共查询到20条相似文献,搜索用时 187 毫秒
1.
在Ni-Fe-P非晶态合金电镀工艺研究中,采用循环伏安法研究了某些有机酸和亚磷酸对Ni2+、Fe2+在铂电极上的电化学行为的影响。结果认为,甘氨酸、抗坏血酸和丁二酸等均能不同程度地增大Ni2+、Fe2+的阴极极化,亚磷酸能促进Ni2+的还原析出,但阻止Fe的成核和生长过程。 相似文献
2.
从褐煤抽提得到的腐植酸与阳离子相互作用的研究表明,Mg^2^+,Ca^2^+,Zn^2^+,Cu^2^+,Al^3^+和Fe^3^+与腐植酸形成络合物。对这些阳离,Fe^3^+具有最大的形成络合物倾向。吸留能力按这样的顺序,Fe^3^+>Al^3^+>Cu^2^+>Zn^2^+>Ni^2^+>Co^2^+>Mg^2^+,值得注意的是表现优先吸收的阳离子是以酸度增加为基础的。最前面的阳离子有最大的酸 相似文献
3.
采用循环伏安法研究了Ni^2+、Fe^2+、H2PO2^-、H2PO3-在悬汞电极上的电化学行为以及H2PO2^-、H2PO3^-在KCL支持电解质中的不原机理,对电沉积Ni-Fe-P非晶态合金中磷的沉积机理有进一步的认识。 相似文献
4.
氯化物溶液中电镀锌镍合金 总被引:2,自引:0,他引:2
提出氯化物镀液中锌镍合金电镀配方,镀液中Ni^2+浓度不同,镀层镍含量不同。在45-55℃-55℃,Dk为5-25mA/cm^2,镀液Ni^2+/Zn^2+/Zn^2+为6%-37%时,能获得满意的镀层。结果表明,锌镍合金镀层性能优于纯锌镀层。 相似文献
5.
EDTA滴定法测定Zn^2+与Fe^2+混合物中的Zn^2+ 总被引:2,自引:0,他引:2
在质量检验工作实践中,发现有的硫酸锌样品呈浅蓝色,定性实验证明,混有硫酸亚铁。原行业标准(HG3277-1986)中测定锌含量所用的屏蔽剂(NH4F和KI)不能消除Fe^2+的影响,致使Fe^2+被以Zn^2+的表示方式检测出来,测定的锌含量实际上是Zn^2+与Fe^2+之和,本研究提出了先用H2O氧化Fe^2+变成Fe^3+,然后再测定锌含量,结果更为准确、重现性好。 相似文献
6.
电镀Zn—Ni合金自动控制系统的研究 总被引:2,自引:0,他引:2
针对Zn-Ni合金电镀工艺和电镀生产的实际情况,介绍一种电镀Zn-Si合金自动控制系统,并对Zn^2+、Ni^2+的自动检测方法和具体实现,进行了详细介绍。 相似文献
7.
以P507有机膦酸酯作萃取剂,利用溶剂萃取法,在pH=3、相比为1:2的条件下,经过四级萃取,可将含Ni^2+溶液(Ni^2+含量5.61%)中的杂质Zn^2+含量从3296ppm降至68ppm。该法可应用废转化触媒回收镍中杂质锌的分离。 相似文献
8.
利用巯基羊毛对重金属离子Zn^2+,Cu^2+Pb^2+的水溶液进行了吸附研究。探讨了巯基羊毛对这些金属离子的吸附性能,结果表明,最佳吸附酸度为Cu^2+:pH=4.0~7.0,Pb^2+:pH=4.2~6.0,Zn^2+:pH=4.5~7.3饱和吸附量为Cu^2+:1.19mg/g,Pb^2+:2.82mg/g,Zn^2+:1.22mg/g并对该三种金属离子的分离,富集,回收和巯基羊毛的再生条件 相似文献
9.
用离子交换树脂分离硫化胶中的Ca^2+,Mg^2+Zn^2+等共存离子,以便消除组液时的互相干扰,用常规法依次测定,不加入掩蔽剂,避免了常规法在测定它们时使用的剧毒化学试剂-氰化钾作为掩蔽剂而对操作者及环境所带来的危害。 相似文献
10.
合成了一种硫脲-尿素-甲醛树脂1和两种冠醚聚合物II和Ⅲ,探讨了它们对Hg^2+,Zn^2+,Cd^2+等金属离子的吸附分离性能,且冠醚聚合物可反复使用,可望用于工业废水中含汞废水的处理。 相似文献
11.
The effect of the presence of commercial organic extractants LIX 84I, Cyanex 272, D2EHPA, Versatic 10 and TBP with or without Mg2+ on various electrodeposition parameters for nickel deposition on stainless steel cathode from aqueous sulphate solutions was investigated. The parameters included cathodic current efficiency, deposit morphology, crystal orientation and cathodic polarization. There was no significant variation in the current efficiency in the presence of these additives, but changes were observed in the deposit morphologies and crystal orientations even though all the deposits were bright, smooth and coherent. Changes were also observed in the cathodic polarization behaviour during nickel electrocrystallization in the presence of these additives. The effect of the additives on the electrokinetic parameter, exchange current density (i
0) has also been investigated. 相似文献
12.
M. M. Kamel 《Journal of Applied Electrochemistry》2007,37(4):483-489
Thin films of cobalt–nickel alloys were galvanostatically deposited onto steel substrates from gluconate baths. Cathodic polarization
curves were determined for the parent metals and Co–Ni alloy. The effects of bath composition, current density and temperature
on cathodic current efficiency (CCE) and alloy composition were studied. The deposition of Co–Ni alloy is of anomalous type,
in which the less noble metal (Co) is preferentially deposited. The CCE of codeposition is high and increases with increase
in temperature and current density, but it decreases as the [Co2+]/[Ni2+] ratio in the bath increases. The percentage of Co in the deposit increases with increasing cathodic current density, temperature
and increasing Co2+ ion concentration. The structure and surface morphology of the deposit were studied by XRD, ALSV and SEM. The results showed
that the alloys consisted of a single solid solution phase with a hexagonal close packed structure. 相似文献
13.
4-(6-‘-溴苯噻唑偶氮)-3-羟基苯甲酸[4-(6‘-bromobenzothiazolylazo)-3-hydroxybenzoic acid, 即Br-BTAHA]是Cu^2 ,Co^2 ,Mi^2 的很好的显色剂和酸碱指示剂,用Br-BTAHA作指示剂,以EDTA分别滴定Cu^2 ,Co^2 ,Ni^2 及Co^2 ,Ni^2 ,Cd^2 ,Pb^2 ,Zn^2 ,终点由蓝色突变为绿(或橙色)及黄绿(或橙红)色,终点清晰敏锐。根据Ringbom误差公式计算,Br-BTAHA完全具备配位滴定指示剂的各项必备条件,是一种选择性和准确度均好的指示剂。 相似文献
14.
La掺杂Ni0.5Zn0.5Fe2O4铁氧体的制备与微波吸收性能 总被引:2,自引:1,他引:1
采用高分子凝胶法制备了Ni0.5Zn0.5LaxFe2-xO4 (x=0, 0.05, 0.1)铁氧体,采用XRD, TEM和HP8510网络分析仪对其结构、形貌、电磁和微波吸收性能进行了研究. 结果表明,当煅烧温度为600℃时,立方晶系尖晶石结构的Ni0.5Zn0.5La0.05Fe1.95O4相初步形成,La在尖晶石结构中固溶量有限. 与Ni0.5Zn0.5Fe2O4铁氧体相比,掺杂La的Ni-Zn铁氧体的tandm值降低,tande值升高. 与Ni0.5Zn0.5Fe2O4铁氧体相比,x=0.1样品的吸波性能降低,而x=0.05样品的吸波性能提高,其电磁波反射率小于-10 dB的频宽可达2.7 GHz,最小反射率为-15.6 dB. 相似文献
15.
B.C. Tripathy S.C. Das P. Singh G.T. Hefter D.M. Muir 《Journal of Applied Electrochemistry》2001,31(5):573-577
The effects of metal ions such as Mg2+, Li+, Na+ and K+ on the cathodic current efficiency, deposit morphology, crystallographic orientation and polarization behaviour during nickel deposition on stainless steel from aqueous sulfate solutions containing boric acid were investigated. There was virtually no change in current efficiency in presence of these metal ions, but changes were observed in the deposit morphologies and crystal orientations even though all the deposits looked bright, smooth and coherent. Changes were also observed in the polarization behaviour during nickel electrocrystallization in presence and absence of boric acid. An attempt has been made to correlate the effect of these metal ions on various parameters studied. 相似文献
16.
Experimental results for the electrodeposition of Ni-Zn alloys from chloride solutions, with addition of H3BO3 and without other additives, in a laboratory cell with a perforated nickel sheet cathode and with recirculating electrolyte are presented. The dependence of the zinc content in the alloy on the following operating conditions was investigated: cathodic current density, 1.0–20.0 A dm–2; temperature, 35–65°C; pH 1.5–5.5; total molarity,M
tot=M
Ni
2+
+M
Zn
2+
=1.1–2.8 M; and, molar ratio,P=M
Ni
2+
/M
Zn
2+
=1.0–15. Depending on the operating conditions the Zn content in the alloy varied over the range 22–88 mol%. In separate experiments galvanostatic polarization curves were measured in the direction of increasing and then decreasing cathodic current density in the range 0.1–20.0 A dm–2 with all other operating conditions as used for electroplating experiments. In all cases significant hysteresis effects were observed. It was found that the current efficiency for the electrodeposition of Ni-Zn alloys from chloride solutions as a function of the zinc content in the alloy showed a sharp minimum of about 55% atX
Zn=55 mol % irrespective of other operating conditions. 相似文献
17.
18.
依据实验结果和文献数据讨论了有机磷酸类萃取剂萃取钴及镍的动力学行为.结果表明,有机磷酸酸性强,溶入水相的速度快,则萃取速度亦快,钴和镍的萃取速度差异由溶剂交换速度决定. 相似文献
19.
Shi-Ping Gou 《Electrochimica acta》2008,53(5):2538-2544
The electrodeposition of nickel and nickel-zinc alloys was investigated at polycrystalline tungsten electrode in the zinc chloride-1-ethyl-3-methylimidazolium chloride molten salt. Although nickel(II) chloride dissolved easily into the pure chloride-rich 1-ethyl-3-methylimidazolium chloride ionic melt, metallic nickel could not be obtained by electrochemical reduction of this solution. The addition of zinc chloride to this solution shifted the reduction of nickel(II) to more positive potential making the electrodeposition of nickel possible. The electrodeposition of nickel, however, requires an overpotential driven nucleation process. Dense and compact nickel deposits with good adherence could be prepared by controlling the deposition potential. X-ray powder diffraction measurements indicated the presence of crystalline nickel deposits. Non-anomalous electrodeposition of nickel-zinc alloys was achieved through the underpotential deposition of zinc on the deposited nickel at a potential more negative than that of the deposition of nickel. X-ray powder diffraction and energy-dispersive spectrometry measurements of the electrodeposits indicated that the composition and the phase types of the nickel-zinc alloys are dependent on the deposition potential. For the Ni-Zn alloy deposits prepared by underpotential deposition of Zn on Ni, the Zn content in the Ni-Zn was always less than 50 atom%. 相似文献
20.
YOSHIHIRO HAYASHI TOSHIO KIMURA TAKASHI YAMAGUCHI 《Journal of the American Ceramic Society》1986,69(4):322-325
Nickel-zinc ferrite powder was prepared from the constituent oxides in the presence of molten Li2 SO4 -Na2 SO4 . The effect of ZnO on the reactivity of NiO was studied. The process of Ni-Zn ferrite formation was followed by X-ray diffraction and thermomagnetic analyses. Particle size and shape of the product were determined by scanning electron microscopy. In the presence of molten salt, ZnO enhances the reactivity of NiO, and Ni-Zn-ferrite formation is completed at lower temperature than Ni ferrite formation. In the reaction for the formation of Ni-Zn ferrite, Zn ferrite forms before NiO is incorporated into the ferrite phase. The reaction between the initially formed Zn ferrite and NiO leads to a rate of Ni-Zn ferrite formation higher than that of Ni ferrite formation from NiO and Fe2 O3 . 相似文献