丁二酮肟分光光度法测定硫酸镍生产废水中的镍

本文将丁二酮肟分光光度法应用于硫酸镍生产废水中镍的测定。以过硫酸铵作氧化剂，丁二酮肟为显色剂，在波长的４６５ｎｍ处测定硫酸镍生产废水中的镍。     

丁二酮肟比色法测定高比重合金中镍含量

本采用丁二酮肟比色法测定高比重合金中镍含量的实验条件是：溶液在碱性介质中，在氧化剂存在下，镍与丁二酮肟生成可溶性红色络合物，然后进行比色测定。     

丁二酮肟重量法对泵轴中镍含量的测定

泵轴中镍的测定采用在乙酸铵缓冲溶液中,用酒石酸钾钠作络合剂,以硫代硫酸钠掩蔽铜,在pH值为6.0~6.4时,镍与丁二酮肟生成丁二酮肟镍沉淀,与铁、钴、铜、锰、铬、钼、钨、钒等元素分离,丁二酮肟镍沉淀经140±5℃烘干并称至恒重。     

丁二酮肟光度法在快速测定铜镍合金中镍含量的应用

为了对铜镍合金中的镍进行快速测定,提出了丁二酮肟光度法,利用盐酸和过氧化氢溶解合金样品,加入柠檬酸铵对三价铁离子进行遮蔽,当介质中存在碘时,丁二酮肟可以与镍生成可溶性酒红色络合物,配合分光光度法,能够实现对镍含量的准确测定。     

光度显色试剂的进展(续完)

四、肟类、腙类、1,10-菲啰啉类及其它显色剂 1.肟类试剂自1905年将丁二酮肟用作镍的分析试剂以来至今它仍是重量法和光度法测定镍的一个好试剂。不少肟类均可作镍的显色剂,如苯乙酮肟与Ni(Ⅱ)在PH 7.2～8.0可形成被氯仿萃取的螯合物,ε_(340)=2.24×10~4,灵敏度高于丁二酮肟,曾应用于白铜和不锈钢中镍的测定。α-糠偶酰二肟和甲醛肟也可用于镍的光度测定,但选择性不如丁二酮肟。     

三价铬镀液中镍杂质的分析

以丁二酮肟光度法测定三价铬镀铬溶液中镍杂质的质量浓度。三价铬镀液中的络合剂与镍离子生成比较稳定的络合物,影响丁二酮肟镍的显色反应,用过硫酸铵在加热条件下破坏该络合剂,消除其对测定的影响。以不加显色剂的试样作参比液,在波长470 nm处测定。测定结果的相对平均偏差为1.1%,回收率为97.0%~102%。     

电镀废水中镍的萃取分光光度法测定

测定电镀废水中镍有丁二酮肟-氯仿萃取法、丁二酮肟比色法。这些方法分离效果差,操作繁琐。本文提出用5-Br-PADAP 做显色剂,在 pH 5.5的乙醇介质中用硫代硫酸盐和磷酸盐做掩蔽剂,测定电镀废水中镍。该法稳定性好,操作简便,准确度、精密度、灵敏度都很理想。     

萃取分离-分光光度法测定铜合金中痕量镍

用硝酸溶解试样,在pH 6.0~7.0范围内,用三氯甲烷萃取丁二酮肟镍与铜基体分离。以盐酸反萃取镍。在碱性介质中,氧化剂存在下,镍与丁二酮肟形成络合物,在波长480nm处测定吸光度。0.2~2μg·mL-1范围内符合朗伯-比尔定律,回收率达100.7%,所测镍量范围为0.001%~0.010%。     

锂离子电池高钴正极片中镍的测定

研究了锂离子电池高钴正极片中常量镍的测定。以酒石酸掩蔽铁、钙、镁等杂质,在pH=5.5~6.0时以丁二酮肟沉淀分离镍,用盐酸溶解沉淀,所得溶液蒸发至近干以破坏丁二酮肟;在pH=10的氨-氯化铵缓冲溶液中以过氧化氢氧化返溶得到的镍液中残留的钴,用EDTA滴定镍。方法的回收率为97.56%~101.92%,RSD为0.56%。     

微晶萘固相萃取及固相反射散射分光光度法测定镍的研究

设计了测量镍的新方法,以微晶萘萃取丁二酮肟－镍的配合物,在固相微晶萘上直接用反射散射分光光度法测定信号值ＡＲ。研究表明,此方法灵敏可靠,用于钢样、地质样品中低含量镍的测定,结果全部符合要求。     

关于工业碳酸镍国家行业标准的讨论

在采用国家标准GB/T 26521-2011《工业碳酸镍》对市售的工业碱式碳酸镍测试时发现：镍的含量一直无法达标。通过与行业标准HG/T 2824-2009《工业硫酸镍》对比研究发现：两者只是待测试样不同,测试所需试剂、用量及实验条件等完全相同。但是碳酸镍中的镍含量与硫酸镍中镍含量不同。通过对盐酸和丁二酮肟用量的理论推导和实验验证,对GB/T 26521-2011提出了修订完善的方法和建议。     

Selective nickel recovery from iron-rich solutions

This study aims to demonstrate the selective removal of iron from acidic leach solutions using an effective purification method and to convert nickel into a usable form. The method of removing iron by using CaCO₃, which is a better precipitation reagent, was optimized using Response Surface Methodology. A further evaluation was carried out on the complexation of Ni(II) ions with dimethylglyoxime to obtain a high-yield nickel-dimethylglyoxime complex from nickel remaining in the solution after iron precipitation. Taking into account nickel losses to remove iron, pH should be within the range of 3–4, and low temperatures around 25°C should be used.     

Spectrophotometric determination of nickel in steels

New, simple and sensitive spectrophotometric methods for the determination of nickel with hematoxylin in the presence and absence of a cationic surfactant are described. The sensitivity of the color reaction of nickel and hematoxylin is greatly increased by the sensitizing action of cetyltrimethylammonium bromide (CTAB). The optimum pH range for the formation of nickel-hematoxylin and nickel-hematoxylin-CTAB systems is 7.8–8.3 and 7.4–8.1, respectively. The molar absorptivities are 4.1 × 10⁴ and 8.3 × 10⁴ mol^?1 cm^?1 at 595 and 608 nm, respectively. The corresponding values of Sandell's sensitivity index are 0.0014 and 0.0007 μg cm^?2 of nickel. The methods adhere to Beer's law up to 0.52 and 0.60 ppm nickel, respectively. The mole ratio of nickel-hematoxylin in both complexes is 1:2. Preliminary separation of nickel by extraction as dimethylglyoxime chelate into chloroform makes it possible to determine nickel in steel samples.     

载镍碳纳米管的载镍量分析

采用灼烧法预处理、丁二酮肟重量分析法来测定载镍碳纳米管的载镍量,获得稳定而准确的分析结果。结果表明,制备载镍碳纳米管催化剂时所加入的镍并不全部吸附在碳纳米管上;载镍效率随着碳纳米管载镍量的增加而降低。     

分光光度法测定不锈钢中镍含量方法的改进

对以碘为氧化剂、丁二酮肟为显色剂,采用分光光度法测定不锈钢中镍的条件进行了探讨和改进。     

Reclamation of nickel from spent nickel catalyst

Spent nickel catalyst containing an average 9.6% nickel was obtained locally from an oil hydrogenation industry. It was digested with 1–3N HCl, HNO₃, H₂SO₄ and mixtures thereof in one to three stages of durations ranging from one to three hr at 100°C using spent nickel catalyst to acid proportions of 1:3 to 1:8 (w/v). Nickel recoveries of over 94% were obtained when one part of spent catalyst was digested for three hr with six or more parts of 3N mixture of HCl and HNO₃ (3:1, v/v). Acid extracts of spent nickel catalyst obtained using HCl, H₂SO₄ and mixtures thereof were treated with NaOCl to convert their content of iron in the ferric form. The iron from the nickel extract was precipitated out in the form of ferric hydroxide at pH 6.0. Nickel from the iron-freed acid extracts was recovered at pH 8.5±0.5 as nickel hydroxide. Nickel formate was prepared by refluxing nickel hydroxide with 10% formic acid in about 6% excess to stoichiometric requirements for 30 min. The dried nickel formate was reduced in peanut oil at 230°C to 270°C for 0.25 to 2.75 hr. The reduction at 260°C on kieselguhr support, employing nickel formate:oil:support in ratio of 50:43:7, for two hr provided catalyst of maximum activity. The hydrogenation activity of the reclaimed catalyst, assessed by standard AOCS procedure, was greater than that of the parent catalyst. Presented at the AOCS Meeting in New Orleans, LA, in May 1987.     

电子工业用镍包铜粉的工艺及性能研究

采用不同粒度的片状铜粉,以次磷酸钠作为还原剂,通过化学镀镍制备出性价比较高的、具有较好电磁屏蔽性能的镍包铜粉。讨论了铜粉粒径及镍含量对镍包铜性能的影响,结果表明,粒径大的铜粉较易进行化学镀镍,而镍包铜粉电阻随铜粉粒径减小而增大;随镍含量的减少,镍包铜粉的颜色变浅,电阻减小。SEM照片显示,镍包铜粉形貌较好,片状化程度较好。镍含量为30%时镍包铜粉磷含量较低,实际成分含量与理论相符,松装密度及导电性较好,是理想的电磁屏蔽材料。     

Supported nickel catalyst from hydroxycarbonate of nickel and aluminium

The hydroxycarbonate of nickel and aluminium (Ni/ Al = 3) with a hydrotalcite-like structure is an outstanding precursor of the active component of supported nickel catalysts. Good mechanical strength and suitable nickel content of these catalysts, which are necessary for practical applications, can be achieved by mechanical mixing of this compound with an additional support. The catalyst prepared from a mixture of 56.5 wt-% of nickel-aluminium hydroxycarbonate and 43.5 wt-% of γ-alumina was proven to have a stable catalytic activity in the methanation reaction at 2 MPa and 800 K.