1、Designation: C 1110 03Standard Practice forSample Preparation for X-Ray Emission SpectrometricAnalysis of Uranium in Ores Using the Glass Fusion orPressed Powder Method1This standard is issued under the fixed designation C 1110; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the preparation of uranium oresamples
3、to be analyzed by X-ray emission. Two separatetechniques, the glass fusion method or the pressed powdermethod, may be used.1.2 The values stated in SI (metric) units are to be regardedas the standard.1.3 This standard does not purport to address all of thesafety problems, if any, associated with its
4、 use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:E 50 Practices for Apparatus, Reagents, and Safety Precau-tions for Chemi
5、cal Analysis of Metals2E 135 Terminology Relating to Analytical Chemistry forMetals, Ores, and Related Materials23. Terminology3.1 DefinitionsRefer to Terminology E 135 for terms usedin this practice.4. Summary of Practice4.1 Two types of specimen preparation methods are offered.These are the glass
6、fusion technique and the pressed powdertechnique. The glass fusion specimens are fused and cast intodisks in a platimum-gold alloy crucible in the presence of anoxidizing agent at a preset temperature and time. The pressedpowder specimens are ground in a mill to a specified particlesize and briquett
7、ed into a solid specimen possessing a flathomogeneous surface to be analyzed.5. Significance and Use5.1 This practice is useful for the preparation of specimensof ore bodies for the analysis of uranium by X-ray emission.Two separate preparation techniques are described.6. Apparatus6.1 Platimum-Gold
8、Crucible, 95 % platinum 5 % gold, withflat 32-mm diameter bottom.6.2 Muffle Furnace, 1200C capacity with controller of610C resolution, or fusion apparatus with similar capabili-ties.NOTE 1A fusion apparatus may be substituted for the muffle furnacethroughout this practice. If such is used, follow th
9、e manufacturersoperating instructions.6.3 Rotary Swing Mill, with tungsten or boron carbide vials.6.4 Pellet Die, 32-mm diameter.6.5 Hydraulic Press, 25-ton capacity.6.6 Crucible, porcelain, Coors, 30-mL capacity.6.7 Refractory Brick, 60 to 70 % alumina firebrick.6.8 Analytical Balance, accurate to
10、60.001 g.7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society, wheresuch specifications are a
11、vailable.3Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination (see Practices E 50).7.2 Lithium Tetraborate(Li2B4O7), anhydrous, spectro-graphic grade.7.3 Oxidizing Agent, ammoniu
12、m nitrate (NH4NO3).7.4 Ethanol, anhydrous.1This practice is under the jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved July 10, 2003. Published September 2003. Origianllyapproved in 1988. Last p
13、revious edition approved in 1997 as C111088(1997)e1.2Annual Book of ASTM Standards, Vol 03.05.3“Reagent Chemicals, American Chemical Society Specifications,” Am. Chemi-cal Soc., Washington, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see “Reagent Chemic
14、als and Standards,” by JosephRosin, D. Van Nostrand Co., Inc., New York, NY, and the “United StatesPharmacopeia.”1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.5 Binding Agent, for example, pelletizing grade graphitepowder, cellul
15、ose powder, “Somar Mix,” or equivalent.7.6 Boric Acid, 99.9 % pure.8. Preparation of Standards and Specimens8.1 Glass Fusion Method:8.1.1 Ignition Loss of Lithium Tetraborate:NOTE 2Commercially availabe fused and ground lithium tetraboratemay be used, and only the 105C drying step is required.8.1.1.
16、1 Heat a 95 % platinum/5 % gold crucible in a mufflefurnace at 1100C for at least 10 min and cool to roomtemperature in a dessicator.8.1.1.2 Weigh the cooled crucible on an analytical balanceto 60.001 g (W1).8.1.1.3 Add to the tared crucible approximately5goflithium tetraborate weighed to the neares
17、t 60.001 g ( W2).8.1.1.4 Heat the crucible plus lithium tetraborate in themuffle furnace at 1100C for 15 min.8.1.1.5 Remove the crucible from the furnace, cool, andstore in a desiccator.8.1.1.6 Weigh the crucible plus the ignited lithium tetrabo-rate on an analytical balance to 60.001 g (W3).8.1.1.7
18、 Calculate the ignition factor in accordance withSection 9.8.1.1.8 Remove the lithium tetraborate glass by invertingthe crucible and tapping lightly on the bottom. Save this pelletto use as a blank in future calibrations.8.1.1.9 Clean the platinum crucible.8.1.1.10 Determine the loss on ignition for
19、 samples byfollowing 8.1.1.1 through 8.1.1.7, except ignite 2.0 g of samplein a porcelain crucible.NOTE 3Moist specimens should be previously dried at 105C for 1 h,and the loss on drying should be recorded.8.1.2 Specimen Fusion:NOTE 4Numerous ores contain sulfide minerals which at high tem-peratures
20、 will attack the platinum/gold crucible. For specimens thatcontain sulfide minerals, pre-oxidize a 2-g specimen plus 1.000 g ofammonium nitrate in a porcelain crucible for 15 min at 1100C. Cool theporcelain crucible, and then use the pre-oxidized material as the specimenand proceed with 8.1.2.1. Ore
21、s that contain high concentrations of alkalielements may attack porcelain crucibles; therefore, graphite crucibles arerecommended for this pre-oxidation step.8.1.2.1 Weigh 2.000 g of the specimen into a tared porcelaincrucible and ignite at 1100C for 15 min. Cool and reweigh thecrucible and specimen
22、.8.1.2.2 Weigh 5.000 g of loss-free equivalent lithium tet-raborate (determined from igniting the lithium tetraborate),1.000 g of ignited specimen, and 0.5000 g of ammoniumnitrate, all to the nearest 0.001 g.8.1.2.3 Transfer all three components into a 95 % platinum/5 % gold crucible and briefly mix
23、.8.1.2.4 Place the crucible and contents in a muffle furnace at1100C and fuse for 5 min.8.1.2.5 Remove the crucible from the furnace with longcrucible tongs and swirl the molten material to ensure completesolution and eliminate bubbles.8.1.2.6 Replace the crucible in the furnace for another 5min.8.1
24、.2.7 Repeat 8.1.2.5 and 8.1.2.6 until all of the specimenis dissolved.8.1.2.8 Remove the crucible from the furnace, place on arefractory brick, and allow it to cool to room temperature.8.1.2.9 When the crucible is cool, invert and lightly tap it tofree the glass disk.8.1.2.10 Clean the crucible.8.2
25、Pressed Powder Method:8.2.1 Grind a representative portion of the specimen weigh-ing at least5gto44m(325 mesh).4Mix the resultingpowdered specimen if necessary.NOTE 5Grinding aids may improve grinding time and efficiency.58.2.2 Press5goftheground specimen at 25 tons for 30 s.Use a suitable pelletizi
26、ng agent, if necessary.8.2.3 Clean the mill and die to avoid contaminating the nextspecimen. Brush any remaining powder residue from the milland wipe out remaining traces with a paper towel wetted witha suitable solvent such as ethanol. Clean the die assembly in asimilar manner.8.3 Prepare all calib
27、ration standards using the same methodas used for specimen preparation.9. Calculation9.1 Ignition Factor Calculate the ignition factor as fol-lows:IF 5 W32 W1!/W22 W1! (1)where:IF = ignition factor,W1= weight of crucible, g,W2= weight of crucible and fusion powder before igni-tion, g, andW3= weight
28、of crucible and fusion powder after ignition,g.10. Precision and Bias10.1 No statement is made about the precision or the bias ofthis practice since this practice addresses only preparation forspecimen analysis, and therefore no data are generated.11. Keywords11.1 glass fusion; pressed powders; samp
29、le preparation;uranium ores; x-ray fluorescence4Wheeler, B., “Particle Size Effects in X-ray Fluorescence Analysis,” Advancesin X-ray Analysis, Proceedings of the 32nd Annual Conference on Application ofX-ray Analysis, Vol 27, Denver, CO, Aug 1984.5Berstein, F., “Particle Size and Mineralogical Effe
30、cts in Mining Applications,”11th Annual Conference on Application of X-ray Analysis, Denver ResearchInstitute, University of Denver, Denver, CO, 1962.C1110032ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standa
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