laurentian University, Sudbury,Canada.     

Hydrogen reduction of spent copper electrolyte

The recovery of copper powder and the removal of arsenic from spent copper electrolyte by means of hydrogen reduction aimed at purifying the spent copper electrolyte were studied. About 90% of the copper in the electrolyte could be recovered in the form of pure copper powder after 20 min reduction at 180° at a hydrogen pressure of 20 kg cm^?2 (2.0 MPa). An induction period, due to slow hydrogen reduction of As⁵⁺ to As³⁺, could be eliminated as a result of the addition of copper powder as a reductant. Arsenic, antimony and bismuth in the liquor have been found to catalyze the hydrogen reduction of copper. When the copper concentration in the treated solution reached a certain low level, copper arsenide, Cu₃As₁ was formed on the surface of copper through hydrogen reduction of As³⁺ ions. This reaction was very slow and a long reaction time was required for complete removal of arsenic. Therefore, in order to purify spent copper electrolyte, some arsenic removal technique (e.g., solvent extraction) should be combined with hydrogen reduction.     

Recovery of selenium from copper anode slimes

Thermogravimetric studies were made on thin layers and spherical pellets of decopperized anode slimes. These have shown that deselenization proceeds initially by the volatilization of the free selenium content at about 360°C. At higher temperatures and under an oxidizing atmosphere, silver selenide is decomposed either directly or via the formation of silver selenite and its subsequent decomposition. The rates of these reactions depend greatly on the concentration of selenium dioxide in the atmosphere over the reacting surface. It has been shown that the deselenization of slime pellets is enhanced when a forced air flow over the reacting particle is provided. This will promote oxidation, remove the selenium dioxide product to minimize the formation of silver selenite from silver and selenium dioxide, and increase the rate of decomposition of the silver selenite formed.     

铜电解液自净化研究进展

在铜电解过程中,粗铜中的有害杂质(主要是As、Sb、Bi)通过电化学溶解进入电解液并不断富集,从而严重危害阴极铜的质量及电解生产,电解液及时净化对阴极铜质量有着重要的意义.针对现行的铜电解液净化工艺中存在的能耗高、污染大、除杂效率低等缺点,对铜电解液自净化工艺进行了评述,详细介绍了目前国内外自净化除杂的实验室研究、工业应用及自净化机理的研究现状,并对其发展前景进行了展望.     

分子识别技术(MRT)在铜精炼中的应用—从铜电解液中除铋

在世界经济中,高纯电解铜是一种重要的商品,主要用来生产铜线。全球冶炼厂处理来自不同产地的矿石,生产出高纯电解铜。这些铜精矿通常含有0.1%的铋。如果最终产品中的铋含量超过2×10^-6,会导致产品出现脆性,使得铜产品不适合用于拉丝生产。IBC先进技术有限公司开发出一种有效的除铋系统,用于分离铜电解液中溶解的铋,使铋含量达到一个理想的水平。该系统与铜生产系统一体化,可实现连续作业。IBC采用一种分子识别技术（MRT）工艺来进行分离作业。在该工艺中,专门设计的螯和剂或配位体与固体骨架（例如硅胶）进行化学结合,产生一种称为SuperLig^的固相系统。这套除铋系统已经用于几家电解厂的铜精炼生产中。本文介绍了从铜电解液中分离和回收铋的工艺步骤,这些工艺步骤包括:吸收、一段洗涤、预解吸、主要解吸、后解吸、二段洗涤、铋沉淀,给出了每个步骤控制和监测的项目。本文讨论了采用其它技术控制铋的局限性。作者还介绍了MRT系统为铜电解厂带来的经济效益,这些铜电解厂都存在铋的问题。     

PLC在铜电解液循环系统中的应用

叙述了PLC在电解液循环系统高位槽液位、温度、流量控制中的应用,详细介绍了控制原理、系统结构和网络拓扑结构、重要控制回路以及现场仪表的选型。     

铜箔电解液中砷的测定

研究了乙基罗丹明B -砷钼杂多酸 -阿拉伯树胶显色体系 ,提出了测定痕量砷的高灵敏分光光度法。由于形成吸附性缔合物 ,表观摩尔吸光系数高达 3.3 2× 10 5。缔合物最大吸收位于 5 88nm ,本法用于铜箔电解液中痕量砷的测定 ,得到满意结果     

快速碘量法测定湿法冶炼电解液中的铜

对赞比亚穆利亚希湿法炼铜厂冶炼过程中的电解液组分进行了分析,发现对碘量法干扰严重的砷、锑质量浓度极低,因此采用了直接分取电解液2 m L,用氨水调节p H值至3~4的弱酸性溶液后,二价铜离子与碘离子作用生成碘化亚铜沉淀并析出适当的碘,以淀粉为指示剂,用硫代硫酸钠标准溶液滴定。该方法省去了硝酸-硫酸加热蒸干以及溴水去除砷、锑的过程,大大缩短了样品分析的时间,经与加入硝酸-硫酸及盐酸溴饱和溶液加热蒸干处理后的碘量法滴定比对,测定结果令人满意。该方法简单快速,分析结果稳定,能够满足湿法冶炼电解液中铜的生产监控要求,现已应用于赞比亚穆利亚希湿法炼铜厂的生产现场。     

197Au Mössbauer study of copper refinery anode slimes

Copper refinery anode slimes are abundantly produced during the electrolytic refining of copper. Although the slimes contain significant and economically recoverable amounts of gold and silver, the chemical state of the gold has not been fully identified. In the present work, the chemical form of gold in a copper anode, in a raw slime, and in slimes treated by different leaching procedures has been investigated by Mössbauer spectroscopy with the 77.3 keVγ-rays of¹⁹⁷Au. The Mössbauer spectrum of the anode is typical of a dilute Au:Cu alloy. The spectrum of the raw slime consists of two components, namely, a single, rather broad line with an isomer shift (IS) of about ?0.3 mm/s relative to a Pt metal source and a quadrupole doublet with an IS of + 1.2 mm/s and a quadrupole splitting of 5.0 mm/s. The single line component can be attributed to a gold-rich alloy, with an approximate composition of Au₆₀Ag{n40} or Au₈₀Cu₂₀ if it is a binary alloy, or to a ternary Au-Ag-Cu alloy of appropriate composition. The parameters of the quadrupole doublet match those of Ag₃AuSe₂ (fischesserite) or related Ag_2?xAu_xSe compounds. In these compounds, the gold atoms are coordinated by two selenium atoms in a linear arrangement, as is typical for Au(I). It was found that the ratio between the concentrations of the metallic phase and the selenide strongly depends on the leaching conditions. The measurement of the Lamb-Mössbauer factor of fischesserite is also reported.     

Electrochemical determination of thiourea and glue in the industrial copper electrolyte

An electrochemical method for determination of the thiourea and glue concentration in the industrial copper electrolyte has been developed. This method is based on changing of the copper cathode polarization potential. The amount of polarization potential change in the presence of glue and thiourea is not the sum of potential changes caused by the presence of each of those reagents separately. Thus, before determining the concentration of one component, the other component should be removed from the solution. Thiourea is removed by addition of H₂O₂ and glue—by hydrolysis at 60 °C for seven hours.     

铅锌硒在镍电解液固体杂质中的形态分析

镍电解液的品质直接影响电镍的产品质量,镍电解液中除了含有可溶的离子态杂质外,还含有不可溶的固体颗粒杂质。对固体颗粒的性质、形态和来源的研究有助于为镍电解液品质的提高提供理论依据。以固体颗粒中的微量元素铅、锌和硒作为研究对象,分别采用透射电镜、拉曼光谱、傅里叶变换红外光谱和X射线粉末衍射等物理表征方法研究固体颗粒的形态结构;利用Tessier连续提取法对3种微量元素在固体颗粒中的具体形态进行化学剖析。实验表明,该类固体主要由镍、铜、铁、硅的碱式盐、碳酸盐、硫酸盐或复盐形式存在,微量元素铅和锌主要以碳酸盐态和铁/锰态存在,而硒则以可溶态和铁/锰态存在。因此,该类固体颗粒来源于镍电解液的净化段而非来源于同槽工作的阳极液的反扩散。     

利用海带粉回收铜电解废液中铜的试验研究

研究海带粉对铜电解废液中Cu^2 的吸附行为实验表明：海带粉的最佳投加量为1．5g／l;在摇床转速为120r／min,温度为25℃,吸附时间60min,最佳pH为4～7条件下,对[Cu^2 ]=80mg／L的模拟废电解液进行吸附,最大吸附率为97．8％．实际废水的处理结果表明：对废电解液中Cu^2 吸附率达到99．5％,可达标排放．     

Glucagon increases medullary interstitial electrolyte concentration in rat kidney

In anesthetized rats, tissue electrical admittance of the inner medulla (a measure of total ion concentration in the interstitium), medullary blood flow (laser Doppler technique), and renal clearances were measured simultaneously before and during i.v. infusion of glucagon at 110 and 330 ng.min-1.kg-1 body weight. Admittance increased modestly, 5.4% after a large glucagon dose (p < 0.01), whereas medullary blood flow was stable. Glomerular filtration rate increased transiently and then fell during high-dose glucagon infusion. The increase in tissue electrolyte (mostly NaCl) concentration in the medulla observed with stable medullary blood flow and decreasing glomerular filtration rate indicates that stimulation of NaCl reabsorption in the medullary ascending limb of Henle's loop by glucagon was the mechanism underlying augmentation of medullary ionic hypertonicity. This suggests that glucagon can contribute to the urine concentration process.     

Mineralogical characterization of a copper anode and the anode slimes from the la caridad copper refinery of mexicana de cobre

A detailed mineralogical study was carried out to characterize a copper anode, the anode-face slimes, the slimes on the bottom of the refining cell, and the autoclave-leached slimes from the La Caridad refinery of Mexicana de Cobre. The objective was to identify possible Pb-Sb-Bi and As-Sb-Bi interactions that could control the Sb and Bi concentrations of the electrolyte. Although some Pb, As, Sb, and Bi can be found in solid solution in the copper crystals of the anode, these elements are mostly present as Cu-Pb-As oxide and Cu-Pb-As-Sb-Bi oxide inclusions at the grain boundaries. During electrorefining, the Pb, As, Sb, and Bi in solid solution dissolve. Part of the Pb, As, Sb, and Bi in the oxide inclusions also dissolves, but part reacts in situ to form PbSO₄ and Pb₅(AsO₄)₃(OH,Cl). Some of the dissolved elements reprecipitate as PbSO₄, SbAsO₄, Sb-As oxide, Sb-As-Bi oxide, Pb₅(AsO₄)₃(OH,Cl), and an oxidate phase of mainly Cu-Ag-AsO₄-SO₄ composition. Thus, high As contents facilitate the precipitation of Sb and Bi from the electrolyte. Although Pb-Sb oxide and Pb-Bi oxide species were only rarely detected, a high Pb content in the anode may retard the dissolution of the Cu-Pb-As-Sb-Bi oxide inclusions, thereby retaining some Sb and Bi in the raw anode slimes. Autoclave leaching dissolves part of As, Sb, and Bi, but the SbAsO₄ and Sb-As-Bi oxide species remain in the leach residue. The Pb is converted almost entirely to PbSO₄, which is present as subhedral crystals in the autoclave leach residue.