EDTA络合滴定法测定锌铝合金中的锌

采用强碱溶样,用氟化铵、酒石酸作掩蔽剂以解决测定合金中锌含量时Al~(3+)、Fe~(3+)等离子对测定的干扰,并考察了酸碱溶样、掩蔽剂的用量、pH对测定结果的影响。结果表明,在pH=5.5的HAc-NaAc缓冲溶液介质中,分别加入质量分数为10%的12 mL氟化铵、质量分数50%的14 mL酒石酸时,可有效掩蔽干扰离子。该方法简单、方便,可满足锌铝合金中锌的测定。     

金属气门嘴铜锌含量的快速测定方法

在生产企业中要求快速、准确地测定内胎金属气门嘴中铜锌含量，以满足生产需要。本方法是在同一试液中用碘量法测定其中的铜含量之后，再加氰化钾将铜、锌离子掩蔽，又加甲苯把锌离子解除掩蔽，用络合滴定法测定其中的锌含量。这种连续测定同一试液中的铜、锌含量的方法，可提高工效３倍。     

分光光度法测定卤水和食盐中微量锌

提出了以硫脲、抗坏血酸作掩蔽剂,用二甲酚橙分光光度法测定卤水和食盐中微量锌的方法。     

分光光度法测定卤水和食盐中微量锌

提出了以硫脲、抗坏血酸作掩蔽剂、用二甲酚橙分光光度法测定卤水和食盐中微量锌的方法。     

EDTA容量法测定氧化锌锡粉末材料中的锌

采用 EDTA容量法测定氧化锌锡粉末中的锌含量.以酒石酸为掩蔽剂掩蔽锡,用氨水调节pH值并加入六亚甲基四胺-HCl缓冲溶液,将pH值控制在 5.10,以二甲酚橙为指示剂直接滴定锌.锌的回收率在97.6%～100.5%之间,标准偏差和相对标准偏差都符合分析要求.     

碱性锌酸盐镀锌液中锌的测定

碱性锌酸盐镀锌液中锌的测定,过去大多采用在pH=l0的氨性缓冲溶液中,用氰化物将主要元素锌及铜、铁和铅等杂质络合掩蔽,然后加入甲醛解蔽,以EDTA标准溶液滴定镀液中的锌,但是由于这种方法使用了剧毒的氰化物.在分析过程中,又危害分析人员的健康.国内外广大分析化验人员对碱性锌酸盐镀锌液中锌的分析测定,作了许多有益的探讨,并寻求了许多种新的测定方法.但是,某些方法虽然分析测定准确,测定的步骤却比     

容量法测定微量元素预混合饲料中锌、铜含量

探讨了用容量法测定微量元素预混合饲料中锌、铜含量的分析条件;样品用盐酸和硝酸处理后,用EDTA滴定法测定锌、铜合量,再用硫脲掩蔽铜,用EDTA滴定法测定锌含量,总量减去锌含量即可得到铜含量。     

锌-镍合金镀液中锌、镍、氢氧化钠的分析方法

锌的测定方法,用抗坏血酸还原三价铁离子,再加入氰化物掩蔽Fe^2＋、Zn^2＋、Ni^2＋、Cu^2＋等,而锌氰配位化合物不稳定,加甲醛即被解蔽,以铬黑T为指示剂用EDTA滴定。NaOH的测定,用中和滴定法完成。镍是用比色分析法,在碱性溶液中,当有氧化剂存在时,利用镍与丁二酮肟不产生沉淀而形成酒红色化合物的特性,以吸光光度法测定镍的含量。     

酸性氯化物锌-钴合金镀液中锌钴的测定

首先利用酸性镀液中钴本身的颜色，以水作参比，在波长为520nm处，直接用分光光度法测定Co^2 含量，然后，在pH=5.5的条件下，以二甲酚橙作指示剂，用EDTA滴定锌钴求出锌钴合量，再用锌钴合量减去镀液中的钴含量从中得到锌的含量。方法简单快速，测量结果准确，能满足实际生产要求。     

氰化镀铜溶液中锌杂质的分析

介绍了用三乙醇胺作掩蔽剂取代氰化钾来测定氰化镀铜溶液中锌杂质的方法。三乙醇胺与Cu+离子生成稳定的配合物,在左旋抗坏血酸存在的条件下,Cu+离子不能被氧化成Cu2+离子。测定时加甲醛破坏游离氰化钠,以铬黑T作指示剂,在pH=10的条件下用EDTA滴定锌。实验表明,测定结果的相对平均偏差为1.4%。     

利用锌渣生产溴化锌

研究了以锌渣为原料制备溴化锌工艺中原料配比、ｐＨ值、反应温度等工艺条件。     

Optical Properties of Zinc Aluminate, Zinc Gallate, and Zinc Aluminogallate Spinels

The optical spectra of zinc aluminate (ZnAl₂O₄), zinc gallate (ZnGa₂O₄), and zinc aluminogallate (ZnAlGaO₄) spinel powders were studied at wavelengths in the range of 250-900 nm using reflectance spectroscopy. The ZnAl₂O₄ and ZnGa₂O₄ powders were synthesized by using conventional ceramic processing techniques and had systematic variations in the molar ratio of ZnO to M₂O₃ (M = Al or Ga). The cubic spinel crystal structure of each composition was confirmed via powder X-ray diffractometry. The ZnAl₂O₄ powders showed optical properties in the ultraviolet wavelength region and had combined characteristics that were similar to that of ZnO (wurtzite structure) and Al₂O₃ (corundum structure), which result from the similar local environments of the zinc and aluminum cations within the cubic spinel crystal structure. A mechanically induced optical absorption (optomechanical effect) in the ultraviolet wavelength region was also observed in ZnAl₂O₄. The ZnGa₂O₄ powder followed a similar behavior, with the exception that the optomechanical effect did not occur in the gallate. The ZnAlGaO₄ showed optical spectra that were intermediate to that of the endpoint compositions.     

Zinc Vanadates in Vanadium Oxide-Doped Zinc Oxide Varistors

Convergent-beam electron diffraction has been used to determine the space groups of β- and γ-Zn₃(VO₄)₂ particles in vanadium oxide-doped zinc oxide varistors. The crystal structure of β-Zn₃(VO₄)₂ has been determined to be monoclinic with space group P 2₁ and lattice parameters of a = 9.80 Å, b = 8.34 Å, c = 10.27 Å, and β= 115.8°, whereas that of γ-Zn₃(VO₄)₂ is monoclinic with space group Cm and a = 10.40 Å, b = 8.59 Å, c = 9.44 Å, and β= 98.8°. Energy-dispersive X-ray microanalysis of these two phases shows significant deviations from their expected stoichiometry. It is apparent that the β-phase is, in fact, the metastable Zn₄V₂O₉ phase, whereas the γ-phase either is a new oxide that consists of zinc, vanadium, and manganese or, more likely, is a zinc vanadate phase with a Zn:V atomic ratio of 1:1 that has the ability to go into solid solution with manganese.     

锌粉含量的测定

锌粉是一种带蓝灰色或浅灰色粉末,可用于镀锌、铸件、锌锰干电池、肥料、颜料等工业.通过实验利用两种方法对锌粉含量法进行测定,并对两种方法进行对比分析,进而选择简便快捷的方法.     

差示扫描量热法测定锌粉和富锌底漆中的锌含量

采用差示扫描量热法（DSC）测定了锌粉与富锌底漆中的金属锌含量。分析了测试过程中可能出现测定误差的原因,提出了提高分析精度的方法。     

Quantitative Analysis of Zinc Vaporization from Manganese Zinc Ferrites

Zinc vaporization of Mn-Zn ferrites was quantitatively characterized in terms of oxygen partial pressure P _O2, temperature, grain size and sample geometry. The amount of zinc loss was measured as a function of time at various temperatures by a thermogravimetric method. The weight loss due to irreversible zinc vaporization showed a linear behavior with time and increased exponentially with temperature. The observed weight loss due to zinc evaporation at 1100°C was small, whereas a significant weight change was detected at 1200°C. The weight loss was even greater in a reducing atmosphere ( P _O2= 5 × 10⁻⁵). Below 1300°C, the diffusion of elemental zinc was sufficiently fast to compensate the zinc loss at the interface region, resulting in a linear dependence on time. At temperatures ≥1400°C, the weight change no longer followed the linear dependence and showed a rather parabolic behavior with a concave upward slope. The core shape and the gas flow around ferrite cores were important factors that affected the rate of zinc vaporization, but not the grain size.     

利用锌浮渣制备四脚状氧化锌晶须

首次采用锌浮渣为原料,利用平衡气量控制法制备了四脚状氧化锌晶须(T-ZnOw),探讨了原料、反应温度和反应器密封程度等因素对产物ZnO结晶结构和形貌的影响,并采用XRD, FE-SEM、表面能谱(EDS)对其结构和形貌进行了测试表征. 结果表明,具有完整结构的四脚状晶须产品仅由Zn和O组成,O原子数少于化学计量比,且核心部位O含量最低;制备具有规整结构的四脚状氧化锌晶须的最佳反应温度为900℃;以不同锌品位的锌浮渣为原料制备的产品均为具有六方纤锌矿结构的结晶完整的氧化锌,但产品形貌和四脚状晶须的产率受原料中氧化锌含量和Sb含量的影响. 研究表明,制备四脚状氧化锌晶须是锌二次资源回收利用的一条高附加值的途径.     

锌粉、锌片与重防腐

简介了高锌防腐涂料的分类和性能指标,指出锌片颜料完全可以替代锌粉颜料用于重防腐领域,从而节省锌资源.     

锌灰制备活性氧化锌工艺

以炼锌厂废锌灰为原料,经硫酸浸取,考察了不同工艺条件对锌的浸出率的影响.实验结果表明:锌灰在50℃下浸取,pH值为1.5时,可使锌灰中锌的溶出率达92.9%.碱式碳酸锌最佳水解温度为40℃,水解时间为2h,pH值为7.5时,溶液中锌含量为10g/L,得到96%以上的水解率.     

低纯度氧化锌制备磷酸锌研究

研究了用低纯度氧化锌(96%)通过复合溶剂净化,同时将氧化锌转化为液相改变传统的固-液相反应为液-液反应制备磷酸锌的新工艺,考察了净化和液-液反应的有关的工艺条件,制备得到高纯度磷酸锌。