DIN 51001-2003 Testing of oxidic raw materials and basic materials - General bases of work for X-ray fluorescence method (XRF)《氧化原材料和基础材料检验 X射线荧光法通用作业基础》.pdf

1、ICS 71.060.20Prfung oxidischer Roh- und Werkstoffe Allgemeine Arbeitsgrundlagen zurRntgenfluoreszenz-Analyse (RFA)In keeping with current practice in standards published by the International Organization for Standardization(ISO), a comma has been used throughout as the decimal marker.Ref. No. DIN 51

2、001 : 2003-08English price group 06 Sales No. 010606.04DEUTSCHE NORM August 2003 No part of this translation may be reproduced without the prior permission ofDIN Deutsches Institut fr Normung e.V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards

3、(DIN-Normen).Translation by DIN-Sprachendienst.In case of doubt, the German-language original should be consulted as the authoritative text.General procedures for the X-ray fluorescenceanalysis (XRF) of oxidic raw materialsContinued on pages 2 to 4.This standard,together with DIN EN ISO 12677,supers

4、edes DIN 51001-1,July 1983 edition.51001ForewordThis standard has been prepared by Technical Committee Chemische Analyse von oxidischen Roh- undWerkstoffen of the Normenausschuss Materialprfung (Materials Testing Standards Committee), taking intoaccount the specifications of DIN EN ISO 12677.The sta

5、ndard assumes a knowledge of the basic technical principles of X-ray fluorescence analysis (XRF)contained in the relevant literature and the instructions of the spectrometer manufacturers.AmendmentsThis standard differs from the July 1983 edition as follows:a) the scope has been amended to cover onl

6、y those points which are not dealt with in DIN EN ISO 12677;b) details relating to compensation for moisture in fluxes have been included;c) the standard has been editorially revised.Previous editionDIN 51001-1: 1983-07.1 ScopeThe XRF method specified in this standard serves to determine the oxide c

7、ontent of samples of predomi-nantly oxidic raw materials, excluding those specified in DIN EN ISO 12677, prepared by an appropriatemethod (as in DIN 51061-2, DIN 51061-3, DIN 51078 or ENV 1402-2), in concentrations ranging from thelimit of detection up to a proportion by mass of the original substan

8、ce of 100%. The analysis yields the totalcontent of a particular elemental oxide, regardless of the type of bonding.All the elements having an atomic number of 9 (fluorine) or above can be determined, but the analytical errorsand the associated limits of detection for each element will depend on the

9、 efficiency of the equipment, thetype of sample, sample preparation and the method of evaluation, and are therefore dealt with elsewhere.Page 2DIN 51001 : 2003-082 Normative referencesThis standard incorporates, by dated or undated reference, provisions from other publications. These norma-tive refe

10、rences are cited at the appropriate places in the text, and the titles of the publications are listed below.For dated references, subsequent amendments to or revisions of any of these publications apply to thisstandard only when incorporated in it by amendment or revision. For undated references, th

11、e latest edition ofthe publication referred to applies.Supplement 1 to DIN 51001 General test procedures for the X-ray fluorescence analysis (XRF) of oxidic rawmaterials Summary of fusion methods for the preparation of samples based onsubstance groupsDIN 51061-2 Sampling of ceramic raw materials and

12、 refractory unmoulded productsDIN 51061-3 Sampling and incoming inspection of moulded refractory productsDIN 51078 Preparation of refractory samples for the chemical analysis and for determiningthe change in mass on dryingDIN EN ISO 12677 Chemical analysis of refractory products by XRF Fused cast be

13、ad method(ISO 12677 : 2003)ENV 1402-2 Unshaped refractory products Part 2: Sampling3 Sampling and sample preparationUnless otherwise agreed upon, sampling shall be carried out as specified in the appropriate standard(DIN 51061-2, DIN 51061-3 or ENV 1402-2) and the analytical sample shall be prepared

14、 as described inDIN 51078.4 Surface finishXRF requires samples whose flat surface is representative of the composition of the analytical sample. Depend-ing on the material and on the permissible total uncertainty, this requirement can be met by grinding originalsamples, or by fusing powdered or cast

15、 material. The sample to be analysed and the reference sample shall beprepared in the same way.4.1 Original samplesSolid samples, such as glass and glass ceramics, that are sufficiently homogeneous and do not give rise toeffects due to particle size and crystal structure may be analysed in their ori

16、ginal state. Otherwise, one of thetechniques described in subclauses 4.2 to 4.4 are to be adopted for sample preparation.4.2 PelletsHeterogeneous samples may be reduced in size and converted to pellet form. Whether this type of sample canbe used will depend on particle size distribution, particle co

17、mposition, crystal structure effects, wavelength ofanalytical line and permissible total uncertainty.4.3 Fused beadsConsidering all the advantages and disadvantages, the use of fused beads is recommended. The flux chosenshall produce a clear, homogeneous melt that does not crack on cooling, an advan

18、tage of this procedure beingthe possibility of preparing synthetic reference samples.A summary of standard fusion methods for preparing samples of some important substance groups for XRFconforming to this standard will be found in Supplement 1 to DIN 51001.4.4 Special samplesSpecial samples are samp

19、les in the form of solutions, precipitates and dust on filters.5 Sample treatment5.1 GeneralSurface quality requires particular attention when analysing for elements of atomic number less than 18.5.2 Pretreatment of original samplesThe sample shall be machined to fit the sample holder and its surfac

20、e shall be ground flat, finely ground and,if necessary, polished.Page 3DIN 51001 : 2003-085.3 Preparation of pelletsAfter any drying or ignition process necessary, an analytical sample (finished sample) prepared as specified inDIN 51078 (maximum particle size 0,063 mm) shall be finely ground, the re

21、quired analytical substance andadditives (diluents or binders) determined by weighing, the sample material homogenized if necessary, and thepowder thus produced converted to a pellet. The required grinding and pressing parameters (sample size,grinding aids, grinding time and pressure, holding time,

22、use of supports), to be determined experimentally, shallbe kept constant.5.4 Fused beads5.4.1 FluxThe purpose of fusion is to convert the analytical material and a flux into a homogeneous melt that forms a glassysolid on cooling. In addition to eliminating the effect of particle size distribution an

23、d the mineralogical compo-sition of the sample on the radiation intensity, fusion results in a uniform bonding of the elements and theassociated dilution reduces interaction between the elements due to secondary excitation and absorption.Fluxes are composed of elements that are not to be determined

24、during the analysis. On their own and togetherwith the sample material, they shall be able to form a stable homogeneous glass and be as stable as possiblewhen stored in a desiccator. These requirements are best fulfilled by lithium tetraborate, Li2B4O7, and sodiumtetraborate, Na2B4O7, fused beads of

25、 the former having a lower moisture absorption than those of the latter.Lithium tetraborate and sodium tetraborate supplied by a number of reagent manufacturers especially forX-ray fluorescence analysis are to be given preference to ungraded borates because of their high purity, theirhigh bulk densi

26、ty and excellent processability. Their water content is low in their as delivered condition and evenstorage in air increases it only slightly. To reduce the melt viscosity and fusion temperature or for the purposeof oxidative decomposition, carbonates, nitrates, fluorides, or lithium or sodium metab

27、orates may be addedin quantities small enough not to impair the quality of the glass formed. Other additives will be necessary onlyin special cases. Excessive quantities of additives result in crystallization and cracking of the beads.The same batch of flux shall be used for the reference and analyt

28、ical samples. The batch size shall thereforebe sufficient for several weeks or a few months. Every batch shall be homogenized as far as possible andchecked for impurities and changes in mass on ignition at fusion temperature.The flux contains a certain amount of moisture, which shall be compensated

29、for in one of two ways.a) Calcine the entire quantity of flux required overnight at 700 C immediately before it is used for analysis,and afterwards store it in a desiccator.b) Carry out duplicate loss on ignition tests using 1 g portions of well-mixed flux for each kilogram of fluxused. Calcine the

30、flux samples at the normal fusion temperature, either for ten minutes or for the standardfusion time, whichever is longer. When not in use, keep the flux in a tightly sealed container. The loss onignition, L, expressed as a percentage, is then to be used to calculate a factor, F (see equation below)

31、, whichis in turn used to calculate the mass of unignited flux needed to produce the required mass of ignited flux(F required mass of ignited flux = required mass of unignited flux). Determine the loss on ignition at weeklyintervals or for each kilogram of flux used, whichever is the more frequent.1

32、00F =100 LThe compensation may be unnecessary if the loss on ignition is less than or equal to 0,50% (pre-fused fluxes).5.4.2 FusionThe sample to be analysed shall be prepared as specified in clause 3. It shall then be weighed to an accuracyof 0,1 mg in ignited or unignited form, depending on the ma

33、terial (allowance being made, if appropriate, for thepreviously determined loss on ignition) and mixed thoroughly with flux, likewise weighed to an accuracy of0,1 mg. The total initial mass shall be sufficient to produce a fused bead a few millimetres thick. The fusion shallbe performed in a PtAu5 c

34、rucible (if necessary, covered) at temperatures between 900 C and 1 150 C on gasburners or in an electrically heated furnace, heating particularly slowly at first if volatile components are present.During fusion, the crucible shall be swirled several times to homogenize the melt. Depending on the sa

35、mplematerial, the melt shall be free of residues, bubbles or strias after five to twenty minutes.5.4.3 Casting of beadsThe melt shall be poured on a preheated plate or cast into a preheated mould made of PtAu5 or other materialsuitable for preparing fused beads having similar surfaces. If crucibles

36、with a mould are used, the castingoperation will be unnecessary. Rapid cooling with an air jet, starting from the centre of the base produces stablebeads. A water-cooled steel plate may also be used for this purpose.Page 4DIN 51001 : 2003-086 MeasurementAfter the XRF spectrometer has been made ready

37、, the finished samples shall be introduced and placed in themeasurement position.Depending on the type of spectrometer, the signal intensities of the elements shall be determined simulta-neously or sequentially, the measurement time depending on the intensities. The spectrometer settings shallbe cho

38、sen to suit the particular analytical problem, taking into account the recommendations of the equipmentmanufacturer. Samples of unknown composition shall be subjected to a preliminary qualitative analysis in orderto detect any possible line overlaps. The primary analytical signal shall be obtained i

39、n the form of pulses overa given measurement time or as a measurement time for a given number of pulses, and the pulse rate used forthe subsequent evaluation.Reference samples shall be analysed under the same conditions.7 EvaluationThe results for the analytical and reference samples shall be used to calculate the analytical result as a percent-age.