硝酸型废退锡水的分离特性与蒸馏强化偏锡酸回收

针对电路板硝酸型废退锡液再生和锡提取技术的改进,对硝酸型废退锡水的物理化学特征、氧化还原与沉淀反应规律、真空蒸馏特性进行了理论分析和实验研究。结果表明：硝酸溶液中三价铁离子的存在可以将锡离子氧化为四价;硝酸浓度的提高可促进β型偏锡酸沉淀的形成;蒸馏是硝酸的浓缩过程,当水的蒸出率达到67.75%时,硝酸质量分数提高到40.04%,锡的质量分数降到了0.04%。废退锡水中锡以β型偏锡酸形式析出,析出率达到97.36%。经过蒸馏强化所获得沉淀物具有更好的沉淀特性;蒸馏底液保留了退锡水的有效成分,可作为再生退锡水。     

Properties of a Tin Oxide-Base Ceramic Body

Some thermal and mechanical properties were measured for tin oxide-matrix compacts which nominally were composed of 99% by weight tin oxide (SnO₂) and 1% zinc oxide (ZnO). The sintered compacts were similar in strength to high–fire mullite porcelains, had superior resistance to thermal shock, and had high thermal conductivity. The tin oxide body might be expected to give good service under conditions of severe thermal shock and in an oxidizing atmosphere at temperatures up to 1500°F.     

Hydrolysis Deposition of Thin Films of Antimony-Doped Tin Oxide

Thin films of antimony-doped tin oxide have been obtained by a new technique, the so-called hydrolysis deposition method, in which hydrolyzed solids are precipitated from metal fluoride solutions. Mixed solutions of SnF₃ and SbF₃ produce antimony- and fluorine-doped tin oxide films. The amount of antimony can be controlled in a wide range by adjusting the initial fluoride concentrations of the solution. The film containing 2.9 mol% antimony heated at 500°C has an electrical resistivity of 1.0 × 10⁻³Ω·cm, which is lower than previously obtained by wet-chemical techniques.     

On the behaviour of tin-containing species in cryolite–alumina melts

Tin oxide (SnO2) dissolves in cryolite–alumina melts forming tetravalent tin species, but under reducing conditions it is reduced to divalent tin and, further, to metallic tin. Freezing point depression data for SnF2 and SnO in molten cryolite (Na3AlF6) corresponded to the formation of one and two new particles, respectively. By anodic dissolution of tin into cryolite-alumina melts divalent as well as tetravalent tin was formed, depending on current density and composition. During electrolysis of SnO2-based oxygen-evolving anodes, the condensate above the melt contained both divalent (SnF2) and tetravalent (SnO2) tin species.     

SURFACE TENSION AND BUOYANCY DRIVEN INSTABILITIES IN A LAYER OF LIQUID TIN HEATED FROM BELOW

The linear theory of Pearson (1958) and Nield (1964) is modified here to study liquid tin and include the finite thermal resistances of the bounding layers of boron nitride, copper and air (∼10^-2 torr) in the experiments of Ginde et al. (1989). The magnitude of the ΔT_c across the layer of liquid tin required for the onset of convection depends on the ratios of the thermal conductivities and thicknesses of the supporting layers of boron nitride and copper to those of the tin.

According to our theory surface tension contributes more than buoyancy to the instability observed experimentally. The critical ΔT_c observed required for the onset of convection in the layer of tin, is up to 25% lower than that predicted, which shows the layer is less stable than the theory indicates. Thus the surface of the tin was uncontaminated, or a significantly larger observed critical ΔT_c would be expected.

The boundary condition on the thermal fluctuations at the base of the supporting layer of copper does not appear to be important in these experiments. However, the thermal resistance of the boron nitride would have to be assumed to be unrealistically large to obtain agreement within experimental error with the theory.     

马来酸甲基锡的合成研究

以甲基氧化锡和马来酸溶液为原料,反应合成一种无硫化污染、无臭味的PVC加工热稳定剂马来酸甲基锡。研究讨论了合成反应的工艺条件对产率以及产品锡含量的影响,最佳的合成工艺条件为:(1)马来酸反应系数1.01;(2)马来酸溶液浓度为45%;(3)反应温度35℃;(4)反应时间4 h。在此工艺条件下产率最大,达97.8%以上,产品锡含量45.2%左右,与理论值较接近。     

Homogeneous Precipitation of Hydrous Tin Oxide Powders at Room Temperature Using Enzymatically Induced Gluconic Acid as a Precipitant

Hydrous tin oxide powders were precipitated at room temperature via the neutralization of sodium stannate with gluconic acid. The gluconic acid was generated by the oxidation of glucose, with the assistance of a glucose oxidase/catalase system. The hydrous tin oxide, which had a large surface area, was obtained when a high concentration of enzymes was used as a solution. However, the apparent sizes of the precipitates were ∼0.3 μm, independent of the enzyme concentration. The precipitates were converted to tin oxide via calcination at temperatures >400°C.     

Advanced Sn/C composite anodes for lithium ion batteries

Metallic tin was deposited in fine particulate form on the surface of carbonaceous mesophase spherules (CMS) and in the pores of porous carbon by the decomposition and reduction of tin(II) 2-ethylhexanoate at 450 °C. The Sn/C composite powders obtained were used as anode materials for lithium ion cells. Electrochemical cycling tests of coin cells show that the dispersion of tin into the carbonaceous materials enhances the reversible capacity of the electrodes. The capacity retention at the 50th cycle is 91 % for Sn/CMS composite containing 22% tin, against 428 mAh g^–1 at the first cycle. With further increase in tin content, the capacity fade upon cycling is more rapid.     

Transmission Electron Microscopy and Electron Energy-Loss Spectroscopy Characterization of Glass Phase in Sol-Gel-Derived Mullite

Sol-gel-derived mullite ceramics were processed by pressureless sintering at 1600°, 1650°, and 1700°C for 4 h. Microstructural and microchemical characterization of the mullite materials was performed using transmission electron microscopy, in conjunction with energy-dispersive X-ray spectroscopy and electron energy-loss spectroscopy (EELS). Apart from mullite grain diameter and triplepocket size, no major microstructural changes were observed with increasing sintering temperature. Residual glass was present at triple pockets and along two-grain junctions. Not all grain boundaries revealed the presence of a continuous amorphous intergranular film. Clean interfaces were observed only at boundaries with one grain parallel to the [001] orientation (low-energy configuration). Quantitative EELS analysis of mullite grains and glass pockets revealed only small changes in composition with increasing sintering temperature; i.e., the alumina:silica ratio slightly increased for mullite and glass. The analysis implied that mullite with this relatively high aluminum content would not be stable adjacent to residual glass. However, a stable glass-mullite system has been proposed, because impurity cations were detected within glass pockets, which suggested a slight shift of the subsolidus line (glass-mullite/ mullite) to a higher amount of alumina. Energy-loss nearedge structure studies of the Si- L _2,3 edge revealed a similar near-edge structure for the mullite, residual glass, and quartz. Thus, SiO₄ tetrahedra were thought to be the main building units of the glass contained in sintered mullite.     

痕量锡的邻苯二酚紫体系催化光度法测定

基于在0.5 mol/L的硫酸介质中,痕量锡对溴酸钾氧化邻苯二酚紫的褪色反应具有催化作用,建立了催化光度法测定痕量锡的动力学光度法。讨论了酸度,氧化剂,显色剂,反应时间,反应温度,干扰离子等因素的影响,确定了该体系反应的最佳条件为:0.5 mol/L硫酸1.5 mL;0.1 mol/L溴酸钾1.25 mL;2.0×10-4mol/L邻苯二酚紫3.5 mL;反应时间为7 min;反应温度为100℃。在最佳的条件下,方法的检出限为4.51×10-3g/mL,线性范围为0~3μg/25 mL。进行了平行测定(n=11),其相对标准偏差1.88%,该方法简便,设备简单,易于操作,并且具有较高的灵敏度和选择性。用于水样、人发中痕量锡的测定,相对标准偏差分别为0.312%和1.11%,标准加入回收率分别为99.8%和99.5%。     

A new strategy for plasticizing and stabilization of PVC mixtures

This study was undertaken to examine possible use of classic tetravalent tin‐based heat stabilizers for the preparation of a polymer plasticizer: poly(ε‐caprolactone) (PCL) and simultaneous stabilization of PVC in PVC/PCL mixtures. PCL was prepared from ε‐caprolactone (CL) by polymerization initiated by tin‐containing organic compounds and successfully used to simultaneously plasticize and stabilize PVC. Moreover, conditions under which the polymerization of CL took place directly in situ during PVC/CL mixture processing were found. The procedure yielded homogeneous plasticized PVC/PCL mixtures, which were stable and contained >90% of the original monomer content. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41066.     

Synthesis and characterization of single-crystalline zinc tin oxide nanowires

Crystalline zinc tin oxide (ZTO; zinc oxide with heavy tin doping of 33 at.%) nanowires were first synthesized using the electrodeposition and heat treatment method based on an anodic aluminum oxide (AAO) membrane, which has an average diameter of about 60 nm. According to the field emission scanning electron microscopy (FE-SEM) results, the synthesized ZTO nanowires are highly ordered and have high wire packing densities. The length of ZTO nanowires is about 4 μm, and the aspect ratio is around 67. ZTO nanowires with a Zn/(Zn + Sn) atomic ratio of 0.67 (approximately 2/3) were observed from an energy dispersive spectrometer (EDS). X-ray diffraction (XRD) and corresponding selected area electron diffraction (SAED) patterns demonstrated that the ZTO nanowire is hexagonal single-crystalline. The study of ultraviolet/visible/near-infrared (UV/Vis/NIR) absorption showed that the ZTO nanowire is a wide-band semiconductor with a band gap energy of 3.7 eV.     

Semitransparent inverted polymer solar cells employing a sol-gel-derived TiO2 electron-selective layer on FTO and MoO3/Ag/MoO3 transparent electrode

We report a new semitransparent inverted polymer solar cell (PSC) with a structure of glass/FTO/nc-TiO₂/P3HT:PCBM/MoO₃/Ag/MoO₃. Because high-temperature annealing which decreased the conductivity of indium tin oxide (ITO) must be handled in the process of preparation of nanocrystalline titanium oxide (nc-TiO₂), we replace glass/ITO with a glass/fluorine-doped tin oxide (FTO) substrate to improve the device performance. The experimental results show that the replacing FTO substrate enhances light transmittance between 400 and 600 nm and does not change sheet resistance after annealing treatment. The dependence of device performances on resistivity, light transmittance, and thickness of the MoO₃/Ag/MoO₃ film was investigated. High power conversion efficiency (PCE) was achieved for FTO substrate inverted PSCs, which showed about 75% increase compared to our previously reported ITO substrate device at different thicknesses of the MoO₃/Ag/MoO₃ transparent electrode films illuminated from the FTO side (bottom side) and about 150% increase illuminated from the MoO₃/Ag/MoO₃ side (top side).     

Leaching behaviour of tin with oxygen in recycled phenolsulfonic acid tin plating solutions

The dissolution characteristics of metallic tin with oxygen in recycled phenolsulfonic acid (PSA) tin plating bath to compensate tin consumed during the previous plating operation were investigated using electrochemical methods and leaching experiments at 30 °C. Electrochemical polarization data indicate that the diffusion of dissolved oxygen is the rate determining step and this is confirmed by leaching experiments. The sludge formed due to further oxidation of stannous ions during leaching in PSA tin plating solutions contains approximately 40 wt % Sn.     

电镀锡渣制备氯化亚锡和锡酸钠

介绍了从电镀别针厂产生的大量锡渣废料中制取氯化亚锡和锡酸钠的原理、工艺流程和工艺条件。讨论了温度、pH值和氧化剂对酸解、碱解反应的影响。实验表明 ,采用浓盐酸和氢氧化钠处理电镀锡渣的工艺流程简单 ,设备简单 ,条件容易控制 ,不但处理了大量含锡废渣 ,而且制取了合格的氯化亚锡和锡酸钠产品 ,回收率达 70 %以上 ,使电镀锡达到循环利用的目的 ,取得了明显的经济效益。     

Removal of tin from dilute solutions

The fluidised bed cell of inert glass beads is an electrolytic reactor which is designed to provide higher ion‐transfer conditions during electrolysis, thus enabling metals to be removed efficiently from dilute solutions. The effectiveness of the method as a means of removing metals from effluent to meet discharge consent levels is studied for the in situ removal of tin from dilute solution (concentration range 0.25–1.00 gdm⁻³). The results show that the combination of high mass transport conditions and a moderately high electrode surface area per unit electrode volume provides a system for continuous removal of metal from dilute solutions. The effects of acid concentration, tin concentration, current density, fluidised bed agitation, electrode spacing, type of electrode and lead impurities on the removal of tin are reported and expressed in terms of the percentage removal of tin (α_Sn), the efficiency of tin deposition (ϕ_Sn), and the energy consumption (W_Sn) for 1 kg of tin deposited. The results show that tin can, under optimised conditions, be removed from dilute solutions to a residual concentration of 0.001 gdm⁻³. © 2001 Society of Chemical Industry     

实际生产中锡污染的综合有效处理

锡槽中的锡由于化学性质活泼,硫化或氧化造成锡污染,导致成型过程中玻璃上下表面出现许多缺陷,严重影响玻璃质量;在实际生产中采取综合处理措施,使锡污染得到有效的控制.     

An electrodeposition metal layers method for magnetic powders and warm-pressing preparation of Nd–Fe–B/Sn-bonded magnets

The method of magnetic stirring in fluid-bed galvanic deposits was used for cladding low-melting-point metallic tins onto the surface of rapid quenching Nd–Fe–B magnetic powders. This form of bonding was also used to make Nd–Fe–B/Sn composite magnets by warm pressing at 300 °C. The tin-plating layers of the Nd–Fe–B magnetic particles were observed by scanning electron microscope (SEM). The magnetic properties of the coated and uncoated powders were examined by vibrating sample magnetometer (VSM), respectively. Furthermore, both the compressive strength and magnetic properties of Sn-coated Nd–Fe–B/Sn-bonded magnets were measured. The results indicate that not only the tin plated and magnetic powders were bonded closely, but also the content of tin-plated layers can be controlled by the electrical current. The (BH)_max and B_r value of magnetic powders decrease with the increasing content of plated tin. An increase in the tin-plated content results in an elevation in magnetic properties of composite magnets by warm-pressing preparation. The composite magnets exhibit excellent integrated magnetic property when the content of Sn was 5.079 wt.%, at (BH)_max = 113.7 kJ m^?3, B_r = 0.821 T, H_cj = 732.6 kA m^?1. The results indicate that the required electrodeposited tin is less than 5 wt.% achieving the same magnetic properties and compressive strength which demands 10 wt.% tin in mechanical mixing method.     

Indium tin oxide nanoparticles as anode for light‐emitting diodes

Thin films of indium tin oxide (ITO) nanoparticles have been investigated as anode materials for polymer light‐emitting diodes. A luminance efficiency (0.13 cd/A), higher than that (0.09 cd/A) obtained in a control devices fabricated on conventional commercial ITO anodes were found. The thin films were made by spin coating of a suspension followed by annealing. The ITO nanoparticle films have a stable sheet resistance of 200 Ω/sq, and an optical transmittance greater than 86% over the range of 400–1000 nm. Their textural property is also reported. These results demonstrate that ITO nanoparticle can form a high efficient reproducible anode material. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3125–3129, 2006