1、Designation: D7085 04 (Reapproved 2010)1Standard Guide forDetermination of Chemical Elements in Fluid CatalyticCracking Catalysts by X-ray Fluorescence Spectrometry(XRF)1This standard is issued under the fixed designation D7085; the number immediately following the designation indicates the year ofo
2、riginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEUpdated Scope and text to reflect the use of ppm and SI units edito
3、rially in April 2010.1. Scope1.1 This guide covers several comparable procedures for thequantitative chemical analysis of up to 29 elements in fluidcatalytic cracking (FCC) catalyst by X-ray fluorescence spec-trometry (XRF). Additional elements may be added.1.2 This guide is applicable to fresh FCC
4、catalyst, equilib-rium FCC catalyst, spent FCC catalyst, and FCC catalyst fines.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3.1 The units of ppm (mg/kg) are used instead of wt% inTables X2.3-X2.5 for reporting concentr
5、ation of certain ele-ments because of industry convention and because most ofthese elements are present at trace levels.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-pr
6、iate safety and health practices and determine the applica-bility of regulatory requirements prior to use.2. Referenced Documents2.1 ASTM Standards:2C982 Guide for Selecting Components for Energy-Dispersive X-Ray Fluorescence (XRF) Systems3C1118 Guide for Selecting Components for Wavelength-Dispersi
7、ve X-Ray Fluorescence (XRF) SystemsD1977 Test Method for Nickel and Vanadium in FCCEquilibrium Catalysts by Hydrofluoric/Sulfuric Acid De-composition and Atomic Spectroscopic AnalysisE1172 Practice for Describing and Specifying aWavelength-Dispersive X-Ray SpectrometerE1361 Guide for Correction of I
8、nterelement Effects inX-Ray Spectrometric AnalysisE1621 Guide for X-Ray Emission Spectrometric AnalysisE1622 Practice for Correction of Spectral Line Overlap inWavelength-Dispersive X-Ray Spectrometry33. Summary of Guide3.1 The test specimen is prepared with a clean, uniform, flatsurface. Two common
9、ly used test methods of preparing testspecimens are listed: briquetting a powder (Test Method A,Sections 8-15) and fusing a powder into a glass bead (TestMethod B, Sections 16-23). This surface of the fused orbriquetted specimen is irradiated with a primary source of Xrays. The secondary X rays prod
10、uced in the specimen arecharacteristic of the chemical elements present in the speci-men. Two types of XRF instrumentation may be used to collectand process the X-ray spectra. Using a wavelength-dispersiveX-ray spectrometer, the secondary X rays produced in thespecimen are dispersed according to the
11、ir wavelength bymeans of crystals or synthetic multilayers. The X-ray intensi-ties are measured by detectors set at selected wavelengths andrecorded as counts (number of X rays impinging on thedetector per unit time). Concentrations of the elements aredetermined from the measured intensities using c
12、alibrationcurves prepared from suitable reference materials. Using anenergy-dispersive X-ray spectrometer, the secondary X raysproduced in the specimen are sent to a detector where the entireX-ray spectrum is electronically sorted according to the X-ray1This guide is under the jurisdiction of ASTM C
13、ommittee D32 on Catalysts andis the direct responsibility of Subcommittee D32.03 on Chemical Composition.Current edition approved April 1, 2010. Published May 2010. Originallyapproved in 2004. Last previous edition approved in 2004 as D7085041.DOI:10.1520/D7085-04R10E01.2For referenced ASTM standard
14、s, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm
15、.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.energy and processed into counts using a multichannel ana-lyzer. The principal advantages of the wavelength-dispersiveX-ray spectrometer are resolution and detection limit. Theprin
16、cipal advantages of the energy-dispersive X-ray spectrom-eter are speed and a generally lower equipment cost.4. Significance and Use4.1 The chemical composition of fresh FCC catalyst andequilibrium FCC catalyst is a predictor of catalyst perfor-mance. The analysis of catalyst fines also provides inf
17、ormationon the performance of the FCC unit and the fines collectiondevice(s).4.2 The chemical composition of equilibrium FCC catalystis a measure of the hazardous nature or toxicity of the materialfor purposes of disposal or secondary use.5. Apparatus5.1 X-ray Spectrometer, wavelength or energy-disp
18、ersivesystem equipped with a vacuum sample chamber. Refer toGuide C982, Guide C1118, and Practice E1172 for informationon specifying XRF systems.5.2 Muffle Furnace, capable of operating at 600C.5.3 Hot Plate, capable of maintaining a constant 200C.5.4 Porcelain Dishes, of a suitable size for calcini
19、ng 50-gsample aliquots.5.5 Vacuum Oven, capable of maintaining 60C. This isrequired only if catalyst fines are to be analyzed.5.6 Vacuum Desiccators, useful for storing fusion beads orpressed pellets.5.7 Fusion Equipment:5.7.1 Fusion Furnace or Fluxing Device, capable of oper-ating at 1100C.5.7.2 Fu
20、sion Crucibles and Molds, graphite or plati-num5 % gold alloy, sized to match the specimen holder of theX-ray spectrometer.5.8 Pressed Pellet Equipment:5.8.1 Grinders or Pulverizers, manual (such as agate, mul-lite, alumina, tungsten carbide, or boron carbide mortar andpestle) or automated (typicall
21、y with a tungsten carbide grindingvessel). Avoid steel grinding vessels.5.8.2 Mixer Mill, useful for blending ground sample andbinder prior to preparing a pressed powder specimen.5.8.3 Mixing Vials, sized to match the mixer mill.5.8.4 Briquetting Press, capable of maintaining a reproduc-ible pressur
22、e of at least 25 000 psi. This is required only if thepressed powder method is utilized. Match mold size to thespecimen holder of the X-ray spectrometer. Typical sizes are 25to 40 mm.6. Reagents6.1 Reagents for Fusion Techniques:6.1.1 Fluxes, lithium borates or carbonates or mixtures, ofultrahigh pu
23、rity.6.1.2 Non-Wetting Agents, such as lithium or ammoniumiodide, are frequently added to the flux, as are oxidizing agentssuch as lithium, potassium, or ammonium nitrate. Take carethat adding non-wetting or oxidizing reagents does not causespectral interference with the analytes of interest.6.2 Rea
24、gents for Pressed Pellet Techniques:6.2.1 Heavy Absorber, barium or hafnium oxides are com-monly used as heavy absorbers, if that technique is applied.6.2.2 Binders, required for the pressed powder technique.These should not contribute any spectral interference. Micro-crystalline wax or cellulose wi
25、th negligible levels of sodium orpotassium are suitable.6.3 Detector Gas, for a wavelength dispersive system. Thetypical gas for the flow-proportional counter is P-10: 10 %methane and 90 % argon.6.4 2-propanol, ACS reagent grade.6.5 Calibration References, commercially available stan-dard or certifi
26、ed reference materials or locally prepared mix-tures from ultra high purity materials that include the elementsof interest in the concentration ranges expected in unknownsamples.6.6 Standard Solutions, 10 000 g/mL of nickel and 10 000g/mL of vanadium.7. Procedure7.1 Prepare specimens using either a
27、pressed powder or afusion technique.7.2 Prepare calibration standards using the same techniquesand reagents that will be used with the unknown samples.7.2.1 Calibration standards can be prepared from previouslyanalyzed samples where the accuracy and precision of theanalysis is known. This is the typ
28、ical calibration method for thepressed powder technique. Up to 100 analyzed standards maybe required for a full range calibration for 29 elements usingthe pressed powder technique.7.2.2 Synthetic standards can be prepared from reagent-grade chemicals, analyzed samples, and certified referencemateria
29、ls. This is the typical calibration method for the fusiontechnique.7.3 Several tables, listed in Appendix X1, provide operatinginformation on the requirements necessary to establish apressed powder method for 29 elements in equilibrium FCCcatalyst.TEST METHODSTest Method APressed Powder8. Scope8.1 A
30、 test method example is provided for the analysis ofnickel and vanadium in equilibrium FCC catalyst using eithera wavelength or an energy-dispersive X-ray spectrometer andtest specimens prepared by the pressed pellet technique.8.2 This technique can be extended to other elements.9. Significance and
31、Use9.1 In use, the FCC catalyst becomes contaminated withmetals present in the feed oil. The levels of the contaminantmetals, particularly the catalyst poisons nickel and vanadium,can be used to predict catalyst performance.10. Hazards10.1 Catalyst dust.10.2 X-ray radiation.D7085 04 (2010)1210.3 Hea
32、t.10.4 High pressure.11. Preparation of Apparatus11.1 Select the appropriate instrument for either awavelength-dispersive or energy-dispersive technique. Forthese examples, use of energy-dispersive systems for analytesbelow 0.1 wt% would prove difficult. Assuming the FCCcatalyst contains rare earths
33、, the difficulty increases because,by energy-dispersive X-ray fluorescence spectrometry(EDXRF), rare earths are poorly resolved and create significantmatrix effects.11.2 Read Guide E1621, Guide E1361, and Practice E1622.These will provide a general knowledge of the function of awavelength-dispersive
34、 X-ray spectrometer.11.3 Set up the instrument using the vendors manual.Modern X-ray spectrometers are equipped with software thatguides the operator through the steps necessary to create ananalytical program for a specific analysis. For this example,analysis of equilibrium FCC for nickel and vanadi
35、um, typicalinstrument conditions are given in Appendix X1.12. Calibration and Standardization12.1 Preparation of Calibration Standards:12.1.1 Assemble a minimum of five catalyst samples withnickel and vanadium concentrations that cover the range ofinterest. This test method is specific for a single
36、grade ofcatalyst and is limited to material where only the nickel andvanadium content varies.12.1.2 Prepare each catalyst sample in duplicate in accor-dance with Section 13, saving a portion of the calcined andground specimen for the next step.12.1.3 Determine the nickel and vanadium content of them
37、aterials prepared in 12.1.2 using a comparative analyticaltechnique such as Test Method D1977.12.2 Calibrate the instrument using the prepared standardsfollowing the vendors recommended procedure.13. Preparation of the Test Specimen13.1 Heat approximately 50 g of specimen in a mufflefurnace at 600C
38、with a bed depth less than 25 mm for aminimum of 1 h, if it is fresh catalyst, or up to3htoremovecarbon from spent catalyst, equilibrium catalyst, or catalystfines.13.2 Grind approximately 20 to 30 g of the heated specimento less than 30 m. Homogenize the material if it was groundin several batches.
39、13.3 Combine the ground specimen with binder at a prede-termined ratio into a mixing vial with mixing beads added topromote agitation. Typically, the binder is blended at a ratio of1 part binder to 3 to 5 parts sample and chosen to giveconsistent and stable pellets.NOTE 1As an example, 1.5 6 0.01 g
40、of a micronized high molecularweight paraffin wax binder is mixed with 6.5 6 0.01 g of the groundspecimen.13.4 Place the mixing vial into a mixing mill for 10 min tothoroughly mix/blend the specimen and binder.13.5 Place the contents of the mixing vial onto a piece ofweighing paper. Remove and disca
41、rd the mixing beads.13.6 Transfer the contents of the weighing paper to thebriquetting press, which has been previously cleaned with2-propanol, and spread evenly over the surface of the mold oroptionally press into an aluminum cap.13.7 Press the specimen at a ram pressure of between25 000 and 60 000
42、 psi. The pressure used will depend on thebinder and binder/sample ratio and is usually determinedempirically. For this binder example, a typical ram pressure is30 000 psi for 10 6 2 s for a 40-mm mold.13.8 Attach an identifying label to the backside of the pellet.Typically, the top surface is the a
43、nalytical surface. Avoidtouching this surface when handling the briquetted pellet.13.9 Store the pressed powder specimens in a vacuumdesiccator to prevent moisture pickup or contamination prior toanalysis.14. Procedure14.1 Analyze the prepared specimens following the ven-dors recommended procedure u
44、sing the calibration establishedpreviously in 12.2.15. Precision and Bias15.1 The precision values listed in Table 1 were obtainedfrom one sample of equilibrium FCC catalyst, prepared andanalyzed 16 times. The % relative standard deviation (RSD) isdefined as:%RSD 5 s / mean concentration! 3 100Test
45、Method BFused Bead16. Scope16.1 A test method example is provided for the analysis ofnickel and vanadium in equilibrium FCC catalyst using eitherTABLE 1 Precision ValuesMean Concentration, % 62 s (95 % C.I.) %RSDAl2O329.92 0.16 0.27SiO265.48 0.49 0.37Ni 0.2332 0.0051 1.1V 0.2417 0.0028 0.58Fe 0.54 0
46、.01 0.78Cu 0.0045 0.0002 1.7TiO21.03 0.01 0.49Mn 0.0040 0.0003 4.1Co 0.0142 0.0006 2.0Na 0.60 0.01 0.73MgO 0.085 0.004 2.5P2O50.340 0.009 1.2CaO 0.16 0.005 1.7SO40.17 0.01 2.3Sb 0.0862 0.0013 0.77ZnO 0.0255 0.0007 1.4Pb 0.0077 0.0002 1.4Ba 0.030 0.002 3.3La2O30.84 0.01 0.47CeO20.37 0.01 1.3Nd2O30.42
47、 0.01 0.93Pr6O110.13 0.01 2.3Sm2O30.01 0.001 6.0Total REO 1.77 0.01 0.60K2O 0.10 0.002 0.92Sr 0.011 0.001 2.9Zr 0.009 0.001 6.0D7085 04 (2010)13a wavelength or an energy-dispersive X-ray spectrometer andusing test specimens prepared by the fused bead technique.17. Significance and Use17.1 In use, th
48、e FCC catalyst becomes contaminated withmetals present in the feed oil. The levels of the contaminantmetals, particularly the catalyst poisons nickel and vanadium,can be used to predict catalyst performance.18. Hazards18.1 Catalyst dust.18.2 Flux dust.18.3 Heat.18.4 X-ray radiation.19. Preparation o
49、f Apparatus19.1 Select the appropriate instrument for either awavelength-dispersive or energy-dispersive technique. Forthese examples, use of energy-dispersive systems for analytesbelow 0.1 wt% would prove difficult. Assuming the FCCcatalyst contains rare earths, the difficulty increases because,by EDXRF, rare earths are poorly resolved and create signifi-cant matrix effects.19.2 Read Guide E1621, Guide E1361, and Practice E1622.These will provide a general knowledge of the function of awavelength-dispersive X-ray spectrometer.19.3 Set up the instrument using
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