Separation and recovery of Ni from copper electrolyte by crystallization of nickel ammonium sulfate double salt

The separation and recovery of Ni from the copper electrolyte by crystallization of nickel ammonium sulfate double salt were studied. It is found that the solubility of copper sulfate at the same temperature is less than that of nickel sulfate, while the solubility of copper ammonium sulfate is greater than that of nickel ammonium sulfate. So, by adding (NH₄)₂SO₄, the Ni can be selectively crystallized from the copper electrolyte. By adding (NH₄)₂SO₄ at the molar ratio of (NH₄)₂SO₄/NiSO₄ ≤0.8, and crystallizing at —15 °C for 10 h, the Ni in the copper electrolyte can be crystallized in the form of Ni(NH₄)₂(SO₄)₂·6H₂O. The qualified product of NiSO₄·6H₂O can be obtained by pyrolyzing the crystals, dissolving the pyrolysis product in water, and then concentrating the dissolved solution for crystallization. The method of double salt crystallization is a clean, environmentally-friendly, cost-effective and efficient method for separating and recovering nickel from copper electrolyte.     

Breaking the purity-stability dilemma in pure Cu with grain boundary relaxation

High purity metals are increasingly demanded in modern manufacturing industries, but their processing and applications are limited by a dilemma that purer metals are thermally and mechanically less stable. The reduced stability of pure metals originates from the weakened drag effect of impurity atoms on the mobility of grain boundaries (GBs) that are hard to stabilize without alloying. Following recent studies on stabilizing nanograined metals by tailoring structures of GBs, here we report that structural relaxation of GBs breaks the purity-stability dilemma in pure Cu. Contrary to the conventional impurity effect, thermal stability and hardness of nanograined Cu samples with relaxed GBs increase (rather than decrease) with higher purities. The discovered anomalous impurity effect, owing to suppression of GB relaxation process with impurity atoms, offers an alternative vector to stabilizing purer metals for advanced processing and applications.     

X射线荧光光谱在铜矿石分析中的应用文献评介

作者收集了我国用X射线荧光光谱(XRF)分析技术进行铜矿石(含铜精矿)分析的文献共计51篇,其中野外现场分析文献21篇,实验室内分析文献30篇。实验室内方法文献包括熔融制样法12篇,粉末压片制样的15篇,其他方法3篇。文章用列表方式对文献要点进行了介绍,对其中的多元素分析方法文献进行了重点评介,也特别讨论了X射线荧光光谱分析的技术条件、制样方法选取、标准物质与标准方法等问题。文献表明:XRF已成为铜矿石主次痕量分析最强有力的技术方法之一,并随着社会对环境需求的增长,直接粉末压片制样的XRF方法必将具有更广阔的发展前景。全篇引文89篇。     

Computational Investigation of Effects of Grain Size on Ballistic Performance of Copper

Numerical simulations were conducted to compare ballistic performance and penetration mechanism of copper (Cu) with four representative grain sizes. Ballistic limit velocities for coarse-grained (CG) copper (grain size ≈ 90 µm), regular copper (grain size ≈ 30 µm), fine-grained (FG) copper (grain size ≈ 890 nm), and ultrafine-grained (UG) copper (grain size ≈ 200 nm) were determined for the first time through the simulations. It was found that the copper with reduced grain size would offer higher strength and better ductility, and therefore renders improved ballistic performance than the CG and regular copper. High speed impact and penetration behavior of the FG and UG copper was also compared with the CG coppers strengthened by nanotwinned (NT) regions. The comparison results showed the impact and penetration resistance of UG copper is comparable to the CG copper strengthened by NT regions with the minimum twin spacing. Therefore, besides the NT-strengthened copper, the single phase copper with nanoscale grain size could also be a strong candidate material for better ballistic protection. A computational modeling and simulation framework was proposed for this study, in which Johnson–Cook (JC) constitutive model is used to predict the plastic deformation of Cu; the JC damage model is to capture the penetration and fragmentation behavior of Cu; Bao–Wierzbicki (B-W) failure criterion defines the material's failure mechanisms; and temperature increase during this adiabatic penetration process is given by the Taylor–Quinney method.     

钽表面铜掺杂Ta2O5纳米棒的制备及抗菌性能研究

本实验采用两步水热法在钽基体表面制备出掺杂Cu_²⁺的Ta₂O₅纳米棒薄膜。采用XRD、SEM、XPS等方法分析了材料的物相和表面微观结构。用ICP检测了样品在生理盐水中离子析出浓度,最后通过平板计数法检验了不同含量铜掺杂Ta₂O₅薄膜的抗菌能力。结果表明,通过两步水热处理,在钽表面生成了简单斜方晶体结构的Ta₂O₅纳米棒阵列,Cu_²⁺的掺杂不会对纳米棒薄膜的微观形貌和物相造成显著影响。随时间的增加,掺铜薄膜的铜离子析出速率逐渐趋于平缓。平板计数法表明,Cu_²⁺ 的掺杂量达到2.68At%时,铜掺杂Ta₂O₅纳米棒薄膜的抗菌性能最好,抗菌率达99.2%。     

Preparation and characterization of polyvinylchloride membrane embedded with Cu nanoparticles for electrochemical oxidation in direct methanol fuel cell

Copper nanoparticles were prepared by the chemical reduction method. These copper particles were embedded into the polyvinylchloride (PVC) matrix as support and used as an electrode (PVC/Cu) for the oxidation of methanol fuel for improving the current response. The PVC/Cu electrodes were characterized by thermal gravimetric analysis (TGA) for thermal stability of the electrode, X-ray diffraction (XRD) for identification of copper nanoparticles in the electrode, Fourier transform infrared spectroscopy (FTIR) to identify the interaction between PVC and Cu and scan electron microscopy (SEM) with EDAX for the morphology of the electrode. The electrocatalytic activity of the electrode was characterized by the cyclic voltammetry, linear sweep voltammetry, and chronoamperometry techniques. An increase in the electrode activity was observed with the increase of copper quantity from 0.18 g (PVC/Cu-0.18 g) to 0.24 g (PVC/Cu-0.24 g) and the maximum was found at 0.24 g of copper in the electrode. Also, it was observed that the electrode achieved the maximum catalytic current in 0.5 mol/L CH₃OH + 1 mol/L NaOH solution. FTIR identified that water molecules, C—H group, copper nanoparticle and its oxide were available in the electrode. SEM images with EDAX showed that copper particles were properly embedded in the polyvinylchloride matrix.     

Scandium recovery from raffinate copper leach solution as potential new source with ion exchange method

Raffinate copper leach solution of the Iran Sarcheshmeh copper complex has up to 3 mg/L scandium (Sc), which is significantly better than many existing sources, making it a possible source for the recovery of Sc using the ion exchange method. Visual Minteq software was employed to ascertain the ionic species likely to be formed under operational conditions in the mine and for selecting the suitable ion exchange resin. The cationic resin thus chosen was employed statically with ions-bearing synthesized solutions and statically/dynamically for actual copper mining raffinate solution. Room temperature and pH of 1.5 showed the highest Sc adsorption. The dynamic tests established the full saturation of the resin at 450 BV of the raffinate solution flow. Using sodium carbonate for elution, desorption of Sc, Y and Ce from the resin during static elution tests at constant duration was higher than that of Fe, Al and Cu. The results from the dynamic tests followed similar trends for the priority and the extent of the elution process. Desorption results from specimens of dynamic tests show a 60:1 concentration ratio leading to a 186 mg/L Sc-rich solution.     

Detailed Insight into the Interaction of Bicyclic Somatostatin Analogue with Cu(II) Ions

Somatostatin analogues are useful pharmaceuticals in peptide receptor radionuclide therapy. In previous studies, we analyzed a new bicyclic somatostatin analogue (BCS) in connection with Cu(II) ions. Two characteristic sites were present in the peptide chain: the receptor- and the metal-binding site. We have already shown that this ligand can form very stable imidazole complexes with the metal ion. In this work, our aim was to characterize the intramolecular interaction that occurs in the peptide molecule. Therefore, we analyzed the coordination abilities of two cyclic ligands, i.e., P1 only with the metal binding site and P2 with both sites, but without the disulfide bond. Furthermore, we used magnetic circular dichroism (MCD) spectroscopy to better understand the coordination process. We applied this method to analyze spectra of P1, P2, and BCS, which we have described previously. Additionally, we analyzed the MCD spectra of P3 ligand, which has only the receptor binding site in its structure. We have unequivocally shown that the presence of the Phe-Trp-Lys-Thr motif and the disulfide bond significantly increases the metal binding efficiency.     

基于稳定固溶体团簇模型的无扩散阻挡Cu合金薄膜的成分设计

随着超大规模集成电路的发展,器件特征尺寸不断缩小,必然会出现Cu互连扩散阻挡层厚度无法进一步减小等瓶颈问题。因此,开发新型无扩散阻挡层Cu合金薄膜(Cu种籽层)势在必行。该新型互连结构在长时间的中高温(400~500℃)后续工艺实施过程中,需同时具备高的稳定性(不发生互扩散反应)和低的电阻率。基于此,首先综述了目前无扩散阻挡层结构的研究现状及问题,然后对基于稳定固溶体团簇模型设计制备的无扩散阻挡Cu-Ni-M薄膜的研究工作进行了梳理,通过多系列薄膜微观结构、电阻率及稳定性的对比,深入探讨了第三组元M的选择原则及其对薄膜热稳定性的影响。为进一步验证稳定固溶体团簇模型的有效性,对第二组元的变化进行了相关讨论。结果证实,选取原子半径略大于Cu、难扩散且难溶的元素作为第三组元M,薄膜表现出良好的扩散阻挡能力;当M/Ni=1/12,即合金元素完全以团簇形式固溶于Cu基体时,薄膜综合性能达到最优,能够满足微电子行业的要求。所有研究表明,稳定固溶体团簇模型在无扩散阻挡层Cu合金薄膜的成分设计方面十分有效,该模型也有望在耐高温Cu合金及抗辐照材料成分设计方面推广使用。