1、Designation: D 4481 04Standard Test Method forTotal Nickel in Fresh Alumina-Base Catalysts1This standard is issued under the fixed designation D 4481; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A num
2、ber 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 test method covers the determination of nickel infresh alumina-base catalysts and has been tested at nickelconcentrations from 2.5 t
3、o 60 weight %, expressed as nickeloxide (NiO).1.2 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-priate safety and health practices and determine the applica-bility of regul
4、atory limitations prior to its use.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterE 105 Practice for Probability Sampling of MaterialsE 177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE 456 Terminology for Relating to Quality and StatisticsE
5、691 Practice for Conducting an Interlaboratory Study toDetermine Precision of a Test Method3. Summary of Test Method3.1 The test specimen (as received) is treated with concen-trated hydrochloric acid to solubilize the nickel. If necessary,nickel is recovered from any insoluble residue by potassiumpy
6、rosulfate fusion, after hydrofluoric-sulfuric acid treatment toremove silica. Ammonium citrate is added to complex thealuminum and buffer the solution. Nickel is precipitated asnickel dimethylglyoxime, Ni (C4H7O2N2)2, at a weakly alka-line pH. The precipitate is washed and weighed as Ni(C4H7O2N2)2af
7、ter drying at 120C.3.2 A separate test specimen is taken to determine loss onignition (LOI) at 550C. The value is used to calculate thenickel as percent nickel oxide (NiO) on a 550C dry basis.4. Significance and Use4.1 This test method sets forth a procedure by whichcatalyst samples can be compared
8、either on an interlaboratoryor intralaboratory basis. It is anticipated that catalyst producersand users will find this method of value.5. Interferences5.1 Cobalt, molybdenum, and aluminum do not interfere.Interferences by elements that precipitate as hydroxides, suchas iron, chromium, aluminum, lea
9、d, tin, manganese, titanium,and zirconium, are avoided by the addition of ammoniumcitrate before making the solutions ammoniacal. Copper,present in the 2 to 10 % range, tends to be co-precipitated withthe nickel dimethylglyoxime. The only other metal ions pre-cipitated by dimethylglyoxime are pallad
10、ium, gold, and bis-muth.6. Apparatus6.1 Beakers, 600-mL, 150-mL.6.2 Hotplate.6.3 Furnace, electric muffle. Calibrated and capable ofmaintaining temperatures of 550 6 25C, and 950 6 25C.6.4 Platinum Dishes, 100-mL3capacity.6.5 Mortar and Pestle, agate, or equivalent mechanicalgrinder.6.6 Crucibles, s
11、intered-glass, 30-mL, medium porosity frit.6.7 Fiberglass Filter, 3.2 cm.6.8 Drying Oven capable of maintaining a temperature of120C.6.9 Vacuum Filtering Flask, 500-mL.6.10 Filter Holder and Filter Disk, Millipore 0.65 m-47-mm diameter.6.11 pH Paper to detect a value of 9.6.12 Screen, 250-m openings
12、, 60-mesh.6.13 Analytical Balance, capable of weighing to nearest 0.1mg.6.14 Ashless Filter Pulp.6.15 Desiccator.1This test method is under the jurisdiction of Committee D32 on Catalysts andis the direct responsibility of Subcommittee D32.03 on Chemical Composition.Current edition approved April 1,
13、2004. Published April 2004. Originallyapproved in 1985. Last previous edition approved in 1997 as D 448197.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the stand
14、ards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7. Reagents7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reag
15、ents shall conform to the specifications of the Commit-tee on Analytical Reagents of the American Chemical Society,where such specifications are available.3Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lessening the
16、accuracy of the determination.7.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean type IV reagent water asdefined in Specification D 1193.7.3 Ammonium Citrate, dibasic crystal, (NH4)2HC6H5O7.7.4 Ammonium Hydroxide, 10 and 25 % solutions.7.5 Hydrochloric Acid
17、, concentrated 38 %.7.6 Hydrofluoric Acid, concentrated 48 %.7.7 Methyl Red Indicator (o-carboxy benzeneazodimethylaniline)Dissolve 0.02 g in 60-mL reagent gradeethanol. Add 40.0 mL of distilled water.7.8 4A Molecular Sieve, activated for2hat275C.7.9 Potassium Hydrogen Sulfate, fused power-acid-flux
18、grade.7.10 Sodium Dimethylglyoxime, 8-Hydrate, crystal,CH3C:NONaC:NONaCH38H2O. Prepare a 1 weight % pervolume solution in water.7.11 Sulfuric Acid, 10 and 50 % solutions.NOTE 1The sodium salt of dimethylglyoxime is recommended, ratherthan the organic reagent, dimethylglyoxime because the salt is wat
19、ersoluble. Large excesses added to precipitate the nickel do no harm as theexcess dimethylglyoxime is eliminated during the filtration and washingpart of the procedure. The organic reagent, dimethylglyoxime, is not verysoluble in water and is often added as a 1 % solution in ethanol. Whenadded in th
20、is way, some of the excess reagent may contaminate theprecipitated nickel complex. For this reason an aqueous solution of thesodium salt is preferred. If the alcohol solution of dimethylglyoxime is tobe used, add an amount so that the alcohol content of the sample solutiondoes not exceed 50 % or som
21、e of the precipitated nickel dimethylglyoxy-mate may dissolve.8. Sampling8.1 The selection of a representative analytical sample fromthe bulk material is outside the scope of the present testmethod. It is presumed that parties using this test method forcomparison purposes will have agreed on the sel
22、ection of ananalytical sample. If a sampling procedure is desired, PracticeE 105 is recommended.8.2 Grind the sample to pass through a 60-mesh screen.9. Procedure9.1 Weigh three test specimens sufficient to yield 50 to 75mg of NiO into 150-mL beakers. Record mass to the nearest0.1 mg as G.9.2 Weigh
23、three 1-g test specimens into platinum dishes orporcelain crucibles. Record mass to the nearest 0.1 mg as G1.Calcine for2hina550C muffle furnace. Transfer to adesiccator containing freshly activated 4A molecular sieve.Cool, weigh, record mass as G2, and calculate percent solids.9.3 To test specimens
24、 from 9.1, add 20-mL of concentratedhydrochloric acid and heat gently on a hotplate until only apaste of solids is left. Do not boil the solution. Do not bakesolids or subsequent re-solution will be difficult.9.4 Add 20 mL of concentrated hydrochloric acid and warmon a hotplate 15 to 30 min to disso
25、lve salts. Cool and dilute toabout 100 mL with deionized water.9.5 Filter solids on 0.45-m filter, using a 500-mL filterflask as a receiver. Wash the beaker with four approximately20-mL portions of deionized water, transferring the washes tothe filter. Wash the solids on the filter with three more 2
26、0-mLportions of deionized water. Quantitatively transfer the filtrateplus washes to a 600-mL beaker. Keep the beaker covered untilready to precipitate nickel.9.6 Put a filter disk into a platinum dish and cover withashless filter pulp. Carefully char over a gas burner, then igniteat red heat until t
27、he carbon is essentially burned off. Put thedish in a muffle furnace at 960C for 50 min.9.7 To solids in the platinum dish, add 10 mL of 48 %hydrofluoric acid and 5 mL of 10 % sulfuric acid and evaporatecarefully to dryness on a hotplate. Then, carefully bring to a redheat over a gas burner until th
28、e sulfur trioxide fumes cease.Cool and add5gofreagent potassium pyrosulfate and fuseover a gas burner until a clear melt is obtained. Cool, add 10mL of 10 % sulfuric acid, 20 mL of deionized water, and heatgently on a hot plate until the melt dissolves.9.8 Filter the solution (9.7) through a 0.45-m
29、filter, using a500-mL filter flask as a receiver. Wash crucibles with fourapproximately 20-mL portions of deionized water. Combinefiltrate with solution in beaker (see 9.5). Wash the filter flaskwith three approximately 20-mL portions of deionized water,adding washings to beaker.9.9 Add 20 mL of amm
30、onium citrate to solution. Heat to 70to 80C on a steam bath. Add 10 drops of methyl red indicatorsolution and adjust pH to the yellow color by careful additionof 25 % of ammonium hydroxide or 10 % of sulfuric acid.9.10 Add 60 mL of 1 % dimethylglyoxime solution. Imme-diately add concentrated ammoniu
31、m hydroxide dropwise untilthe precipitation takes place. Continue dropwise addition untilthe solution reads pH 9 with pH paper. Cover the beaker. Placethe beaker on a steam bath and heat for 30 min to coagulate theprecipitate. Remove from the steam bath, allow to cool to roomtemperature, and check t
32、he pH. If pH is not 9 by pH paper,adjust to that pH.9.11 Allow the precipitate to settle at least 10 h. Test forcomplete precipitation by adjusting pH to 9 if necessary andadding an additional 3 mL of 1 % dimethylglyoxime solution.If precipitation is incomplete, add an additional 5 mL of 1 %dimethyl
33、glyoxime solution and return to steam bath for 30 min.Allow to cool and check again for completion. If precipitationis still incomplete, discard sample. Recheck calculation of thetest specimen size.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC
34、. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D44810429.12 Dry an
35、d weigh a sintered glass crucible containing a3.2-cm fiberglass filter. Record the weight at G0.NOTE 2The use of a 3.2-cm fiber glass filter facilitates filtering andminimized clogging of the pores of the sintered glass frit of the crucible.This makes it easier to clean crucibles for re-use. Weigh t
36、he dry crucibleplus the fiber glass filter prior to the filtration of nickel dimethylglyoxy-mate.9.13 Filter the mixture from 9.11, using a gentle suction,through the crucible and filter as prepared in 9.12. Wash theprecipitate in the crucible five times with water. Dry thecrucible for2hat120C, allo
37、w to cool in a desiccatorcontaining activated 4A molecular sieve and weigh the cru-cible, plus precipitate. Record the weight to nearest 0.1 mg asG3. Return to an oven for 30 min, cool, and weigh again.Repeat until successive weights agree to 0.1 mg.10. Calculations10.1 Calculate the percent solids,
38、 B, using the followingequation:B 5G2G13 100 (1)where:G1= weight of test specimen before calcination andG2= weight of calcined test specimen10.2 Calculate the amount of nickel oxide, using the fol-lowing equation:Nickel as % NiO 5G3 G0! 3 2587B 3 G(2)where:G3= weight of crucible with precipitate, ex
39、pressed tonearest 0.1 mg,G0= weight of crucible plus fiber glass filter, expressed tonearest 0.1 mg,G = weight of the test specimen, andB = percent solids, expressed as number between 0 to100 to two decimal places.11. Precision and Bias411.1 Test ProgramAn interlaboratory study was con-ducted in whi
40、ch the named property was measured in threeseparate test materials in five separate laboratories. PracticeE 691, modified for non-uniform data sets, was followed forthe data reduction. Analysis details are in the research report.411.2 PrecisionPairs of test results obtained by a proce-dure similar t
41、o that described in the study are expected to differin absolute value by less than 2.772 S, where 2.772 S is the95 % probability interval limit on the difference between twotest results, and S is the appropriate estimate of standarddeviation. Definitions and usage are given in TerminologyE 456 and P
42、ractice E 177, respectively.95 % Repeatability 95 % ReproducibilityTest Result(Consensus Mean)Interval(Within Laboratory)Interval(Between Laboratories)54.974 weight % 0.543 weight %(0.99 % of mean)2.467 weight %(4.49 % of mean)14.373 weight % 0.272 weight % 1.323 weight %(1.89 % of mean) (9.20 % of
43、mean)2.916 weight % 0.028 weight % 0.065 weight %(0.97 % of mean) (2.24 % of mean)11.3 BiasThe test method described is without knownbias since there are no reference standards available forcomparison.12. Keywords12.1 alumina-base catalyst; nickelASTM International takes no position respecting the v
44、alidity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is s
45、ubject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headq
46、uarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This stan
47、dard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).4Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D32-1014.D4481043
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