Determination of zinc in blast furnace flue dusts

Two methods for the determination of zinc in blast-furnace flue dusts are described. One involves a solvent extraction step using methyl isobutyl ketone to separate the zinc from the bulk of the interfering elements, followed by a complexometric titration of the zinc with EDTA, using Eriochrome Black T as indicator. The other employs differential pulse polarography with a hydrochloric acid + pyridine supporting electrolyte. In this method, the interference of iron is prevented by reducing it with hydroxylamine hydrochloride; aluminium is complexed with potassium fluoride. Other elements, with the exception of cobalt, do not interfere. Excellent agreement between the two methods is obtained in the range 0.01–0.6% zinc.     

The polarographic determination of indium in zinc-base alloys : The determination of indium in zinc and in zinc alloys of low aluminium content

Studies of the application of an 8-hydroxyquinoline extraction and of a zinc oxide “collection” procedure for the separation of trace amounts of indium from zinc alloys are described and discussed. A combination of radio-chemical and polarographic determination were employed for this work. A polarographic method for the determination of indium in zinc and in zinc alloys of low aluminium content is presented     

Spectrophotometric determination of aluminium in steel with stilbazo

A procedure for the determination of aluminium in steel is described. Aluminium is separated from iron and interfering elements by ion exchange in concentrated hydrochloric acid solution, and finally determined spectrophotometrically with stilbazo.     

EDTA滴定法连续测定铅精矿中铅和锌

建立了EDTA滴定法连续测定铅精矿中铅和锌的方法。试样用盐酸、硝酸、硫酸和氯酸钾分解。铅通过硫酸铅沉淀与其他干扰元素分离,沉淀溶解于乙酸-乙酸钠溶液中。在滤液中加入氨水、氟化钾使铁等干扰元素沉淀并与锌溶液分离。用二甲酚橙作指示剂,EDTA分别滴定溶液中的铅和锌。研究中测定了能力验证NILPT(2010)-0211铅精矿样品10-1和10-2中铅和锌,结果满意。     

Chelatometric titration of tin in non-ferrous alloys with hedta

A new titrimetric method for determination of tin (4%) in aluminium alloys, tin- and lead-base alloys, solders, white bearing alloys, special bronzes and silver brazing alloys is proposed. HEDTA, Semi-Xylenol Orange and bismuth perchlorate are used as titrant, indicator and back-titrant respectively. Measures are taken to overcome the hydrolysis of Sn(IV). Monochloroacetic acid and ethylene glycol are added as auxiliary agents. The standard deviation of this method was found to be 0.2 mg and its coefficient of variation to vary from 0.25 to 2%, according to amount of tin. A novel method of sample decomposition and a modified method for separating Sn(IV) are also suggested.     

Anion-exchange separation of cadmium in organic solvent-nitric acid media

The anion-exchange separation of cadmium from zinc and aluminium in organic solvent-nitric acid mixtures was studied. The distribution coefficients of the 3 elements in various 90% organic solvcnt-10% 5 N nitric acid media were determined for Dowex I-X8 resin. A 90% ethanol-10% 5 N nitric acid medium was most satisfactory for the quantitative separation of cadmium from zinc and aluminium. The method was applied to the analysis of some copper and aluminium base alloys. Methyl glycol or acetic acid could be used instead of ethanol. Both cadmium and zinc were strongly adsorbed from a 90% propionc acid-10% 5 N nitric acid medium; separation was then effected by gradient elution.     

A highly selective procedure for the spectrophotometric determination of aluminium with 8-hydroxy-quinoline and its application to the determination of

Aluminium, hydroxyquinolate can be quantitatively extracted by chloroform from an ammoniacal solution containing hydroxyquinoline, complexone and cyanide. Likewise extracted are titanium, vanadium, tantalum, niobium, uranium, zirconium, gallium, antimony, bismuth, indium and traces of beryllium. Aluminium can be separated from the first five elements by an extraction in ammoniacal solution containing hydrogen peroxide.Zirconium, gallium, bismuth and antimony can be eliminated by a cupferron extraction and indium by extraction with diethyldithiocarbamate. Beryllium is eliminated by performing an extraction with hydroxyquinoline at pH 5. The proposed method enables a practically specific photometrical determination of aluminium. Applications are given of the determination of trace and higher amounts of aluminium in steels, non-ferrous alloys and in glass.     

The polarographic determination of aluminium in zinc-base die-casting alloys

A procedure for the direct polarographic determination of aluminium is described, with particular reference to zinc-base die-casting alloys. Interfering elements are removed by electrolysis of a solution of the alloy in a mercury-cathode cell. The solution is polarographed at a carefully controlled pH in a supporting electrolyte of magnesium chloride and sodium sulfate of appropriate concentration. The precision and accuracy of the method are shown to be satisfactory by the analysis of standard samples from three different laboratories.     

EDTA滴定法测定再生锌原料中的锌含量

采用氟化铵-盐酸-硝酸-硫酸分解样品,氨水沉淀分离铁、锰、铅等共存元素,滤液中加入掩蔽剂掩蔽少量干扰元素,在pH=5～6的乙酸-乙酸钠缓冲溶液中,以二甲酚橙为指示剂,用EDTA标准滴定溶液滴定。测得结果为锌、镉合量,扣除镉量,即为锌量。方法用于测定再生锌原料中锌,结果的相对标准偏差(RSD,n=11)为0.15%～1.0%。按照实验方法对再生锌原料样品进行加标回收实验,回收率为99.1%～102%。能满足日常对再生锌原料中锌含量的检测要求。     

The differential pulse polarographic determination of trace amounts of tin and its application to zinc-aluminium alloys

A differential pulse polarographic procedure for the determination of 0.001-0.02% of tin in zinc-aluminium alloys is described. The tin is first separated from interfering elements such as copper and lead by homogeneous co-precipitation with aluminium succinate. The tin is determined polarographically in a 1M hydrochloric acid + 4M ammonium chloride electrolyte. After the tin has been masked with alkaline citrate a second polarogram is recorded to ascertain whether residual lead is present and, if so, a correction is applied.     

Determination of trace and minor elements in alloys by atomic-absorption spectroscopy using an induction-heated graphite-well furnace as atom source-II

Results are presented for the atomic-absorption spectrophotometric determination of zinc in aluminium and aluminium-silicon alloys, and aluminium, antimony and tin in steels, by means of solid samples dropped into an induction-heated graphite-well furnace to produce the atomic vapour.     

Microstructural characterisation of five simulated archaeological copper alloys using light microscopy, scanning electron microscopy, energy dispersive X-ray microanalysis and secondary ion mass spectrometry

This paper describes the microstructural characterisation of five simulated archaeological copper alloys, produced by modern powder technology. The chemical composition of the examined bronzes covers the major families of archaeological bronzes from antiquity until the Roman period. Light microscopy (LM), energy dispersive X-ray microanalysis (EDX), scanning electron microscopy (SEM) as well as two- and three-dimensional secondary ion mass spectrometry (SIMS) have been used to describe the main properties of the alloys. The results show a heterogeneous microstructure on a micrometer scale, formed by metallic and non-metallic phases. The latter are conglomerates of oxides or sulphides of major or minor elements.     

Universelles Verfahren zur Bestimmung des Aluminiums in natürlichen Materialien und technischen Produkten

The paper outlines what may be considered a universally applicable procedure for the determination of aluminium. It is based on a complexometric titration according to the NaF demasking technique employing voltametric indication. This is normally preceeded by chloroform extraction of elements which react with cupferron in strongly acidic solutions [e.g. Ti, Zr, Nb Fe(III), rare earth elements] and extraction of the aluminium itself (in the form of its cupferron complex) from acetic acid solution, chloroform again being employed as solvent, to effect separation from the alkaline earths. This latter extraction is necessary only where alkaline earths, in particular Ca, are present in excess of aluminium. Examples of application and detailed instructions are given for the determination of aluminium in rocks, limestone, iron ores, complex nickel basis alloys and titanium alloys. Although additions to the standard procedure may become necessary for certain sample compositions the standard process itself remains unchanged regarding the titration step. A high grade of accuracy (standard deviation of 0,03 for 10% of Al) and a wide range of application (0.005% of Al in limestone to 45% Al in Bauxite) are the advantages of the method proposed.     

Separation of rhenium from molybdenum, tungsten, vanadium, platinum metals and other elements by reduction and solvent extraction

Reduction in 1 M H(2)SO(4) with liquid zinc amalgam and extraction with isopentanol from 3M H(2)SO(4), separates rhenium from almost all the interfering elements of importance in rhenium determination. The small amounts of Mo, U, Fe and Ru still accompanying rhenium are removed by the thiocyanate-pentyl acetate or the oxine-chloroform extraction. The method is simple, rapid and of very wide applicability. It is particularly useful in the determination of rhenium in various alloys and tungsten-containing samples.     

Influence of grain orientation on zinc enrichment and surface morphology of an Al?Zn alloy

Zinc is an important alloying element in the 7000 series aluminium alloys. It is also an element that may enrich near the alloy surface during treatments of aluminium alloys by processes such as electropolishing, alkaline anodic etching and alkaline etching. The enrichment may occur since the change in Gibbs free energy per equivalent for formation of ZnO is less negative than that for formation of Al₂O₃. The enriched alloying element is present in an alloy layer up to ～5 nm thick located immediately beneath the alloy/film interface. In the present study, the dependence of the enrichment of zinc on the grain orientation of the alloy is investigated for a solid solution Al‐1.1at.%Zn alloy. The enrichment of the zinc is developed by alkaline etching of the alloy. The grain orientation is determined by electron backscattering diffraction, with enrichments quantified on selected grains by Rutherford backscattering spectroscopy and medium energy ion scattering. The morphologies of the surfaces of the etched grains are characterised by scanning electron microscopy and atomic force microscopy. The findings reveal that the zinc enrichment ranges from 1.7 × 10¹⁵ atoms/cm² to 3.9 × 10¹⁵ atoms/cm², with the greatest enrichment occurring on a grain of (100) orientation, while differing surface topographical textures are developed on the various grains. Copyright © 2009 John Wiley & Sons, Ltd.     

Fluorimetric determination of gallium in a nickel alloy and aluminium with N-oxalylamine(salicylaldehyde hydrazone)

A fluorimetric determination of gallium, based on the formation of the fluorescent chelate with N-oxalylamine(salicylaldehyde hydrazone) (OSH)-Ga(III), is proposed. The complex has excitation and emission maxima at 395 and 475 nm, respectively. The detection limit is 3 ng/ml and Ga can be determined up to 277 ng/ml. The method has been applied to the determination of gallium in a nickel alloy and aluminium. Extraction with n-butyl acetate from 6M hydrochloric acid medium has been used to separate Ga from the interfering elements in the alloys.     

Atomic-emission spectrometry with an induction-coupled high-frequency plasma source Comparison with the inert-gas shielded premixed nitrous oxide-acetylene flame for multi-element analysis

The performance for trace analysis in solution by atomic-emission spectrometry from a 36-MHz induction-coupled radiofrequency plasma atom-cell is predicted from a simple model and compared with the corresponding characteristics of an inert-gas shielded nitrous oxide-acetylene flame. A longer linear calibration range is predicted for the plasma source owing to the greater freedom from self-absorption under optimum operating conditions, and the long residence time of analyte species confers freedom from solute vaporization interferences. The predictions are verified experimentally and the advantages of the use of the plasma source are demonstrated in the analysis of aluminium alloys for copper, iron, magnesium, manganese, titanium and zinc.     

The determination of magnesium in the presence of large amounts of zinc: A spectrophotometric method

The spectrophotometric determination of magnesium in the presence of large amounts of zinc is described. Zinc as well as some other interfering metals are removed by mercury cathode electrolysis and aluminium is removed by a chloroform extraction with 8-hydroxyquinoline.     

Thin-layer chromatography of aluminium: quantitative densitometric determination of Fe2+, Ni2+, Cu2+, and Si4+

Thin-layer chromatography in combination with scanning densitometry is used as a tool for the quantitative determination of some impurity and additive elements in aluminium. Microgram levels of iron, silicon, copper, nickel, titanium, magnesium, manganese, and zinc present in a high concentration aluminium matrix is detected, and selective separations of some of these elements are achieved on silica gel H layers developed with a mobile phase containing aqueous sodium chloride solution. The quantitative determination of iron, silicon, nickel, and copper are obtained from the densitometric evaluation of chromatograms and are compared with the respective optical emission spectral analytical data.