银阳极泥硝酸浸出液中铂和钯的还原富集

银阳极泥在硝酸浸出时,大部分铂和钯会进入溶液,最终返回熔炼系统,铂钯直收率因此偏低。研究了亚硫酸氢钠还原沉淀硝酸浸出脱银液中铂和钯的工艺条件。结果表明,还原剂用量、硝酸浓度、反应温度和时间均对铂和钯沉淀率有影响。在优化条件下,铂和钯的沉淀率分别可达到99.5%和99.7%,所得精矿中铂和钯含量分别为1.70%和13.59%。     

从钯银合金废料中回收钯的实验研究

以钯银合金废料为原料,采用硝酸溶解-盐酸沉银-二氯二氨络亚钯法提纯-水合肼还原工艺回收钯。结果表明,当浓盐酸用量为2 m L/200 m L混合酸液,反应时间1 h时,银沉淀率为99.98%;当氨络合和盐酸酸化沉淀过程溶液最佳p H分别为8和1.5,并经温水洗涤3次,二氯二氨络亚钯纯度达到99.99%以上;该工艺钯回收率大于90%,并制得纯度大于99.99%的海绵钯,其平均粒径不大于0.5μm。     

从生产乙醛废催化剂渣中回收钯和铜

以盐酸为浸出剂,H_2O_2为氧化剂,采用二段逆流浸出法先将Pd和Cu从废催化剂泥渣中浸出,然后采用乙基黄原酸钠为沉淀剂,进行钯的富集,达到钯和铜的分离。还比较了不同的盐酸浓度对钯的浸出效果以及不同pH值及乙基黄药的加入量对钯沉淀的影响。     

分子识别技术分离提纯钯的工艺实验

采用分子识别材料SuperLig^ò2从含铂钯的溶液中选择性分离钯,钯吸附率大于99%,吸附、洗脱过程钯的直收率为95.87%,总收率为98.04%;得到的洗脱液氧化处理后生成钯沉淀,再经水合肼还原即可得到纯度为99.99%的钯粉。与传统的沉淀分离工艺相比,分子识别技术的生产流程短、铂不容易分散、操作方便、三废量少。     

铂钯精矿中氯化银的浸出预处理研究

铜阳极泥分铜液所得铂钯精矿中的银主要以氯化银(AgCl)形态存在，可用氨水或亚硫酸钠作为浸出剂去除银。绘制了Ag⁺与NH3、SO2- 3配体组分图，结合电位-pH图分析表明，氨浸的pH值范围为7.7~13.5，亚硫酸钠浸出宜在中性或碱性条件下进行。优化条件实验结果表明，银的氨浸浸出率为95.3%，碲浸出率为14.9%，有微量铂、钯浸出；以亚硫酸钠为浸出剂，银的浸出率为97.3%，碲浸出率为11.5%，金、铂和钯均不被浸出。亚硫酸钠更适于作为铂钯精矿预处理除银的浸出剂。     

从铂钯精矿中回收铂、钯和金

采用焙烧-预浸出-氯化浸出-萃取-精制工艺处理铜冶炼阳极泥产出铂钯精矿回收铂、钯、金。结果表明,氯化液采用亚硫酸钠控制电位还原,金回收率99%;金还原后液采用二异戊基硫醚萃取钯,氨水反萃,钯回收率90%;萃钯余液采用三烷基胺萃取铂,氢氧化钠反萃,铂回收率90%。铂、钯符合国标99.99%产品要求,粗金粉品位97.09%。     

从环氧乙烷用失效催化剂中回收银

采用流态化浸出技术研究了从环氧乙烷用失效银催化剂中银的工艺。考察了流化状态、硝酸用量、反应时间等参数对银浸出效果的影响,得到了最佳工艺条件。采用自制流化态溶解装置,使废催化剂处于流动翻滚状态,硝酸用量为理论用量的1.2倍,反应时间不低于1 h,银的浸出率可达到99.88%。浸出液氯化沉淀后采用传统方法精炼提纯,得到99.95%纯度的银。     

从微电子元件废料中再生提纯钯银

本文论述了从微电子元件废料中再生提纯钯，银的方法，研究了各种金属在溶液中的化学特性的差异，采用硝酸溶样，所化钠沉淀分离银；氨络合－盐酸酸化除铜，镍，铁等贱金属而制取高纯度钯，银。     

银钯合金超细粉末制备工艺研究

研究了以水合联氨作还原剂,从硝酸银和硝酸钯溶液中直接还原出Ａｇ－Ｐｄ合金超细粉末,通过化学势和学分析可知,水合联氨与银,钯反应的标准电极电位差值很大,远远高于银与钯标准电极电位的差值,可以实现银和钯同步还原。在溶液中银和钯离子浓度为７０ｇ／Ｌ．Ａｇ：Ｐｄ＝７：３,水合联氨的加入量为理论量６倍,还原温度为５０℃－６０℃条件下,可获得平均粒径为０．６μｍ的Ａｇ－Ｐｄ合金粉末。     

活化-溶解法规模化生产硝酸钯的工艺研究

通过对稀王水控量溶解钯的条件、活性钯粉的还原条件、硝酸溶解钯的条件研究,解决了部分钯粉不能完全溶解的困难,建立了活化-溶解法规模化生产硝酸钯的工艺条件。对活化前后钯粉的粒度、比表面积和表面形貌分析的结果表明,活化后钯粉颗粒变小,表面积增大,扫描电镜显示,活化后钯粉粒径变小,呈海绵状,钯的溶解活性提高,有利于钯粉的完全溶解。     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

Rheology Feature of Simple Metal Melt

The rheology feature of Sb, Bi melt and alloys was studied using coaxial cylinder high-temperature viscometer. The results showed that the curve of torsion-rotational speed for Sb melt presents a linear relation in all measured temperature ranges, whereas for the Bi melt, the curve presents obvious non-Newtonian feature within the low temperature range and at relative high shear stress. The rheology feature of Sb80Bi20 and Sb20Bi80 alloy melts was well correlated with that of Sb and Bi, respectively. It is considered that the rheology behavior of Sb melt plays a crucial role in Sb80Bi20 alloy and that of Bi melt plays a crucial role in Sb20Bi80 alloy.     

Microstructures and Mechanical Properties of a Newly Developed Austenitic Heat Resistant Steel

The effect of heat treatment on the microstructures and mechanical properties of a newly developed austenitic heat resistant steel(named as T8 alloy) for ultra-supercritical applications have been studied. Results show that the main phases in the alloy after solution treatment are γ and primary MX. Subsequent aging treatment causes the precipitation of M_(23)C_6 carbides along the grain boundaries and a small number of nanoscale MX inside the grains. In addition, with increasing the aging temperature and time, the morphology of M_(23)C_6 carbides changes from semi-continuous chain to continuous network.Compared with a commercial HR3C alloy, T8 alloy has comparable tensile strength, but higher stress rupture strength. The dominant cracking mechanism of the alloy during tensile test at room temperature is transgranular, while at high temperature, intergranular cracking becomes the main cracking mode, which may be caused by the precipitation of continuous M_(23)C_6 carbides along the grain boundaries. Typical intergranular cracking is the dominant cracking mode of the alloy at all stress rupture tests.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

The 15th Global Foundry Sourcing Conference 2014held in Qingdao China

Organized by Suppliers China Co., Ltd and co-organized by the National Technical Committee 54 on Foundry of Standardization Administration of China, the 15th Global Foundry Sourcing Conference 2014 （hereinafter referred to as FSC 2014） was successfully held on Sep. 23rd in Grand Regency Hotel, Qingdao. More than 500 delegates from home and abroad attended this conference, including over 130 purchasers from 20 countries and 380 domestic and foreign suppliers.     

Secondary Recrystallization Behaviors of Grain-Oriented 6.5 wt% Silicon Steel Sheets Produced by Rolling and Nitriding Processes

By rolling and nitriding processes, 0.23- to 0.3-mm-thick grain-oriented 6.5 wt% silicon steel sheets were produced. The core losses of grain-oriented 6.5 wt% silicon steel at frequencies ranging from 400 Hz to 20 k Hz were lower than that of the grain-oriented 3 wt% silicon steel with the same thickness by 16.6–35.8%. The secondary recrystallization behavior was investigated by scanning electron microscopy, energy-dispersive spectroscopy, and electron backscattered diffraction. The results show that the secondary recrystallization in high-silicon steel sheets develops more completely as the nitrogen content increases after nitriding, secondary recrystallized grain sizes become larger, and the sharpness of Goss texture increases. Because more {110}116 grains in the subsurface and the central layer of the sheets have a lot of 20°–45° high-energy boundaries in addition to Goss grains, {110}116 can be the main component through selective growth during secondary recrystallization when the inhibitor quantity is not enough and inhibitor intensity is weaker. The increases in nitrogen content can increase the inhibitor intensity and hinder abnormal growth of a mount of {110}116 grains and therefore enhance the sharpness of Goss texture.     

Laser Cladded TiCN Coatings on the Surface of Titanium

Laser cladded coatings of TiCN were produced on the surface of titanium. To obtain the optimal techniques, several conditions were tested by varying the laser scanning rate. The choice of shielding gas was also studied. The cladded coatings were then evaluated from the surface mechanics point of view based on their microhardness. The microstructure of some interesting samples was investigated by optical micrographs (OM). The results showed that under the condition of fixed pulse frequency and pulse width, the laser scanning rate and the shielding gas are the main factors influencing the components of coatings. TiCN coatings were decompounded and oxidized during the cladding process in the condition of no shielding gas of N2. X-ray diffraction results indicated that the composite coatings composed of TiCN, TiC, Ti2N, and TiO2 were produced using appropriate techniques. The results indicated that the best condition in terms of the surface microhardness is obtained when the scanning rate is 1.5mm / s, the pulse frequency is 15Hz, the pulse width is 3.0ms, and N2 is chosen as the shielding gas. The microhardness of the composite coatings is about 1331kg · mm - 2, which is about 4 times that of the substrate. The optical micrographs indicated that the cladding zone is made up of TiCN, TiO2, and some interdendritic Ti, but the diffusion zone mainly consists of the dendrites phase, and the cladded depth is about 80?滋m, which is more than 2 times that of the laser nitrided sample. There were no microcracks or air bubbles in the cladded sample, which was cladded using the above optimal techniques.     

Effect of Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

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正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis