铜—镍—铬（镍铁—铬）镀层酸性电解退镀液

对５种不同钢铁基体的光亮镀镍，镍铁合金镀层进行退镀。分析了退镀液想方中ＳＴ－１添加剂含量，ｐＨ值，温度，电流密度对退镀速度和基体腐蚀的影响。退镀液的ｐＨ值为３．５－５．５。     

铜－镍－铬（镍铁－铬）镀层酸性电解退镀液

对５种不同钢铁基体的光亮镀镍、镍铁合金镀层进行退镀。分析了退镀液配方中ＳＴ－１添加剂含量、ｐＨ值、温度、电流密度对退镀速度和基体腐蚀的影响。退镀液的ｐＨ值为３．５～５．５。     

退除铜及黄铜工件上镍镀层的“退镍粉”

介绍了一种退除铜及黄铜工件上镍镀层的退镍粉配方(以配制l kg为例):六水合硫酸镍30 g,硫酸钠435 g,硫氰酸铵30 g,苯并三氮唑5 g,防染盐S(间硝基苯磺酸钠)500 g.退镀液的组成及操作条件为:退镀粉120g/L,浓硫酸60 mL/L,温度25～ 75℃,机械搅拌.退镀流程主要包括化学除油、退铬、退镍和除黑膜.介绍了退镀液的配制及维护方法.     

高碳钢基体退镀工艺

1　概述镀镍 铬金属层 ,在高碳钢材料的保护方面应用十分广泛。不合格镀层约占 3%～ 8% ,需要及时退除 ,否则 ,影响基体防腐能力或产品的装饰性能 ,降低产品的合格率。目前 ,由于诸多原因 ,高碳钢基体上不合格镀层的退除以化学法为主 ,该法工艺简单 ,但操作环境恶劣 ,污染严重。电解法能够保证高碳钢基体的退镀效果 ,而且克服化学法退镀的众多弊病。2　电解退镀我们运用了电化学、精细化工等多门类、多学科知识 ,参阅大量国内外有关文献 ,开发研制成功ＪＳ986系列高碳钢基体电解退镀添加剂。该添加剂经小试、中试后 ,已应用于退镀生产线 ,…     

响应面优化废弃ABS镀件退镀工艺研究

采用硫酸-过氧化氢混合液对废旧ABS电镀件进行退镀处理,研究了硫酸浓度、过氧化氢浓度、液固比和浸泡时间对退镀率的影响。在单因素试验的基础上,通过响应面实验设计优化工艺条件。结果表明,四个因素对影响次序为:过氧化氢浓度硫酸浓度液固比时间,硫酸浓度与液固比的交互作用影响显著,最佳的退镀条件是:硫酸浓度(A)为16%,双氧水浓度(B)为4%,时间(C)为2 h,液固比(D)为14. 75,在此工艺条件想退镀率为94. 4%。     

水晶磨盘再生处理-基于铁基上电解退镀镍电解液研究

结合水晶磨盘的结构特点,开发了一种以硫酸、甘油、双氧水为组要成分的新型电解退镀液,考察了各反应参数对镍的退镀速率和铁蚀速率的影响,结果表明,最佳的电镀液成份为硫酸浓度500 m L/L,甘油浓度25 m L/L,双氧水浓度20 m L/L,反应温度为35℃,槽电压控制在5 V时,镍的退除速率达到19.2μm/h,铁蚀速率为0.1μm/h。     

装饰镀铬层退镀工艺探讨

装饰镀铬层退镀工艺一直是生产难题之一.近几年,人们从添加剂和机理方面深入研究,出现了较先进的退镀工艺,特别铜—镍(或镍铁)—铬一次性退镀的工艺已有所进展.本文就退镀的基本原理及实用工艺作一粗试的探讨.一、退镀的原理与工艺选择1.退镀的基本过程退镀可分用化学和电解两种方法.化学退镀的实质是利用有氧化活性的氧化剂将退镀金属氧化为金属离子,络合剂将游离金属离子络合,以降低界面及溶液本体中的金属离子,从而维持一定的化学势,使界面反应进行,在镀层退除并露出基体金属时,缓蚀剂以某种形式吸     

NdFeB磁体表面镀铝膜层退镀液配方的研究

用NaOH作腐蚀剂,添加辅助盐、表面活性剂、配位剂和缓蚀剂,研制了一种高效稳定的NdFeB表面镀铝膜退镀液。以Nd Fe B试样表面的铝含量和基体失重量作为性能评定指标,通过正交试验确定了优化的退镀液配方为:NaOH 10 g/L,Na_2CO_3 30 g/L,十二烷基苯磺酸钠6 g/L,EDTA-2Na 4g/L,六次甲基四胺4 g/L。优化的退镀液在室温条件下退镀3 min,即可把NdFeB基体上约12μm厚的铝膜退除干净,而且退镀后基体的剩磁、矫顽力和最大磁能积仅分别变化1.27%、1.25%和0.47%,磁性能损伤较小。探讨了NdFeB表面镀铝膜层的退镀机理。     

浅谈黄铜基体上镍铬镀层的退镀

讨论了退镀速度和防止基体受腐蚀问题,建议选用硫酸介质电解退镀.     

常用退镀方法

常用退镀方法胡光军１、镀锌层２、镀铜层３、镀金层４、镀银层５、镀铬层安徽蚌埠市无线电四厂（邮编２３３０００）６、镀镍层７、镀铅层８、镀锡层常用退镀方法@胡光军$安徽蚌埠市无线电四厂...     

铝合金件喷涂层剥落故障的处理

分析了铝合金件喷涂层出现剥落的原因并提出了解决方法。     

Interaction of Pb and Cd during anodic stripping voltammetric analysis at boron-doped diamond electrodes

Highly boron-doped diamond (BDD) films were utilized for simultaneous electrochemical measurement of micromolar-level concentrations of Pb and Cd, and for the examination of their interactions. Differential pulse anodic stripping voltammetry (DPASV) was used for this detection. This approach can help to understand the possible detection of trace metals at BDD electrodes without the aid of mercury. These metals were found to strip at their characteristic potentials, in solutions containing Cd or Pb alone, and in those containing these metals together. The mixed solutions (concentration range: 1-5 μM) yielded well-separated stripping peaks for Pb and Cd and the differential stripping peak currents for the respective metals increased linearly with increasing metal concentration. There were mutual interferences due to Pb-Cd interactions, but these can be taken into account with the aid of three-dimensional calibration plots. A model has been developed to help explain the Pb-Cd interactions.     

Recovery of copper from ammoniacal/ammonium sulfate medium by LIX 54

The extraction‐stripping reaction of Cu(II) by LIX 54 in Iberfluid from aqueous ammonium sulfate medium at pH 8.5 has been investigated. The effects of pH, metal ion, extractant concentration as well as the loading capacity of the reagent were studied. The extraction equilibrium constant for copper was determined numerically to be 7 × 10⁻⁷. Experimental data can be explained assuming the formation of CuR₂ species in the organic phase (R represents the extractant). Copper stripping was studied using typical spent copper electrowinning solutions as stripping medium. The number of stages required for the extraction and stripping of copper was also evaluated. The results were used to asses the conditions for purification of industrial waste solutions (eg spent etchants) containing copper through counter‐current extraction‐stripping. © 1999 Society of Chemical Industry     

利用超声波阳极溶出伏安法测定痕量汞

以阳极溶出伏安法研究了超声波作用下汞在金电极上的电化学行为,建立了痕量汞的超声波-阳极溶出伏安法。采用超声波增加了汞的溶出峰电流,提高了方法的灵敏度,在优化实验条件下,汞离子浓度在0～25μg/L范围内,线性方程为I=1.08c+0.27,(μg/L,R=0.998),加入标准汞溶液为6μg/L时,测量值的重复性和精确度都在5%以内。常见金属离子一般不干扰,方法简便快速。     

Silver electrowinning from silver(I)–calixarene complexes by two-phase electrolysis

Results are reported, providing the basis for an elegant new process for metal recovery from acidic solutions, by integrating solvent extraction (SX) and electrowinning (EW) in a single process, rather than operating them separately, as in conventional SX–EW processes. Calixarene-tetramide and its thio-analogue were used for the extraction of silver(I) ions from aqueous phases into dichloromethane, both compounds achieving extraction efficiencies >90%. The effects were determined of extractant and silver(I) concentrations, aqueous phase pH, and the presence of sodium ions, on the distribution of Ag(I) between aqueous and organic phases. Due to the impossibility of stripping the extracted metal conventionally, electro-reductive stripping of silver(I) from the loaded organic phase was carried out in the calixarene/nitric acid two-phase system. The effects were also investigated of current density or electrode potential on silver deposition current efficiencies and cell voltages. Based on experimental data, a new process for silver(I) removal from very dilute solutions was proposed that showed high percentage extractions of silver(I) from the aqueous phase, coupled to direct EW of silver from the calixarene complex in the loaded organic phase, regenerating the extractant for recycle. Current efficiencies in the range from 60% to 90% and cell voltages <3.5 V were achieved simultaneously in this process.     

Extraction and separation of molybdenum(VI) from acidic media by fatty hydrazides

BACKGROUND: The increasing demand for molybdenum has encouraged the development of low‐cost and environmentally friendly extractants to recycle and recover this metal. In the present study, solvent extraction of Mo(VI) from acidic media using a mixture of fatty hydrazides synthesised from palm olein as the extractant was carried out. The effects of various parameters such as acid, diluent, contact time, extractant concentration, metal ion concentration and stripping agent and the separation of Mo(VI) from other metal ions such as Co(II), Ni(II), Al(III) and Mn(II) were investigated. RESULTS: It was found that the extraction of Mo(VI) into the organic phase involved the formation of 1:3 complexes. Mo(VI) was successfully separated from commonly associated metal ions such as Ni(II), Co(II), Al(III) and Mn(II). Mo(VI) stripping from the loaded organic phase was studied using different acidic and alkaline solutions and was found to be optimal with ammonium hydroxide solution. CONCLUSION: These results are useful for the development of a method to recover Mo(VI) from acidic media utilising fatty hydrazides as the extractant. Copyright © 2008 Society of Chemical Industry     

烧结型钕铁硼镀镍层退除工艺的研究

研究对比了三种钕铁硼镀镍层退除工艺的退除速度及基体腐蚀情况.筛选出硫酸铜一硫酸电解液电解退除镀镍层为较优方法,确定了最佳组成为硫酸650 mL/L、硫酸铜25g/L、电解电压6 V.探讨了退镀原理及影响退镀的各种因素.结果表明:电压是影响退镀的主要因素,其次是硫酸和硫酸铜的含量.该配方退镀速度较快、成本低、对基体腐蚀小、使用寿命长,适合NdFeB永磁体镍镀层的退除,也适合铁基精密零件镍镀层的退除.     

Controlled stripping of aluminide coatings on nickel superalloys through electrolytic techniques

Aluminide diffusion coatings are widely employed to improve the oxidation and/or the corrosion resistance of highly added value turbine components operating in harsh environments at high temperatures. Refurbishment of such components requires appropriate removal of worn coatings and of the corrosion products layer—usually an oxide scale. Stripping is mostly carried out using hazardous chemical baths of limited reliability. In this work, an alternative stripping method based on electrochemical techniques has been carried out at laboratory scale for CVD Al diffusion coatings on a directionally solidified Ni base superalloy. Both the galvanostatic and the potentiostatic modes have been investigated. Prior to them, in situ gas bubbling induced by cathodic polarization seems to be an effective way to remove the superficial oxide scales. Measuring the open circuit potential during the experiments allows easy monitoring of the progress of the selective dissolution of the different layers. Complete removal of the aluminide coatings is indicated by potential values similar to those of the substrate. The correlation between the electrochemical features and the surface state after stripping has been carried out by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). The electrochemical approach is a promising means to strip out surfaces in a selective and reliable manner.     

酸性水汽提装置增上氨精制系统运行效果

本酸性水汽提装置原来采用单塔加压蒸汽汽提工艺,大检修时改造为单塔汽提侧线抽氨工艺.增加抽氨工艺后的装置运行情况基本良好,具有显著的经济、社会和环境效益.分析了运行中存在的问题并提出了解决问题的建议.     

Stripping of Au(I) from a Loaded Cetyltrimethylammonium Bromide/Tributyl Phosphate Organic Solution: Conversion and Reduction

The recovery of Au(I) from cyanide leaching solutions by solvent extraction techniques has attracted wide interest in the past decades. However, no substantial progress in industries has been reported yet, because of the difficulties concerning gold stripping from loaded organic phases, such as the quaternary amines extraction systems. In this work, a new technique for the recovery of Au(CN)₂ ^? from the loaded cetyltrimethylammonium bromide / tributyl phosphate organic solution by a two‐step stripping procedure is suggested first by Au(CN)₂ ^? conversion by HCl into corresponding chloride complex ions, and then by chemical reduction of auro‐chloride complex ions in TBP organic phases to give metal gold powder. The influences of HCl concentrations, reaction time, and various reducing agents used on the percent gold conversion and reduction were investigated. About 33% of Au(CN)₂ ^? in the initial TBP organic phase could be precipitated as metal gold powder in the conversion step, while 67% was converted into AuCl₂ ^? or AuCl₄ ^? and held in the organic phase. Subsequently, the loaded organic phase after conversion was contacted with reducing agents such as sodium sulfite, ammonium oxalate, or hydrazine hydrate. Most (>98%) of the auro‐chloride complex ions could be effectively reduced as metal gold. As a result, the total gold recovery from the initial TBP organic phases after the two stripping procedures achieved more than 98%. The ¹⁹⁸Au radioactive tracer was employed to determine the concentration and distribution behavior of gold in both organic and aqueous solutions. In addition, the experiment on the reuse of the organic phase after gold stripping showed that there was no obvious loss in percent gold(I) recovery after one cycle of the extraction‐ stripping‐ regeneration process no matter what reducing agent was used.